Ruffneck AH-12A Guide

Part No. 5475.Rev.9.04 July 2018 Printed in Canada
AH Series
Advanced Horizontal Unit Heater
Installation, Operation, & Maintenance Instructions
Approved Locations
The Forced Air Heaters are CSA listed, certied for the following locations:
Class I, Division 1 & 2, Groups C & D;
Class II, Division 1 & 2, Groups E, F, & G;
Class III, Division 1 & 2;
Temperature Code T3B 329˚F (165˚C)
(On Applicable Models Only)
For details of hazardous locations with potential for explosion, refer to the Canadian Electrical Code,
Part 1, Section 18 or National Electrical Code articles 500-516.
ISO 9001
®
WARNING! Read all instructions before installing or using the heater. Please adhere to instructions published in this manual.
Failure to do so may be dangerous and may void certain provisions of your warranty.

Ruffneck™ is a key brand of Thermon Heating Systems Inc.
Copyright © 2018. All rights reserved.
TABLE OF CONTENTS
A. Heater Maintenance Checklist 3
A.1 Period...................................................................................................................3
A.2 Annual.................................................................................................................. 3
B. Important Notices 4
C. Installation 4
C.1 Mechanical...........................................................................................................4
C.2 Motor Wiring Diagrams ........................................................................................8
C.3 Wiring Diagram for Built-in Disconnect Switch Heaters........................................9
D. Model Coding 10
E. Specifications 11
E.1 General............................................................................................................... 11
E.2 Model ................................................................................................................. 11
F. Parts List 12
F.1 AH-12A, AH-16A, AH-20A, AH-24A ..................................................................... 12
F.2 AH-24B ............................................................................................................... 13
F.3 XS40 Disconnect ................................................................................................ 14
G. Repair & Replacement 15
G.1 Motor, Fan, and Fan Guard ................................................................................ 15
G.2 Heat Exchanger Removal of Single -Motor Unit Heater...................................... 16
G.3 Heat Exchanger Removal of Double-Motor Unit Heater..................................... 16

3
Heater Maintenance Checklist
A. HEATER MAINTENANCE CHECKLIST
WARNING
WARNING. Heater should only be serviced by qualied personnel with heating equipment
experience. Lock the switch in the “OFF” (open) position and/or tag the switch to prevent
unexpected power application.
Heater Model
Serial Number
Comments
Date of Maintenance
Maintenance Done By
A.1 Period
1. Clean
Finned Tubes
Fan
Fan Guard
Motor
Louvers
2. Check
Motor for smooth, quiet operation
Louvers for proper angle and tightness
Electrical junction box cover for tightness
Remove dust using compressed air. Do not spray with water or solvents.
A.2 Annual
1. Electrical
Check all terminal connections and conductors.
Tighten loose connections. Conductors with
damaged insulation must be replaced.
2. Mechanical
Check for uid leakage. If any uid leakage occurs
from the heater, remove it from service and have the
heat exchanger replaced. A factory supplied heat
exchanger can be shipped in less than a week from
stock. Refer to Section G. Repair & Replacement,
page15 section for details.
Electrical junction box. Inside of enclosure must be
clean, dry, and free of foreign materials. Cover must
be completely on and tight.
Check motor shaft bearing play. Replace motor if
play is excessive or if motor does not run quietly and
smoothly. Motor bearings are permanently lubricated.
Check fan. Replace immediately if cracked or
damaged.
Check louvers. Louver screws should be tight.
Louvers are not to be closed more than 75˚ from
horizontal.
Check the tightness of all hardware. All nuts and
bolts, including mounting hardware, must be tight.
TURN HEATER MOTOR ON FOR A MINIMUM OF
15 MINUTES. Check for air exiting heater through
louvers and smooth running of fan motor.
Photocopy
this page
for reuse.
(before and as required during heating season)
(before heating season)
For assistance, please call
Toll Free: 1-800-661-8529
U.S. & Canada

4
Important Notices / Installation
B. IMPORTANT NOTICES
WARNING
WARNING. Read and adhere to the following. Failure to
do so may result in severe or fatal injury.
1. Read and follow the instructions in this manual.
2. Heater to be used only in the hazardous locations
indicated on the heater’s data plate.
3. Heater is for dry indoor use only. Do not immerse in water.
Do not store or use in areas exposed to rain or snow.
4. Heater is to be connected and serviced only by a qualied
electrician experienced with hazardous location equipment.
5. Installation, piping, and wiring of the heater must adhere to
all applicable codes.
6. It is essential that any unit heater that will be used in a
hazardous (classied) location is equipped with an electric
motor approved for such service, and the temperature of
the heat transfer medium is below the ignition temperature
of the atmosphere. Refer to applicable electrical codes for
additional information.
7. Disconnect heater from power supply at integral
disconnect or fuse box before opening enclosures or
servicing heater. Lock the switch in the “OFF” (open)
position and/or tag the switch to prevent unexpected
power application. IF INTEGRAL DISCONNECT IS BEING
SERVICED, verify that power has been disconnected
at fuse box or main panel. Lock the switch in the
“OFF” (open) position and/or tag the switch to prevent
unexpected power application.
8. Do not operate heater in atmospheres which are corrosive
to steel or aluminum, unless it has been coated with a
factory approved protective coating.
9. For steam service use only single-pass models. Refer
to Section D. Model Coding, page10 for number of
passes in heat exchanger.
10. Refer to heat exchanger data plate for pressure and
temperature limits.
11. Heater must be kept clean. When operating in a dirty
environment, regularly clean the nned tubes, fan and fan
guard. Follow the recommended maintenance procedures.
Refer to Section A. Heater Maintenance Checklist,
page3 for details.
12. Use factory approved replacement parts only.
13. If there are any questions or concerns regarding the
heater, contact the factory. Refer to the last page of this
manual for details.
14. HVAC uids must be non-ammable, non-compressable,
non-explosive and non-toxic.
15. Do not operate the heater with any of the louvers fully
closed or overriding their stops.
16. Do not operate heater in ambient temperatures above
104°F (40°C).
17. See applicable electrical codes for seal requirements in
eld installed conduits. Factory installed conduits require
no further sealing.
18. Base of the heater is to be mounted a minimum of 7.9ft
(2.4m) above the oor. Refer to Section C. Installation,
page4 for details.
C. INSTALLATION
WARNING
WARNING. Warranty will be void if instructions are not
followed.
The installation instructions provide a general guideline for the
installation and wiring of the heater.
All applicable codes must be adhered to.
C.1 Mechanical
1. For optimum heating, the heaters should be installed as
follows:
1.1 There are no obstructions that may impede the
heater’s air inlet or discharge.
1.2 The air discharge is directed into open areas and not
at occupants.
1.3 The air discharge is not directed at a thermostat.
1.4 The air discharge is directed across areas of heat
loss, such as doors and windows (Figure1).
1.5 The air discharge is directed along, and at a slight
angle towards, exterior walls (see Figure1).
1.6 If equipment freeze protection is important, direct air
discharge at equipment.
1.7 Air discharge streams support each other and create
a circular air ow. It is not required that the heater’s
air throw reaches the next heater.
1.8 For warehouses or large workshops it may be
acceptable to use fewer, larger heaters.
1. Read and follow the instructions in this manual.
2. Heaters are to be installed and serviced only
by qualified personnel experienced in electrical and
piping work.
3. Installation, piping, and wiring of he heater must
adhere to all applicable codes.
4. It is essential that any unit heater that will be used
in a hazardous (classified) location is equipped with
a electric motor approved for such service, and the
temperature of the heat transfer medium is below
the ignition temperature of the atmosphere.
5. Do not operate heater in atmospheres which are
corrosive to steel or aluminum, unless it has been
coated with a factory approved protective coating.
6. For steam service use only single-pass models.
Refer to model coding (page 7) for number of
passes in heat exchanger.
7. Refer to heat exchanger data plate for pressure
and temperature limits.
8. Heater must be kept clean. When operating in
a dirty environment, regularly clean the finned
tubes, fan and fan guard. Follow the recommended
maintenance procedures. Refer to the “Heater
Maintenance Checklist” section for details.
9. Use factory approved replacement parts only.
10. If there are any questions or concerns regarding
the heater, contact the factory. Refer to the last
page of this manual for details.
WARRANTY W I LL B E VOID
I F INSTR U C TIONS ARE NOT FOLLOW E D
INSTALLATION
The installation instructions provide a general guideline for the installation and wiring of the heater.
All applicable codes must be adhered to.
MECHANICAL
LOCATION
1. For optimum heating, the heaters should be installed as
follows:
a. There are no obstructions that may impede the heater’s
air inlet or discharge.
b. The air discharge is directed into open areas and not at
occupants.
c. The air discharge is not directed at a thermostat.
d. The air discharge is directed across areas of heat loss,
such as doors and windows (see Figure 1).
e. The air discharge is directed along, and at a slight angle
towards, exterior walls (see Figure 1).
f. If equipment freeze protection is important, direct air
discharge at equipment.
g. Air discharge streams support each other and create a
circular air flow. It is not required that the heater’s air
throw reaches the next heater.
h. For warehouses or large workshops it may be
acceptable to use fewer, larger heaters.
- 3 -
FIGURE 1
IMPORTANT NOTICES
WARNING:
Read and adhere to the following. Failure to do so may result in severe or fatal injury.
Figure1

5
Installation
2. Mounting
2.1 The unit heater is designed to be installed in an
upright and level position. However, it may be
installed in any position provided that for steam
service the inlet is above the outlet and the bottom
of the heat exchanger drains towards the outlet.
2.2 Heater cabinets are designed to be mounted from
the top or bottom using 1/2" (14mm) bolts. For
heater dimensions, see Figure2, page5 for
single fan or Figure3, page6 for 24" tandem.
2.3 The mounting structure must be strong enough to:
– Support the heater’s weight (refer Section E.
Specications, page11),
– Provide sufcient stiffness to prevent excessive
vibration, and
– Withstand abusive situations such as transportable
installations.
2.4 For ease of installation, a variety of mounting kits are
available from the factory.
3. Mounting Heights
3.1 The base of the heater is to be elevated a minimum
of 7.9ft (2.4m) above the oor.
FIGURE 3
FIGURE 2
AH-24B Tandem
A in. 52-15/16
mm 1345
B in. 31-1/2
mm 800
C in. 4-13/16
mm 122
D in. 7-7/16
mm 189
E in. 24-3/16
mm 615
F in. 58-1/4
mm 1480
G in. 9/16
mm 14.3
H in. 36-7/8
mm 937
I in. 2-1/16
mm 53
J in. 5/8
mm 16
K in. 59-1/2
mm 1512
DIM AH-12A AH-16A AH-20A AH-24A
A in 15-13/16 19-13/16 23-13/16 27-7/8
mm 401 503 605 707
B in 19-7/16 23-1/2 27-1/2 31-1/2
mm 494 596 698 800
C in 4-3/16 4-3/16 4-3/16 4-3/16
mm 107 107 107 107
D in 7-15/16 7-9/16 7-3/16 6-7/8
mm 201 192 183 174
E in 23-5/8 23-5/8 23-5/8 23-5/8
mm 600 600 600 600
F in 18-3/16 22-3/16 26-3/16 30-3/16
mm 462 564 665 766
G in 9/16 9/16 9/16 9/16
mm 14.3 14.3 14.3 14.3
H in 23-7/8 27-7/8 31-7/8 35-7/8
mm 606.5 708.5 809.5 911.5
I in 1-9/16 1-9/16 1-9/16 1-9/16
mm 39 39 39 39
J in 5/8 5/8 5/8 5/8
mm 16 16 16 16
K
in 27-1/2 31-5/8 35-1/2 39-5/8
mm 698.5 802.5 903 1005
L in. 65-1/2
mm 1662.5
FIGURE 3
FIGURE 2
AH-24B Tandem
A in. 52-15/16
mm 1345
B in. 31-1/2
mm 800
C in. 4-13/16
mm 122
D in. 7-7/16
mm 189
E in. 24-3/16
mm 615
F in. 58-1/4
mm 1480
G in. 9/16
mm 14.3
H in. 36-7/8
mm 937
I in. 2-1/16
mm 53
J in. 5/8
mm 16
K in. 59-1/2
mm 1512
DIM AH-12A AH-16A AH-20A AH-24A
A in 15-13/16 19-13/16 23-13/16 27-7/8
mm 401 503 605 707
B in 19-7/16 23-1/2 27-1/2 31-1/2
mm 494 596 698 800
C in 4-3/16 4-3/16 4-3/16 4-3/16
mm 107 107 107 107
D in 7-15/16 7-9/16 7-3/16 6-7/8
mm 201 192 183 174
E in 23-5/8 23-5/8 23-5/8 23-5/8
mm 600 600 600 600
F in 18-3/16 22-3/16 26-3/16 30-3/16
mm 462 564 665 766
G in 9/16 9/16 9/16 9/16
mm 14.3 14.3 14.3 14.3
H in 23-7/8 27-7/8 31-7/8 35-7/8
mm 606.5 708.5 809.5 911.5
I in 1-9/16 1-9/16 1-9/16 1-9/16
mm 39 39 39 39
J in 5/8 5/8 5/8 5/8
mm 16 16 16 16
K
in 27-1/2 31-5/8 35-1/2 39-5/8
mm 698.5 802.5 903 1005
L in. 65-1/2
mm 1662.5
Dim. AH-12A AH-16A AH-20A AH24A
Ain 15-13/16 19 13/16 23-13/16 27-7/8
mm 401 503 605 707
Bin 19-7-16 23-1/2 27-1/2 31-1/2
mm 494 596 698 800
Cin 4-3/16
mm 107
Din 7-15/16 7-9/16 7-3/16 6-7/8
mm 201 192 183 174
Ein 23-5/8
mm 600
Fin 18-3/16 22-3/16 26-3/16 30-3/16
mm 462 564 665 766
Gin 9/16
mm 14.3
Hin 23-7/8 27-7/8 31-7/8 35-7/8
mm 606.5 708.5 809.5 911.5
Iin 1-9/16
mm 39
Jin 5/8
mm 16
Kin 27-1/2 31-5/8 35-1/2 39-5/8
mm 698.5 802.5 903 1005
Figure2
3.2 Heaters maybe mounted at higher elevations and
still provide warm air at the oor level. The maximum
elevation at which warm air will still reach the oor
depends on site and operation conditions.
3.3 Louvers can be adjusted to provide greater
downward deection of the discharge air. It is
recommended that louvers not be closed more than
75° from full open.
4. Mounting Clearances
4.1 Leave at least 20" (500mm) clearance between the
rear of the motor and the nearest obstruction.
4.2 Clearance equal to the height of the heater cabinet
above, or beneath, the cabinet is required for easy
fan or motor replacement.

6
Installation
FIGURE 3
FIGURE 2
AH-24B Tandem
A in. 52-15/16
mm 1345
B in. 31-1/2
mm 800
C in. 4-13/16
mm 122
D in. 7-7/16
mm 189
E in. 24-3/16
mm 615
F in. 58-1/4
mm 1480
G in. 9/16
mm 14.3
H in. 36-7/8
mm 937
I in. 2-1/16
mm 53
J in. 5/8
mm 16
K in. 59-1/2
mm 1512
DIM AH-12A AH-16A AH-20A AH-24A
A in 15-13/16 19-13/16 23-13/16 27-7/8
mm 401 503 605 707
B in 19-7/16 23-1/2 27-1/2 31-1/2
mm 494 596 698 800
C in 4-3/16 4-3/16 4-3/16 4-3/16
mm 107 107 107 107
D in 7-15/16 7-9/16 7-3/16 6-7/8
mm 201 192 183 174
E in 23-5/8 23-5/8 23-5/8 23-5/8
mm 600 600 600 600
F in 18-3/16 22-3/16 26-3/16 30-3/16
mm 462 564 665 766
G in 9/16 9/16 9/16 9/16
mm 14.3 14.3 14.3 14.3
H in 23-7/8 27-7/8 31-7/8 35-7/8
mm 606.5 708.5 809.5 911.5
I in 1-9/16 1-9/16 1-9/16 1-9/16
mm 39 39 39 39
J in 5/8 5/8 5/8 5/8
mm 16 16 16 16
K
in 27-1/2 31-5/8 35-1/2 39-5/8
mm 698.5 802.5 903 1005
L in. 65-1/2
mm 1662.5
Dim. AH-24B Tandem
Ain 52-15/16
mm 1345
Bin 31-1/2
mm 800
Cin 4-13/16
mm 122
Din 7-7/16
mm 189
Ein 24-3/16
mm 615
Fin 58-1/4
mm 1480
Gin 9/16
mm 14.3
Hin 36-7/8
mm 937
Iin 2-1/16
mm 53
Jin 5/8
mm 16
Kin 59-1/2
mm 1512
Lin 65-1/2
mm 1662.5
Figure3
5. Temperature Control
5.1 If required, the unit heater’s output may be
thermostatically controlled by the following:
– Airow through the heat exchanger can be turned
on and off by thermostatically controlling the fan
motor. Usually the ow of the heat transfer medium is
allowed to pass through the heat exchanger without
interruption. This is the most economical method of
controlling the heater.
– Heat transfer medium ow may be controlled by a
thermostatic valve, while allowing the fan motor to
run continuously to circulate room air.
– Absolute control of the heater output from the heat
exchanger will require that the fan and heat transfer
medium be shut off. Such control of the heater
output is possible by a thermostatic valve control in
combination with the thermostatic fan control.
6. Final Inspection
6.1 Before application of electrical power:
– Check that all connections are secured and
comply with the applicable wiring diagram (see
C.2 Motor Wiring Diagrams, page8) and code
requirements.
– Conrm the power supply is compatible with the
data plate rating on motor.
– Remove any foreign objects from heater.
– Ensure all electrical covers are well secured.
– Ensure the fan rotates freely, ensure air exits through
louvers and the fan rotates counterclockwise when
viewed from the rear of the heater.

7
Installation
7. Piping Applications
7.1 For steam service use only single-pass heaters.
Refer to Section D, page10 for tube-side pass
designation.
7.2 Refer to Figure4 and Figure5, page25, and
Figure6, page25 for typical piping applications.
7.3 To prevent condensate from entering the heater,
slope steam supply lines toward the steam main. In
long supply lines, drip traps may be needed.
7.4 For steam systems, use properly sized continuously
draining steam traps, such as oat or thermostatic
types. Traps must be sized to handle start up and
operational ows.
7.5 If the condensate return main is above the heater
outlet or is pressurized, install a check valve after the
steam trap and a drain valve at the strainer to drain
the system during the off season.
7.6 Allow for efcient condensate drainage and
subcooling by maintaining the outlet pipe size
between the heater and steam trap. Provide at least
a 10in (254mm) drop leg at condensate outlet.
7.7 In horizontal steam and condensate lines use
eccentric reducers only.
7.8 Allow for pipe expansion.
7.9 Eliminate pipe stress by adequately supporting all
piping. Do not rely on heater to support piping.
7.10 All piping must be properly sized for expected
ow rates.
7.11 For more piping information, consult industrial piping
handbooks.
7.12 Comply with all applicable piping codes.
PIPING APPLICATIONS
1. For steam service use only single-pass heaters.
Refer to Model Coding Section for tube-side pass
designation.
2. Refer to figures 4-6 for typical piping applications.
3. To prevent condensate from entering the heater, slope
steam supply lines toward the steam main. In long
supply lines, drip traps may be needed.
4. For steam systems, use properly sized continuously
draining steam traps, such as float or thermostatic
types. Traps must be sized to handle start up and
operational flows.
5. If the condensate return main is above the heater
outlet or is pressurized, install a check valve after the
steam trap and a drain valve at the strainer to drain
the system during the off season.
6. Allow for efficient condensate drainage and sub-
cooling by maintaining the outlet pipe size between
the heater and steam trap. Provide at least a 10 inch
(254 mm) drop leg at condensate outlet.
7. In horizontal steam and condensate lines use
eccentric reducers only.
8. Allow for pipe expansion.
9. Eliminate pipe stress by adequately supporting all
piping. Do not rely on heater to support piping.
10. All piping must be properly sized for expected flow
rates.
11. For more piping information, consult industrial piping
handbooks.
12. Comply with all applicable piping codes.
Unit heater connection for
low-pressure steam,
open gravity or vacuum return system.
Unit heater connections to overhead steam
and return mains.
Unit heater connections to
overhead liquid mains
FIGURE 4
FIGURE 5 FIGURE 6
NOTES: 1. This piping arrangement is only for two-position-type control.
Modulating steam control may not provide su ressure to
lift condensate to return main.
2. rosive to steel.
3. Install using proper piping practices.
4. In horizontal pipe runs, use eccentric reducers only.
5. Use a properly sized steam trap.
NOTES: 1. For medium to high pressur
must be used.
2. rosive to steel.
3. Install using proper piping practices.
4. In horizontal pipe runs, use eccentric reducers only.
5. Use a properly sized steam trap.
NOTES: 1. rosive to steel.
2. Install using proper piping practices.
Figure4
PIPING APPLICATIONS
1. For steam service use only single-pass heaters.
Refer to Model Coding Section for tube-side pass
designation.
2. Refer to figures 4-6 for typical piping applications.
3. To prevent condensate from entering the heater, slope
steam supply lines toward the steam main. In long
supply lines, drip traps may be needed.
4. For steam systems, use properly sized continuously
draining steam traps, such as float or thermostatic
types. Traps must be sized to handle start up and
operational flows.
5. If the condensate return main is above the heater
outlet or is pressurized, install a check valve after the
steam trap and a drain valve at the strainer to drain
the system during the off season.
6. Allow for efficient condensate drainage and sub-
cooling by maintaining the outlet pipe size between
the heater and steam trap. Provide at least a 10 inch
(254 mm) drop leg at condensate outlet.
7. In horizontal steam and condensate lines use
eccentric reducers only.
8. Allow for pipe expansion.
9. Eliminate pipe stress by adequately supporting all
piping. Do not rely on heater to support piping.
10. All piping must be properly sized for expected flow
rates.
11. For more piping information, consult industrial piping
handbooks.
12. Comply with all applicable piping codes.
Unit heater connection for
low-pressure steam,
open gravity or vacuum return system.
Unit heater connections to overhead steam
and return mains.
Unit heater connections to
overhead liquid mains
FIGURE 4
FIGURE 5 FIGURE 6
NOTES: 1. This piping arrangement is only for two-position-type control.
Modulating steam control may not provide su ressure to
lift condensate to return main.
2. rosive to steel.
3. Install using proper piping practices.
4. In horizontal pipe runs, use eccentric reducers only.
5. Use a properly sized steam trap.
NOTES: 1. For medium to high pressur
must be used.
2. rosive to steel.
3. Install using proper piping practices.
4. In horizontal pipe runs, use eccentric reducers only.
5. Use a properly sized steam trap.
NOTES: 1. rosive to steel.
2. Install using proper piping practices.
Figure5
PIPING APPLICATIONS
1. For steam service use only single-pass heaters.
Refer to Model Coding Section for tube-side pass
designation.
2. Refer to figures 4-6 for typical piping applications.
3. To prevent condensate from entering the heater, slope
steam supply lines toward the steam main. In long
supply lines, drip traps may be needed.
4. For steam systems, use properly sized continuously
draining steam traps, such as float or thermostatic
types. Traps must be sized to handle start up and
operational flows.
5. If the condensate return main is above the heater
outlet or is pressurized, install a check valve after the
steam trap and a drain valve at the strainer to drain
the system during the off season.
6. Allow for efficient condensate drainage and sub-
cooling by maintaining the outlet pipe size between
the heater and steam trap. Provide at least a 10 inch
(254 mm) drop leg at condensate outlet.
7. In horizontal steam and condensate lines use
eccentric reducers only.
8. Allow for pipe expansion.
9. Eliminate pipe stress by adequately supporting all
piping. Do not rely on heater to support piping.
10. All piping must be properly sized for expected flow
rates.
11. For more piping information, consult industrial piping
handbooks.
12. Comply with all applicable piping codes.
Unit heater connection for
low-pressure steam,
open gravity or vacuum return system.
Unit heater connections to overhead steam
and return mains.
Unit heater connections to
overhead liquid mains
FIGURE 4
FIGURE 5 FIGURE 6
NOTES: 1. This piping arrangement is only for two-position-type control.
Modulating steam control may not provide su ressure to
lift condensate to return main.
2. rosive to steel.
3. Install using proper piping practices.
4. In horizontal pipe runs, use eccentric reducers only.
5. Use a properly sized steam trap.
NOTES: 1. For medium to high pressur
must be used.
2. rosive to steel.
3. Install using proper piping practices.
4. In horizontal pipe runs, use eccentric reducers only.
5. Use a properly sized steam trap.
NOTES: 1. rosive to steel.
2. Install using proper piping practices.
Figure6

8
Installation
C.2 Motor Wiring Diagrams
CAUTION
CAUTION. Installation must be done by qualied
personnel, and comply with local electricalcodes.
For internal wiring of control devices and starters,
consult device manufacturer. The thermostat must have
an electrical rating equal to or exceeding the rating of the control
device. For wiring of the fan motor, refer to diagram on the
motor. These wires must be connected in series with the motor
controlcircuit.
MOTOR WIRING DIAGRAMS
CAUTION
Installation must be done by qualified personnel, and comply with local electrical codes.
For internal wiring of control devices and starters,
consult device manufacturer. The thermostat must have an electrical rating
equal to or exceeding the rating of the control device. For wiring of the fan motor, refer to diagram on
the motor. These wires must be connected in series with the motor control circuit.
FIGURE 7
- 6 -
MOTOR WIRING DIAGRAMS
CAUTION
Installation must be done by qualified personnel, and comply with local electrical codes.
For internal wiring of control devices and starters,
consult device manufacturer. The thermostat must have an electrical rating
equal to or exceeding the rating of the control device. For wiring of the fan motor, refer to diagram on
the motor. These wires must be connected in series with the motor control circuit.
FIGURE 7
- 6 -
MOTOR WIRING DIAGRAMS
CAUTION
Installation must be done by qualified personnel, and comply with local electrical codes.
For internal wiring of control devices and starters,
consult device manufacturer. The thermostat must have an electrical rating
equal to or exceeding the rating of the control device. For wiring of the fan motor, refer to diagram on
the motor. These wires must be connected in series with the motor control circuit.
FIGURE 7
- 6 -
MOTOR WIRING DIAGRAMS
CAUTION
Installation must be done by qualified personnel, and comply with local electrical codes.
For internal wiring of control devices and starters,
consult device manufacturer. The thermostat must have an electrical rating
equal to or exceeding the rating of the control device. For wiring of the fan motor, refer to diagram on
the motor. These wires must be connected in series with the motor control circuit.
FIGURE 7
- 6 -

9
Installation
C.3 Wiring Diagram for Built-in Disconnect Switch Heaters
SINGLE PHASE Tandem Motor Unit
SINGLE PHASE
Single Motor Unit
THREE PHASE
Tandem Motor Unit
THREE PHASE

10
Model Coding
AH - 12A - A1A1 - A1 - 1A - D
Model
Series
Model Coding
NOTE:
Thermon Heating Systems Inc. units utilize a standard motor. Specifyingany
other O.E.M. motor may result in longer lead times.
They are approved for use in all provinces and territories in Canada.
Heresite®coated exchangers and cabinets: contact factory for quote.
Louvres and fan blades are also Heresite®coated.
Contact factory for shipping lead time.
Motor designed to be used at rated voltage with tolerances of ±15%.
Motor may be marked 230V, but is suitable for 208V operation.
Tandem conguration not available on AV models.
460 1-phase motors are only certied for groups D, F, and G.
Only available in 16” (406mm) and larger units.
Only availalbe in 24” (610mm) and larger units.
Built-in Disconnect only available with CSA certied heater.
Exchanger Coatings
1 - Heat resistant
aluminum paint
2 - Heresite®
phenolic coating

Heater Certication
1 - General purpose
2 - Explosion-proof,
GroupsC, D, E, F, & G
3 - CSA certifed heater

Connections
A - 1 1/2" NPT Male SCH. 40
B - 1 1/2” (40mm) 300# RF ange
C - 2" NPT Male, SCH. 80
D - 2" (50mm) 300# RF Flange
Built-in
Disconnect
Switch

Fan Size
12A - 12" (305 mm)
16A - 16" (406mm)
20A - 20" (508mm)
24A - 24" (610mm)
24B - 24” (610mm)
Tandem
A = Standard single fan
B = Standard dual fan


Passes
1 - 1 Pass
3 - 3 Passes
5 - 5 Passes
7 - 7 Passes

VPhase Hz
A115 160
B208 160
C208 360
D 230 1 60
E 230 3 60
F460 160
G460 360
H575 360
I220 150
J380 350
K440 350
Motor Electrical Specications







Cabinet Material
A - Epoxy powder coated
carbon steel
B - Heresite®phenolic coated
carbon steel

Discharge Type
1 - 2-way aluminum louvres
2 - Nozzle
3 - 4-way aluminum louvres
Tubing
Wall
Thickeness
Rows
Finning
Fins/inch
Material
Type
in (mm) in (mm)
A5/8
(16)
0.65
(1.7) 310
AL
TW
B1
(25)
0.83
(21) 2 9 EX
C1
(25)
0.135
(3.4) 2 5 EX
Tube Material
D. MODEL CODING

11
Specications
E. SPECIFICATIONS
E.1 General
1. Approvals Class I, Division 1 & 2, Groups C and D;
Class II, Division 1 & 2, Groups E, F, G CRN
(Canada) - Steam and HVAC liquids only. -
CRN OH10951.2C
2. Fan Three blade aluminum, steel spider and hub
with 5/8" bore.
3. Fan Guard Two piece design with close wire spacing.
3/8" diameter probe will not enter. Epoxy
coated to match cabinet color.
4. Mounting Holes 9/16" diameter holes, two at top and two at
bottom of heater.
5. Cabinet Material 14 gauge (0.075") steel. Epoxy coated with
ve-stage pretreatment, including iron
phosphate.
6. Motors CSA and/or UL listed 1725 RPM permanently
lubricated ball bearing type with rigid
base. Explosion-proof or general purpose
construction. All 50 and 60 hertz, standard
voltages available.
7. Louver Blades Anodized extruded aluminum.
8. Header Material 3/16" (0.187") carbon steel.
9. Fluid
Connections
1-1/2" NPT male Sch. 40, 1-1/2" 300# RF
anges, 2" NPT Male Sch. 80 or 2" 300# RF
ange
10. Max. Operating
Pressure
450psi. Refer to Model Specications below
for restrictions.
11. Max Operating
Temperature
6 50 ˚ F.
12. Finned Tubes • 5/8" outside diameter (16 gauge, 0.065"
wall thickness) carbon steel tubes.
Tension wound aluminum ns @ 10 ns
per inch, or
• 1" outside diameter (14 gauge, 0.083"
wall thickness) carbon steel tubes.
Extruded aluminum ns @ 9 ns per
inch, or
• 1" outside diameter (10 gauge, 0.135"
wall thickness) carbon steel tubes.
Extruded aluminum ns @ 5 ns per inch.
13. Optional
Disconnect
XS40 Disconnect Switch suitable for single
and three phase motors.
E.2 Model
Base Model
Air
Delivery**
Air Throw
at
15psi steam Motor***
Requirements
Tube
Passes
Max
Allowable
Pressure
for Steam
Units†
Net
Weight Δ
Shipping
Weight Δ
Net
Weight Δ
w/
Disconnect
Switch
Shipping
Weight Δ
w/
Disconnect
Switch
CFM ft (m) psi lbs lbs lbs lbs
AH-12A-A__ 1150
28’ (8.5m)
1/2 HP
1 or 3 150 102 142 117 167
AH-12A-B__ 116 0 1 or 3 200 107 147 122 172
AH-12A-C1 1030 1300 118 158 133 183
AH-16A-A__ 1840
40’ (12.2m)
1, 3 or 5 135 127 167 142 192
AH-16A-B_ _ 1780 1, 3 or 5 150 138. 178 153 203
AH-16A-C1 1840 1395 153 193 168 218
AH-20A-A__ 2930 1, 3 or 5 180 155 205 180 230
AH-20A-B__ 2700 1, 3 or 5 140 170 220 195 245
AH-20A-C1 3000 1450 195 245 210 270
AH-24A-A__ 3890 1, 3, 5 or 7 165 189 249 204 274
AH-24A-B__ 3640 1, 3, 5 or 7 190 212 272 227 297
AH-24A-C1 3490 1335 258 318 273 343
AH-24B-A__ 7650
65’ (19.8m) (2) 1/2 HP
1, 3, 5 or 7 235 313 413 338 438
AH-24B-B__ 7420 1, 3, 5 or 7 295 376 476 391 501
AH-24B-C1 6690 1450 440 540 455 565
* See Section D. Model Coding, page10.
** At 70˚F and sea level.
*** Ruffneck™ reserves the right to substitute motors of higher horsepower.
Δ Add 12 lbs to anged units.
† Pressure restrictions are for CSA Certified heaters only.

12
Parts List
F. PARTS LIST
F.1 AH-12A, AH-16A, AH-20A, AH-24A
Item Description AH-12A AH-16A AH - 20A AH-24A
1 Panel, AH Top/Bottom 5378 5382 5386 5390
2 Panel, AH Right Side 5376 5380 5384 5388
3 Panel, AH Shroud 5379 5383 5387 5391
4Fan 11284 5449 5450 5451
5 Fan Guard (half) 4087 4088 4089 5396
6Motor ***
7 Bracket, Motor Mount Right 3789 3789 3789 3789
8Channel, Motor Mount 3785 3787 3787 5433
9 Bracket, Motor Mount Left 3788 3788 3788 3788
10 Panel, AH Left Side 5377 5381 5385 5389
11 Heat Exchanger **
12 Kit, Louver (c/w screws) 4075 4076 4077 5741
** Provide complete model and serial number of heater when ordering replacement heat exchanger.
*** Provide motor voltage, phase, horsepower and service classication when ordering replacement motor.
Note: For items not shown, contact factory.
For disconnect parts list, see F.3, page14

13
Parts List
F.2 AH-24B
Item Description AH-24B
1 Panel, AH Top/Bottom 5394
2 Panel, AH Right Side 5392
3 Panel, AH Shroud 5391
4Fan 5451
5 Fan Guard (half) 5396
6Motor ***
7 Bracket, Motor Mount Right 3789
8Channel, Motor Mount 5433
9 Bracket, Motor Mount Left 3788
10 Panel, AH Left Side 5393
11 Heat Exchanger **
12 Kit, Louver (c/w screws) 5742
For disconnect parts list, see F.3, page14

14
Parts List
F.3 XS40 Disconnect
XS40
KIT, XS40 DISC SWTCH ASSM
ANGULAR
CHK'D BY:
APP'D. BY:
SCALE:
DRN BY:
±
DWG NO.:
TITLE:
SYTELINE NO.: METRIC
TOLERANCE UNLESS NOTED OTHERWISE
DECIMAL FRACTIONAL
REVISION DESCRIPTION
REV. BYDATE
1/2° 0.005" 1/16" 1 mm
SHEET:
XS40
lbrauer 19 Dec 2013
±±±
SCALE
EDMONTON, ALBERTA
1 OF 1
6
1
2
1
10
1
1
1
7
1
9
1
4
2
5
1
8
2
3
1
11
1
12
1
Item Number Part Number Description Quantity
1 B16229-03 Terminal Box, X-max Series 2 1
212147 Disconnect Switch Handle 1
312241-02 Operating Shaft 1
4 B12334-01 Terminal Box Cover 2
5 B12676-07 Trolley, Disconnect Switch 1
611362 Bracket, Din Rail 1
712112 Switch, Disconnect 1
8 B12676-07 Terminal Block Ass'y 2
9 XHP100 Dry Seal Plug 1" NPT 1
10 11650 Mounting Bracket 1
11 Contact Manufactuer Cable, Teck-90HL 1
12 Contact Manufacturer Fitting, Teck Cable 1
Item Part Number Description Quantity
1B16229-03 Terminal Box, X-max Series 2 1
212147 Disconnect Switch Handle 1
312241-02 Operating Shaft 1
4B12334-01 Terminal Box Cover 2
5B12676-07 Trolley, Disconnect Switch 1
611362 Bracket, Din Rail 1
712112 Switch, Disconnect 1
8B12676-07 Terminal Block Ass’y 2
9XHP100 Dry Seal Plug 1" NPT 1
10 11650 Mounting Bracket 1
11 Contact Manufacturer Cable, Teck-90HL 1
12 Contact Manufacturer Fitting, Teck Cable 1

15
Repair & Replacement
G. REPAIR & REPLACEMENT
WARNING
WARNING. Heater should only be serviced by qualied
personnel with heating equipment experience. Disconnect
heater from power supply before repairing heater. Lock the
switch in the “OFF” (open) position and/or tag the switch
to prevent unexpected power application. Heater surfaces
may be hot.
After repairing any component:
1. Check that electrical connections are correct and secure.
2. Remove any foreign material from enclosures.
3. Install and secure all covers.
4. Ensure that all fasteners are tight.
5. Remove all foreign objects from heater.
6. Ensure air exits through louvers and fan rotates
counterclockwise when viewed from rear of heater (see
Figure8).
G.1 Motor, Fan, and Fan Guard
1. Remove bolts holding motor to the motor mount.
2. Remove the two piece fan guard assembly (see Figure9).
3. Lift the motor assembly off the motor mount.
4. Before removing the fan, measure and record the location
of the fan hub on the motor shaft (see Figure10). If fan is
difcult to remove, use a gear puller on the fan hub.
5. To reassemble, position fan on motor shaft and tighten
setscrews.
6. Place motor assembly onto motor mount and fasten the
fan guard to cabinet.
7. Center fan in shroud opening. Leave approximately 1/16"
to 3/16" (1.6 to 4.8mm) gap between the motor and fan
guard. (see Figure9).
8. Bolt motor to motor mount. Manually spin the fan blade to
ensure it rotates freely before applying power.
9. Air must exit through louvers and fan must rotate
counterclockwise when viewing from the rear of the heater
(see Figure8).
REPAIR & REPLACEMENT
WARNIN G
Heater should only be serviced by qualified
personnel with heating equipment experience.
Disconnect heater from power supply before
repairing heater. Lock the switch in the
off (open) position and/or tag the switch to
prevent unexpected power application.
Heater surfaces may be hot.
1. After repairing any component:
a. Check that electrical connections are correct and
secure.
b. Remove any foreign material from enclosures,
c. Install and secure all covers.
d. Ensure that all fasteners are tight.
e. Remove all foreign objects from heater.
f. Ensure air exits through louvers and fan rotates
counterclockwise when viewed from rear of heater
(see Figure 9).
MOTOR, FAN, AND
FAN GUARD
1. Remove bolts holding motor to the motor mount.
2. Remove the two piece fan guard assembly (see Figure 10).
3. Lift the motor assembly off the motor mount.
4. Before removing the fan, measure and record the location of
the fan hub on the motor shaft (see Figure 11). If fan is difficult
to remove, use a gear puller on the fan hub.
5. To reassemble, position fan on motor shaft and tighten set
screws.
6. Place motor assembly onto motor mount and fasten the fan
guard to cabinet.
7. Center fan in shroud opening. Leave approximately 1/16” to
3/16” (1.6 to 4.8 mm) gap between the motor and fan guard.
(see Figure 8).
8. Bolt motor to motor mount. Manually spin the fan blade to
ensure it rotates freely before applying power.
9. Air must exit through louvers and fan must rotate
counterclockwise when viewing from the rear of the heater
(see Figure 9).
- 8 -
FIGURE 9
FIGURE 10
FIGURE 11
FIGURE 8 FIGURE 12
1/16” to 3/16”
(1.6 to 4.8 mm)
Support
back of
heater
Fan
rotation
Air intake
Core
Bolts
Motor -
mount
Bolts
Figure7
REPAIR & REPLACEMENT
WARNIN G
Heater should only be serviced by qualified
personnel with heating equipment experience.
Disconnect heater from power supply before
repairing heater. Lock the switch in the
off (open) position and/or tag the switch to
prevent unexpected power application.
Heater surfaces may be hot.
1. After repairing any component:
a. Check that electrical connections are correct and
secure.
b. Remove any foreign material from enclosures,
c. Install and secure all covers.
d. Ensure that all fasteners are tight.
e. Remove all foreign objects from heater.
f. Ensure air exits through louvers and fan rotates
counterclockwise when viewed from rear of heater
(see Figure 9).
MOTOR, FAN, AND
FAN GUARD
1. Remove bolts holding motor to the motor mount.
2. Remove the two piece fan guard assembly (see Figure 10).
3. Lift the motor assembly off the motor mount.
4. Before removing the fan, measure and record the location of
the fan hub on the motor shaft (see Figure 11). If fan is difficult
to remove, use a gear puller on the fan hub.
5. To reassemble, position fan on motor shaft and tighten set
screws.
6. Place motor assembly onto motor mount and fasten the fan
guard to cabinet.
7. Center fan in shroud opening. Leave approximately 1/16” to
3/16” (1.6 to 4.8 mm) gap between the motor and fan guard.
(see Figure 8).
8. Bolt motor to motor mount. Manually spin the fan blade to
ensure it rotates freely before applying power.
9. Air must exit through louvers and fan must rotate
counterclockwise when viewing from the rear of the heater
(see Figure 9).
- 8 -
FIGURE 9
FIGURE 10
FIGURE 11
FIGURE 8 FIGURE 12
1/16” to 3/16”
(1.6 to 4.8 mm)
Support
back of
heater
Fan
rotation
Air intake
Core
Bolts
Motor -
mount
Bolts
Figure8
REPAIR & REPLACEMENT
WARNIN G
Heater should only be serviced by qualified
personnel with heating equipment experience.
Disconnect heater from power supply before
repairing heater. Lock the switch in the
off (open) position and/or tag the switch to
prevent unexpected power application.
Heater surfaces may be hot.
1. After repairing any component:
a. Check that electrical connections are correct and
secure.
b. Remove any foreign material from enclosures,
c. Install and secure all covers.
d. Ensure that all fasteners are tight.
e. Remove all foreign objects from heater.
f. Ensure air exits through louvers and fan rotates
counterclockwise when viewed from rear of heater
(see Figure 9).
MOTOR, FAN, AND
FAN GUARD
1. Remove bolts holding motor to the motor mount.
2. Remove the two piece fan guard assembly (see Figure 10).
3. Lift the motor assembly off the motor mount.
4. Before removing the fan, measure and record the location of
the fan hub on the motor shaft (see Figure 11). If fan is difficult
to remove, use a gear puller on the fan hub.
5. To reassemble, position fan on motor shaft and tighten set
screws.
6. Place motor assembly onto motor mount and fasten the fan
guard to cabinet.
7. Center fan in shroud opening. Leave approximately 1/16” to
3/16” (1.6 to 4.8 mm) gap between the motor and fan guard.
(see Figure 8).
8. Bolt motor to motor mount. Manually spin the fan blade to
ensure it rotates freely before applying power.
9. Air must exit through louvers and fan must rotate
counterclockwise when viewing from the rear of the heater
(see Figure 9).
- 8 -
FIGURE 9
FIGURE 10
FIGURE 11
FIGURE 8 FIGURE 12
1/16” to 3/16”
(1.6 to 4.8 mm)
Support
back of
heater
Fan
rotation
Air intake
Core
Bolts
Motor -
mount
Bolts
Figure9
REPAIR & REPLACEMENT
WARNIN G
Heater should only be serviced by qualified
personnel with heating equipment experience.
Disconnect heater from power supply before
repairing heater. Lock the switch in the
off (open) position and/or tag the switch to
prevent unexpected power application.
Heater surfaces may be hot.
1. After repairing any component:
a. Check that electrical connections are correct and
secure.
b. Remove any foreign material from enclosures,
c. Install and secure all covers.
d. Ensure that all fasteners are tight.
e. Remove all foreign objects from heater.
f. Ensure air exits through louvers and fan rotates
counterclockwise when viewed from rear of heater
(see Figure 9).
MOTOR, FAN, AND
FAN GUARD
1. Remove bolts holding motor to the motor mount.
2. Remove the two piece fan guard assembly (see Figure 10).
3. Lift the motor assembly off the motor mount.
4. Before removing the fan, measure and record the location of
the fan hub on the motor shaft (see Figure 11). If fan is difficult
to remove, use a gear puller on the fan hub.
5. To reassemble, position fan on motor shaft and tighten set
screws.
6. Place motor assembly onto motor mount and fasten the fan
guard to cabinet.
7. Center fan in shroud opening. Leave approximately 1/16” to
3/16” (1.6 to 4.8 mm) gap between the motor and fan guard.
(see Figure 8).
8. Bolt motor to motor mount. Manually spin the fan blade to
ensure it rotates freely before applying power.
9. Air must exit through louvers and fan must rotate
counterclockwise when viewing from the rear of the heater
(see Figure 9).
- 8 -
FIGURE 9
FIGURE 10
FIGURE 11
FIGURE 8 FIGURE 12
1/16” to 3/16”
(1.6 to 4.8 mm)
Support
back of
heater
Fan
rotation
Air intake
Core
Bolts
Motor -
mount
Bolts
Figure10
REPAIR & REPLACEMENT
WARNIN G
Heater should only be serviced by qualified
personnel with heating equipment experience.
Disconnect heater from power supply before
repairing heater. Lock the switch in the
off (open) position and/or tag the switch to
prevent unexpected power application.
Heater surfaces may be hot.
1. After repairing any component:
a. Check that electrical connections are correct and
secure.
b. Remove any foreign material from enclosures,
c. Install and secure all covers.
d. Ensure that all fasteners are tight.
e. Remove all foreign objects from heater.
f. Ensure air exits through louvers and fan rotates
counterclockwise when viewed from rear of heater
(see Figure 9).
MOTOR, FAN, AND
FAN GUARD
1. Remove bolts holding motor to the motor mount.
2. Remove the two piece fan guard assembly (see Figure 10).
3. Lift the motor assembly off the motor mount.
4. Before removing the fan, measure and record the location of
the fan hub on the motor shaft (see Figure 11). If fan is difficult
to remove, use a gear puller on the fan hub.
5. To reassemble, position fan on motor shaft and tighten set
screws.
6. Place motor assembly onto motor mount and fasten the fan
guard to cabinet.
7. Center fan in shroud opening. Leave approximately 1/16” to
3/16” (1.6 to 4.8 mm) gap between the motor and fan guard.
(see Figure 8).
8. Bolt motor to motor mount. Manually spin the fan blade to
ensure it rotates freely before applying power.
9. Air must exit through louvers and fan must rotate
counterclockwise when viewing from the rear of the heater
(see Figure 9).
- 8 -
FIGURE 9
FIGURE 10
FIGURE 11
FIGURE 8 FIGURE 12
1/16” to 3/16”
(1.6 to 4.8 mm)
Support
back of
heater
Fan
rotation
Air intake
Core
Bolts
Motor -
mount
Bolts
Figure11

16
Repair & Replacement
G.2 Heat Exchanger Removal of Single -Motor Unit Heater
1. Remove unit heater from its mounted location and lower to
a stable working surface.
2. Remove all louver blades from the front of the cabinet.
3. Remove the left fan guard and left cabinet side panel
as described below. If the heat exchanger has anged
connections, also remove the top cabinet panel.
4. Support the weight of the heat exchanger by the piping
connection while removing the four core bolts that fasten
the heat exchanger to the cabinet. (See Figure8). Allow
heat exchanger to rest on the bottom of the cabinet.
5. Remove the two bolts holding the motor mount to the left
side of the cabinet. Support motor mount while removing
these two bolts. Once cabinet side has been removed,
reinsert the bolts in the motor mount. Place a support
under the motor mount to prevent the cabinet from rolling
over during heat exchanger removal (see Figure11).
6. With the cabinet side removed and motor mount
supported, slide heat exchanger out of the cabinet. (see
Figure 13). On larger units, assistance may be necessary
due to the weight of the heat exchanger.
7. To install heat exchanger into cabinet, reverse order of heat
exchanger removal procedure.
G.3 Heat Exchanger Removal of Double-Motor Unit Heater
(Due to the weight of the heat exchanger, an assistant is
recommended to help with the following procedure.)
1. Remove unit heater from its mounted location and
lower to a stable work surface. To prevent damage to
the bottom piping connection, do not rest heater on
connection while servicing.
2. Remove all louvers from the front of the cabinet.
3. Remove the top cabinet panel by removing the four
bolts in the corners of the top panel and the fasteners
along the top of the shrouds (see Figure13).
4. Have an assistant support the weight of the heat
exchanger while removing the eight bolts that fasten the
heat exchanger to the cabinet (see Figure14). Once the
bolts on one side are removed, lower that side of the
heat exchanger to rest on the bottom of the cabinet.
Place a support under the motor mount of the cabinet
to prevent the cabinet from rolling over during heat
exchanger removal (see Figure13).
5. Loosen cabinet side panel fasteners but do not remove.
If the heat exchanger has anged connections also
remove the left side panel.
6. Lift the heat exchanger up and out through the front of
the cabinet (see Figure15).
7. To install heat exchanger procedure, reverse the order
of heat exchanger removal procedure.
Support back
of heater
HEAT EXCHANGER REMOVAL OF
SINGLE- MOTOR UNIT HEATER
1. Remove unit heater from its mounted location and
lower to a stable working surface.
2. Remove all louver blades from the front of
the cabinet.
3. Remove the left fan guard and left cabinet
side panel as described below. If the heat exchanger
has flanged connections, also remove the top
cabinet panel.
4. Support the weight of the heat exchanger by the
piping connection while removing the four core bolts
that fasten the heat exchanger to the cabinet. (See
figure 9). Allow heat exchanger to rest on the bottom
of the cabinet.
5. Remove the two bolts holding the motor mount to
the left side of the cabinet. Support motor mount while
removing these two bolts. Once cabinet side has
been removed, reinsert the bolts in the motor
mount. Place a support under the motor mount to
prevent the cabinet from rolling over during heat
exchanger removal (see Figure 12).
6. With the cabinet side removed and motor mount
supported, slide heat exchanger out of the cabinet.
(see Figure 13). On larger units, assistance may be
necessary due to the weight of the heat exchanger.
7. To install heat exchanger into cabinet, reverse order
of heat exchanger removal procedure.
HEAT EXCHANGER REMOVAL OF
DOUBLE-MOTOR UNIT HEATER
(Due to the weight of the heat exchanger, an assistant is
recommended to help with the following procedure.)
1. Remove unit heater from its mounted location and
lower to a stable work surface. To prevent damage to
the bottom piping connection, do not rest heater on
connection while servicing.
2. Remove all louvers from the front of the cabinet.
3. Remove the top cabinet panel by removing the four
bolts in the corners of the top panel and the fasteners
along the top of the shrouds (see Figure 14).
4. Have an assistant support the weight of the heat
exchanger while removing the eight bolts that fasten
the heat exchanger to the cabinet (see Figure 15).
Once the bolts on one side are removed, lower that
side of the heat exchanger to rest on the bottom of
the cabinet. Place a support under the motor mount
of the cabinet to prevent the cabinet from rolling over
during heat exchanger removal (see Figure 14).
5. Loosen cabinet side panel fasteners but do
not remove. If the heat exchanger has flanged
connections also remove the left side panel.
6. Lift the heat exchanger up and out through the front
of the cabinet (see Figure 16).
7. To install heat exchanger procedure, reverse the
order of heat exchanger removal procedure.
- 9 -
FIGURE 15
FIGURE 14
FIGURE 16
FIGURE 13
Figure12
Support back
of heater
HEAT EXCHANGER REMOVAL OF
SINGLE- MOTOR UNIT HEATER
1. Remove unit heater from its mounted location and
lower to a stable working surface.
2. Remove all louver blades from the front of
the cabinet.
3. Remove the left fan guard and left cabinet
side panel as described below. If the heat exchanger
has flanged connections, also remove the top
cabinet panel.
4. Support the weight of the heat exchanger by the
piping connection while removing the four core bolts
that fasten the heat exchanger to the cabinet. (See
figure 9). Allow heat exchanger to rest on the bottom
of the cabinet.
5. Remove the two bolts holding the motor mount to
the left side of the cabinet. Support motor mount while
removing these two bolts. Once cabinet side has
been removed, reinsert the bolts in the motor
mount. Place a support under the motor mount to
prevent the cabinet from rolling over during heat
exchanger removal (see Figure 12).
6. With the cabinet side removed and motor mount
supported, slide heat exchanger out of the cabinet.
(see Figure 13). On larger units, assistance may be
necessary due to the weight of the heat exchanger.
7. To install heat exchanger into cabinet, reverse order
of heat exchanger removal procedure.
HEAT EXCHANGER REMOVAL OF
DOUBLE-MOTOR UNIT HEATER
(Due to the weight of the heat exchanger, an assistant is
recommended to help with the following procedure.)
1. Remove unit heater from its mounted location and
lower to a stable work surface. To prevent damage to
the bottom piping connection, do not rest heater on
connection while servicing.
2. Remove all louvers from the front of the cabinet.
3. Remove the top cabinet panel by removing the four
bolts in the corners of the top panel and the fasteners
along the top of the shrouds (see Figure 14).
4. Have an assistant support the weight of the heat
exchanger while removing the eight bolts that fasten
the heat exchanger to the cabinet (see Figure 15).
Once the bolts on one side are removed, lower that
side of the heat exchanger to rest on the bottom of
the cabinet. Place a support under the motor mount
of the cabinet to prevent the cabinet from rolling over
during heat exchanger removal (see Figure 14).
5. Loosen cabinet side panel fasteners but do
not remove. If the heat exchanger has flanged
connections also remove the left side panel.
6. Lift the heat exchanger up and out through the front
of the cabinet (see Figure 16).
7. To install heat exchanger procedure, reverse the
order of heat exchanger removal procedure.
- 9 -
FIGURE 15
FIGURE 14
FIGURE 16
FIGURE 13
Figure13
Support back
of heater
HEAT EXCHANGER REMOVAL OF
SINGLE- MOTOR UNIT HEATER
1. Remove unit heater from its mounted location and
lower to a stable working surface.
2. Remove all louver blades from the front of
the cabinet.
3. Remove the left fan guard and left cabinet
side panel as described below. If the heat exchanger
has flanged connections, also remove the top
cabinet panel.
4. Support the weight of the heat exchanger by the
piping connection while removing the four core bolts
that fasten the heat exchanger to the cabinet. (See
figure 9). Allow heat exchanger to rest on the bottom
of the cabinet.
5. Remove the two bolts holding the motor mount to
the left side of the cabinet. Support motor mount while
removing these two bolts. Once cabinet side has
been removed, reinsert the bolts in the motor
mount. Place a support under the motor mount to
prevent the cabinet from rolling over during heat
exchanger removal (see Figure 12).
6. With the cabinet side removed and motor mount
supported, slide heat exchanger out of the cabinet.
(see Figure 13). On larger units, assistance may be
necessary due to the weight of the heat exchanger.
7. To install heat exchanger into cabinet, reverse order
of heat exchanger removal procedure.
HEAT EXCHANGER REMOVAL OF
DOUBLE-MOTOR UNIT HEATER
(Due to the weight of the heat exchanger, an assistant is
recommended to help with the following procedure.)
1. Remove unit heater from its mounted location and
lower to a stable work surface. To prevent damage to
the bottom piping connection, do not rest heater on
connection while servicing.
2. Remove all louvers from the front of the cabinet.
3. Remove the top cabinet panel by removing the four
bolts in the corners of the top panel and the fasteners
along the top of the shrouds (see Figure 14).
4. Have an assistant support the weight of the heat
exchanger while removing the eight bolts that fasten
the heat exchanger to the cabinet (see Figure 15).
Once the bolts on one side are removed, lower that
side of the heat exchanger to rest on the bottom of
the cabinet. Place a support under the motor mount
of the cabinet to prevent the cabinet from rolling over
during heat exchanger removal (see Figure 14).
5. Loosen cabinet side panel fasteners but do
not remove. If the heat exchanger has flanged
connections also remove the left side panel.
6. Lift the heat exchanger up and out through the front
of the cabinet (see Figure 16).
7. To install heat exchanger procedure, reverse the
order of heat exchanger removal procedure.
- 9 -
FIGURE 15
FIGURE 14
FIGURE 16
FIGURE 13
Figure14
Support back
of heater
HEAT EXCHANGER REMOVAL OF
SINGLE- MOTOR UNIT HEATER
1. Remove unit heater from its mounted location and
lower to a stable working surface.
2. Remove all louver blades from the front of
the cabinet.
3. Remove the left fan guard and left cabinet
side panel as described below. If the heat exchanger
has flanged connections, also remove the top
cabinet panel.
4. Support the weight of the heat exchanger by the
piping connection while removing the four core bolts
that fasten the heat exchanger to the cabinet. (See
figure 9). Allow heat exchanger to rest on the bottom
of the cabinet.
5. Remove the two bolts holding the motor mount to
the left side of the cabinet. Support motor mount while
removing these two bolts. Once cabinet side has
been removed, reinsert the bolts in the motor
mount. Place a support under the motor mount to
prevent the cabinet from rolling over during heat
exchanger removal (see Figure 12).
6. With the cabinet side removed and motor mount
supported, slide heat exchanger out of the cabinet.
(see Figure 13). On larger units, assistance may be
necessary due to the weight of the heat exchanger.
7. To install heat exchanger into cabinet, reverse order
of heat exchanger removal procedure.
HEAT EXCHANGER REMOVAL OF
DOUBLE-MOTOR UNIT HEATER
(Due to the weight of the heat exchanger, an assistant is
recommended to help with the following procedure.)
1. Remove unit heater from its mounted location and
lower to a stable work surface. To prevent damage to
the bottom piping connection, do not rest heater on
connection while servicing.
2. Remove all louvers from the front of the cabinet.
3. Remove the top cabinet panel by removing the four
bolts in the corners of the top panel and the fasteners
along the top of the shrouds (see Figure 14).
4. Have an assistant support the weight of the heat
exchanger while removing the eight bolts that fasten
the heat exchanger to the cabinet (see Figure 15).
Once the bolts on one side are removed, lower that
side of the heat exchanger to rest on the bottom of
the cabinet. Place a support under the motor mount
of the cabinet to prevent the cabinet from rolling over
during heat exchanger removal (see Figure 14).
5. Loosen cabinet side panel fasteners but do
not remove. If the heat exchanger has flanged
connections also remove the left side panel.
6. Lift the heat exchanger up and out through the front
of the cabinet (see Figure 16).
7. To install heat exchanger procedure, reverse the
order of heat exchanger removal procedure.
- 9 -
FIGURE 15
FIGURE 14
FIGURE 16
FIGURE 13
Figure15

NOTES
NOTES

LIMITED 1-YEAR WARRANTY
Thermon Heating Systems Inc. warrants all Ruffneck™ Advanced Horizontal Series Unit Heaters
against defects in materials and workmanship for a period of one (1) year from date of purchase
on the following terms:
1. We will provide replacement parts free of charge as necessary to restore any unit to
normal operating condition, provided that the inoperative parts be returned to us freight
prepaid and that the replacement parts be accepted freight collect.
2. The complete heater may be returned to our plant for repair or replacement (at our
discretion), provided that all related freight costs be borne by the customer.
3. Corrosion and contamination by dirt, dust, etc. will not be considered as defects and,
therefore, are not warrantable.
4. The heater must not be modied in any way.
5. The heater must be installed, used and stored only in accordance with the owner’s manual
and placarded information. This warranty shall be limited to the actual equipment involved
and, under no circumstances, shall include or extend to installation or removal costs, or to
consequential losses or damages.
PLEASE ADHERE TO INSTRUCTIONS IN THIS MANUAL
Failure to do so may be dangerous and may void certain provisions of
your warranty.
For further assistance, please call 24hr hotline: [phone] (U.S.A. and Canada)
Please have model and serial numbers available before calling.
Oakville
1-800-410-3131
1-905-829-4422
F 905-829-4430
Orillia
1-877-325-3473
1-705-325-3473
F 705-325-2106
WARRANTY:Under normal use the Company warrants to
the purchaser that defects in material or workmanship will be
repaired or replaced without charge for a period of 18 months
from date of shipment, or 12 months from the start date of
operation, whichever expires rst. Any claim for warranty must
be reported to the sales ofce where the product was purchased
for authorized repair or replacement within the terms of this
warranty.
Subject to State or Provincial law to the contrary, the Company
will not be responsible for any expense for installation, removal
from service, transportation, or damages of any type whatsoever,
including damages arising from lack of use, business interruptions,
or incidental or consequential damages.
The Company cannot anticipate or control the conditions of
product usage and therefore accepts no responsibility for
the safe application and suitability of its products when used
alone or in combination with other products. Tests for the
safe application and suitability of the products are the sole
responsibility of the user.
This warranty will be void if, in the judgment of the Company,
the damage, failure or defect is the result of:
• Vibration, radiation, erosion, corrosion, process
contamination, abnormal process conditions, temperature
and pressures, unusual surges or pulsation, fouling,
ordinary wear and tear, lack of maintenance, incorrectly
applied utilities such as voltage, air, gas, water, and others
or any combination of the aforementioned causes not
specically allowed for in the design conditions or,
• Any act or omission by the Purchaser, its agents, servants
or independent contractors which for greater certainty, but
not so as to limit the generality of the foregoing, includes
physical, chemical or mechanical abuse, accident,
improper installation of the product, improper storage
and handling of the product, improper application or the
misalignment of parts.
No warranty applies to paint nishes except for manufacturing defects
apparent within 30 days from the date of installation.
The Company neither assumes nor authorizes any person to assume for it
any other obligation or liability in connection with the product(s).
The Purchaser agrees that all warranty work required after the initial
commissioning of the product will be provided only if the Company
has been paid by the Purchaser in full accordance with the terms and
conditions of the contract.
The Purchaser agrees that the Company makes no warranty or
guarantee, express, implied or statutory, (including any warranty of
merchantability or warranty of tness for a particular purpose) written
or oral, of the Article or incidental labour, except as is expressed or
contained in the agreement herein.
LIABILITY: Technical data contained in the catalog or on the
website is subject to change without notice. The Company reserves
the right to make dimensional and other design changes as required.
The Purchaser acknowledges the Company shall not be obligated
to modify those articles manufactured before the formulation of the
changes in design or improvements of the products by the Company.
The Company shall not be liable to compensate or indemnify the
Purchaser, end user or any other party against any actions, claims,
liabilities, injury, loss, loss of use, loss of business, damages, indirect
or consequential damages, demands, penalties, nes, expenses
(including legal expenses), costs, obligations and causes of action of
any kind arising wholly or partly from negligence or omission of the
user or the misuse, incorrect application, unsafe application, incorrect
storage and handling, incorrect installation, lack of maintenance,
improper maintenance or improper operation of products furnished
by the Company.
Edmonton
1-780-466-3178
F 780-468-5904
5918 Roper Road
Alberta, Canada T6B 3E1
Houston
1-855-219-2101
1-281-506-2310
F 281-506-2316
Denver
1-855-244-3128
1-303-979-7339
F 303-979-7350
PLEASE ADHERE TO INSTRUCTIONS IN THIS MANUAL
Failure to do so may be dangerous and may void certain provisions of
your warranty.
For further assistance, please call 24hr hotline: [phone] (U.S.A. and Canada)
Please have model and serial numbers available before calling.
Oakville
1-800-410-3131
1-905-829-4422
F 905-829-4430
Orillia
1-877-325-3473
1-705-325-3473
F 705-325-2106
WARRANTY:Under normal use the Company warrants to
the purchaser that defects in material or workmanship will be
repaired or replaced without charge for a period of 18 months
from date of shipment, or 12 months from the start date of
operation, whichever expires rst. Any claim for warranty must
be reported to the sales ofce where the product was purchased
for authorized repair or replacement within the terms of this
warranty.
Subject to State or Provincial law to the contrary, the Company
will not be responsible for any expense for installation, removal
from service, transportation, or damages of any type whatsoever,
including damages arising from lack of use, business interruptions,
or incidental or consequential damages.
The Company cannot anticipate or control the conditions of
product usage and therefore accepts no responsibility for
the safe application and suitability of its products when used
alone or in combination with other products. Tests for the
safe application and suitability of the products are the sole
responsibility of the user.
This warranty will be void if, in the judgment of the Company,
the damage, failure or defect is the result of:
• Vibration, radiation, erosion, corrosion, process
contamination, abnormal process conditions, temperature
and pressures, unusual surges or pulsation, fouling,
ordinary wear and tear, lack of maintenance, incorrectly
applied utilities such as voltage, air, gas, water, and others
or any combination of the aforementioned causes not
specically allowed for in the design conditions or,
• Any act or omission by the Purchaser, its agents, servants
or independent contractors which for greater certainty, but
not so as to limit the generality of the foregoing, includes
physical, chemical or mechanical abuse, accident,
improper installation of the product, improper storage
and handling of the product, improper application or the
misalignment of parts.
No warranty applies to paint nishes except for manufacturing defects
apparent within 30 days from the date of installation.
The Company neither assumes nor authorizes any person to assume for it
any other obligation or liability in connection with the product(s).
The Purchaser agrees that all warranty work required after the initial
commissioning of the product will be provided only if the Company
has been paid by the Purchaser in full accordance with the terms and
conditions of the contract.
The Purchaser agrees that the Company makes no warranty or
guarantee, express, implied or statutory, (including any warranty of
merchantability or warranty of tness for a particular purpose) written
or oral, of the Article or incidental labour, except as is expressed or
contained in the agreement herein.
LIABILITY: Technical data contained in the catalog or on the
website is subject to change without notice. The Company reserves
the right to make dimensional and other design changes as required.
The Purchaser acknowledges the Company shall not be obligated
to modify those articles manufactured before the formulation of the
changes in design or improvements of the products by the Company.
The Company shall not be liable to compensate or indemnify the
Purchaser, end user or any other party against any actions, claims,
liabilities, injury, loss, loss of use, loss of business, damages, indirect
or consequential damages, demands, penalties, nes, expenses
(including legal expenses), costs, obligations and causes of action of
any kind arising wholly or partly from negligence or omission of the
user or the misuse, incorrect application, unsafe application, incorrect
storage and handling, incorrect installation, lack of maintenance,
improper maintenance or improper operation of products furnished
by the Company.
Edmonton
1-780-466-3178
F 780-468-5904
5918 Roper Road
Alberta, Canada T6B 3E1
Houston
1-855-219-2101
1-281-506-2310
F 281-506-2316
Denver
1-855-244-3128
1-303-979-7339
F 303-979-7350

Référence5475.Rév.9.04 juillet2018 Imprimé au Canada
Série AH
Unité de chauffage horizontale avancée
Instructions d'installation, d'utilisation et de maintenance
Zones approuvées
Les unités de chauffage à air pulsé sont homologuées CSA et certiées pour les zones suivantes:
Classe I, Division 1ET2, Groupes C ET D;
Classe II, Division 1ET2, Groupes E, F, ET G;
Classe III, Division 1ET2;
Code de température T3B 329˚F (165˚C)
(Sur les modèles concernés uniquement)
Pour plus d'informations sur les zones à risque d'explosion, veuillez consulter le Code canadien de l'électricité,
Partie1, Section18 ou les articles500-516 du Code national de l'électricité.
ATTENTION! Veuillez lire toutes les instructions avant d'installer ou d'utiliser le système de chauffage.
Veuillez respecter les instructions publiées dans ce manuel. Leur non-respect peut s'avérer dangereux
et est susceptible d'annuler certaines dispositions de votre garantie.
Chauffages pour les environnements les plus rigoureux
MC
ISO 9001
®

Ruffneck™ est une marque majeure de Thermon Heating Systems Inc.
Copyright ©2018 Tous droits réservés.
TABLE DES MATIÈRES
A. Liste de contrôle de maintenance – système de chauffage 21
A.1 Période............................................................................................................... 21
A.2 Annuelle ............................................................................................................. 21
B. Remarques importantes 22
C. Installation 23
C.1 Mécanique ......................................................................................................... 23
C.2 Schémas de câblage moteur ............................................................................. 26
C.3 Schéma de câblage pour les systèmes de chauffage à
interrupteurd'isolementintégré............................................................................ 27
D. Codage du modèle 28
E. Caractéristiques 29
E.1 Généralités.......................................................................................................... 30
E.2 Modèle ............................................................................................................... 31
F. Liste des pièces 33
F.1 AH-12A, AH-16A, AH-20A, AH-24A ..................................................................... 33
F.2 AH-24B ............................................................................................................... 34
F.3 Coupe-circuitXS40............................................................................................. 34
G. Réparation et remplacement 35
G.1 Moteur, ventilateur et grille du ventilateur............................................................ 35
G.2 Retrait de l'échangeur de chaleur d'une unité de chauffage monomoteur .............
G.3 Retrait de l'échangeur de chaleur d'une unité de chauffage bimoteur....................