Chromalox CXH-C-03S User manual

1
PF490 CE AM
161-302421-006
March 2016
Installation and Operation Instructions
CXH CE AM
Forced-Air Heater
CXH Series Heaters for Hazardous Locations
0359 II 2
G
EEx d IIB T3
ITS02ATEX1048/8

2
A
D
C
A
B
E
50.8 mm mm
(2”)
50.8
(2”)
281 mm
(11-1/16”)
Table A - Specifications
Model kW Voltage and Phase
Horiz. Air
Discharge
m (ft.) BTUH
CFM
(m3/hr)
Wt.
Kg.
(Lbs.)
Overall Dimensions
mm (In.)
5/8” UNC Tapped
Mounting Hole
Locations mm
(In.)
A B C D E
CXH-C-03S 3 380/400/415V 3ph 50Hz 208/240V-1 or
3ph 60Hz 480/575V 3ph 60Hz
28
(8.5)
10,236 700
(1189)
58
(127)
485.8
(19-1/8)
606.4
(23-7/8)
533.4
(21)
88.9
(3-1/2)
346.1
(13-5/8)
CXH-C-05S 5 380/400/415V 3ph 50Hz 208/240V-1 or
3ph 60Hz 480/575V 3ph 60Hz
28
(8.5)
17,060 700
(1189)
58
(127)
485.8
(19-1/8)
606.4
(23-7/8)
533.4
(21)
88.9
(3-1/2)
346.1
(13-5/8)
CXH-C-07S 7.5 380/400/415V 3ph 50Hz 208/240V-1 or
3ph 60Hz 480/575V 3ph 60Hz
32
(9.8)
25,590 840
(1427)
60
(133)
485.8
(19-1/8)
606.4
(23-7/8)
533.4
(21)
88.9
(3-1/2)
346.1
(13-5/8)
CXH-C-10S 10 240V-1 or 3ph 60Hz 480/575V 3ph 60Hz 32
(9.8)
34,120 840
(1427)
63
(138)
485.8
(19-1/8)
606.4
(23-7/8)
533.4
(21)
88.9
(3-1/2)
346.1
(13-5/8)
CXH-C-10M 10 380/400/415V 3ph 50Hz 47
(14.3)
34,120 1450
(2464)
68
(150)
635
(25)
708
(27-7/8)
533.4
(21)
111.9
(4-13/32)
447.7
(17-5/8)
CXH-C-15M 15 380/400/415V 3ph 50Hz
208/240/480/575V 3ph 60Hz
47
(14.3)
51,180 1450
(2464)
68
(150)
635
(25)
708
(27-7/8)
533.4
(21)
111.9
(4-13/32)
447.7
(17-5/8)
CXH-C-20M 20 380/400/415V 3ph 50Hz 480/575V 3ph
60Hz
43
(13.1)
68,240 1450
(2464)
75
(165)
635
(25)
708
(27-7/8)
533.4
(21)
111.9
(4-13/32)
447.7
(17-5/8)
CXH-C-25L 25 380/400/415V 3ph 50Hz 480/575V 3ph
60Hz
54
(16.5)
85,300 3400
(5770)
91
(200)
816
(32-1/8)
809.6
(31-7/8)
552.5
(21-3/4)
139.7
(5-1/2)
549.3
(21-5/8)
CXH-C-30L 30 380/400/415V 3ph 50Hz 480/575V 3ph
60Hz
54
(16.5)
102,360 3400
(5770)
91
(200)
816
(32-1/8)
809.6
(31-7/8)
552.5
(21-3/4)
139.7
(5-1/2)
549.3
(21-5/8)
CXH-C-35L 35 480/575V 3ph 60Hz 54
(16.5)
119,420 3400
(5770)
91
(200)
816
(32-1/8)
809.6
(31-7/8)
552.5
(21-3/4)
139.7
(5-1/2)
549.3
(21-5/8)
CXH-D-05 5 690V 3ph 60Hz 28
(8.5)
17,060 700
(1189)
58
(127)
485.8
(19-1/8)
606.4
(23-7/8)
554.3
(22-5/8)
88.9
(3-1/2)
346.1
(13-5/8)
CXH-D-30 30 690V 3ph 60Hz 54
(16.5)
102,360 3400
(5770)
91
(200)
816
(32-1/8)
809.6
(31-7/8)
552.8
(22-9/16)
139.7
(5-1/2)
549.3
(21-5/8)

3
CXH Forced Air Heater for Hazardous Locations
Failure to understand and follow these installation instructions
and the WARNING notes contained therein may result in se-
vere personal injury, death or substantial property damage.
1. To reduce the risk of ignition of hazardous atmospheres:
In accordance with applicable electric codes, do not in-
stall where operating temperature code exceeds the igni-
tion temperature of the hazardous atmosphere. Use only
in atmospheres having an ignition temperature higher
than 200°C (392°F).
2. Do not open when an explosive gas atmosphere may be
present.
3.
Disconnect from supply circuit before opening enclosures.
4. HAZARD OF ELECTRIC SHOCK. Heater must be ef-
fectively grounded in accordance with applicable electric
codes to eliminate shock hazard.
5. Heat exchanger contains Propylene Glycol under pres-
sure at operating temperature. A material safety data
sheet (MSDS) is available from Chromalox upon request.
Should leakage occur, remove unit from service and in-
vestigate cause.
6. Keep all electrical enclosure covers tightly closed and
secured with all bolts and threads. Cover joints must be
clean before replacing covers.
7. Install and operate in upright position only. Refer to Fig-
ure 3 for level requirements. Failure to comply will cause
overheating of the element and shutting down the unit by
tripping the high temperature cutout.
8. All unused threaded openings not used for supply wiring
must be fitted with threaded plugs approved for use in
hazardous locations.
9. All unit electrical installation fittings, conduit, wiring and
seals must meet applicable electric codes and local
codes for hazardous locations.
10. External line fusing or circuit breaker protection is re-
quired.
11. Hi limit cutouts must never be bypassed in the control
circuit.
12. Mounting clearances on nameplate must be observed.
13. Use copper wire for supply connections according to
size and rating on nameplate.
14. Do not install any type of gasket material on any of the
electrical junction box cover surfaces.
15. Do not attempt to override louver stops or operate unit
with louvers fully closed.
Integral, heavy duty
magnetic contactor
Mounting bolt
hanger connections
Polyester powder-coated
heavy gauge steel corrosion
resistant cabinet
Overpressure
protection device
Heavy gauge adjustable
louver with minimum
opening stops to direct air flow
Removeable front cover
for ease of cleaning
High efficiency heat
exchanger with integral
aluminum-finned steel tubes
Optional service light to
indicate when unit
needs servicing
Built-in 120V control
circuit transformer
(Optional 24V available)
Heavy duty immersion heater assembly
with high temperature cutout(s) and
NEMA 7 & 9 terminal enclosure
Protective housing
for immersion heater
terminal enclosure
Convenient terminal
block for room
thermostat protection
Motor connections
wiring access
Explosion-proof
(NEMA 7 & 9)
controls enclosure
Explosion-proof
motor

4
General Information
The CXH series heaters rated 3 through 35 kW are designed
for operation in Category 2, group IIB, hazardous gas atmo-
spheres having an ignition temperature of 200°C (392°F) or
higher. They are designed for comfort heating and should not
be operated in ambient temperatures less than -20°C (-4°F)
or greater than 40°C (104°F). The units are easily adapted for
wall, ceiling or pole mounting. Refer to Figure 4 on Page 3 for
mounting information.
They are supplied with either 24 or 120V internal control cir-
cuit voltage. The heater is designed for use with an external
hazardous location thermostat or optional built-in thermostat.
The standard heater is designed to operate up to 7500
feet (2,286 m) altitude. Consult factory for specific rec-
ommendations when using the units at higher altitudes.
Installation
FIRE/EXPLOSION HAZARD. Mount only in upright po-
sition and observe nameplate mounting clearances.
Heater Location instructions:
Arrange units so their discharge air streams:
A. are subjected to a minimum of interference from col-
umns, machinery and partitions.
B. wipe exposed walls without blowing directly at them.
C.
are directed away from room occupants in comfort heating.
D. are directed along the windward side when installed in a
building exposed to a prevailing wind.
Locate thermostat on interior partition walls or posts away
from cold drafts, internal heat sources and away from heater
discharge air streams.
Small rooms can be heated by one unit heater. Where two
walls are exposed, the heater should be mounted as shown
in Figure 2. Large rooms require multi-unit installations. Num-
ber and capacity of units will be determined by volume of
building and square feet of floor area to be heated. Arrange
units to provide perimeter air circulation where each unit sup-
ports the air stream from another.
The CXH-C/D hazardous location heaters are designed for
use only in a permanently mounted upright position. We rec-
ommend the use of a mounting kit (ceiling, wall or pole) avail-
able from Chromalox. (Figures 5, 6 and 7)
The ceiling or wall mounting surface and the anchoring provi-
sion must be sufficient to support the combined weights of
the unit and mounting hardware.
If using mounting hardware or a supporting structure not
supplied by Chromalox, the unit should be suspended from
the supporting structure thru the two mounting points on
top of the unit with 5/8 NC bolts and lockwashers. If single
point mounting is desired, order the correct size Chromalox
adapter bracket (P/N 027-302361-001 for 12” fan units, P/N
027-302361-002 for 16” fan units) and P/N 027-302361-003
for 20” fan units. This bracket is designed to hold the unit
over its center of gravity with a 1 dia. bolt. The maximum tilt
angles as shown in Figure 3 must not be exceeded in either
direction during operation and installation.
Failure to comply will cause high limit shut down.
EXPOSED
EXPOSED
EXPOSED
EXPOSED
EXPOSED
EXPOSED
Figure 2

5
1/2" Max
13mm
1/2" Max
13mm
Figure 3
Maximum Out of Plane Allowance
The heaters may be mounted at any convenient height above
floor. The minimum spacings shown in Figure 4 should be
maintained to adjacent walls and ceiling. If floor heat is de-
sired, do not mount higher than 2.5 to 3 meters (8 to 10 feet)
above floor.
Controlling thermostats to individual heaters should be
mounted at shoulder height on inside walls or columns and
clear of the discharge air stream of the unit. Allow at least 1.2
m (4 ft) in front of heater for air stream to discharge freely.
Do not mount mercury type thermostat directly on unit, vibra-
tion could cause malfunction.
Heater may be mounted on a shelf or stand from the bot-
tom. e sure that mounting clearances are maintained and that
bottom of unit has at least 1 clearance underneath it. This
is necessary for good air circulation and servicing of heat
exchanger. All mounting methods must allow for removal of
front cover.
The mounting and anchoring provisions must take into ac-
count the unit vibration and cantilevered loading when wall or
pole mounted. One of the Chromalox mounting kits shown in
Figures 5, 6 and 7 must be used whenever possible.
102mm Min. (4")
204mm
Min.
(8")
102mm
Min.
(4")
2"
5/8 NC (2)
Thds. For
Mounting
Figure 4
Installation Clearances

6
Wall Mount Kit
Model # WMB-12 12” Fan (3-10 kW)
Model # WMB-16 16” Fan (15-20 kW)
Model # WMB-20 20” Fan (25-35 kW)
P
12” Fan - 425.4 mm (16-3/4”)
16” Fan - 469.9 mm
(18-1/2”)
20” Fan - 558.8 mm
(22”)
Wall Bracket
1”ø Hardware % Bolt
Single Point
Swivel Mount
Supplied
1/2 ø Hardware
Not Supplied
Adapter Bracket
& 5/8 NC Hardware
Supplied
139.7 mm (5-1/2”) - 12” Fa
n
130.2 mm (5-1/8”) - 16” Fa
n
161.9 mm (6-3/8”) - 20” Fa
n
CXH-03EP through CXH-10 P= 254 mm (10”)
CXH-10EP through CXH-20 P= 292.1 mm (11-1/2”)
CXH-25EP through CXH-35 P= 368.3 mm (14-1/2”)
Pole or Wall Mount Kit
Model # PMB-12 12” Fan (3-10 kW)
Model # PMB-16 16” Fan (15-20 kW)
Model # PMB-20 20” Fan (25-35 kW)
CXH-03 through CXH-10 P=10”
CXH-10 through CXH-20 P=11-1/2”
CXH-25 through CXH-35 P=14-1/2”
Pole Base
3/8” ø Hardware
Required for
Mounting -
Cust. Supplied
6” Ref.
3-1/2” SCH. 40 Pipe
or 4” O.D. X .25 Wall
Tube Cust. Supplied
Length to Suit
P
A
dapter Bracket
Supplie
d
with 5/8 Bolts
Single Point
Swivel 4”ø
Supplied
Pole Support
Bracket
Heater Mounting
Bracket Arm &
Hardware
ø 3/8 Hardware
Cust. Supplied
ø 1/2 x 4” U-Bolts
& Hardware
Cust. Supplied
Ceiling Mount Kit
Model # HMK-00
4-7/8
4-9/16
Swivel Ceiling
Hanger S/A &
Hardware
5/8” ø Hex Nuts
& Washers
Cust. Supplied ø 1/2
Mounting Hardware.
Bracket Spacing suitable
for use with 4” U-Bolts
Supplied for
Installation
Top & Bottom
ø 5/8 Rods Length
to suit 1” Min.
Threaded Ends
Customer
Supplied
Figure 5
Figure 7
Figure 9
Electrical Components
Pilot Lamp
(Opt.)
Transformer
1” NPT Jumper Wire
Contactor
Heat
Exchanger
Wiring
Compartment
Figure 10
Figure 6
5/8-11 Threaded
Mounting Holes (2)
1/2” NPT
Thermostat Entry
1” NP
T
Top Line Suppl
y
Entry
Unit Top View

7
Wiring and Wiring Diagrams
ELECTRIC SHOCK HAZARD. Disconnect all power
before installing or servicing heater. Failure to do so
could result in personal injury or property damage.
Heater must be installed by a qualified person in ac-
cordance with the National Electrical Code, NFPA 70.
ELECTRIC SHOCK HAZARD. Any installation involv-
ing electric heaters must be performed by a quali-
fied person and must be effectively grounded in
accordance with the National Electrical Code to
eliminate shock hazard.
1. Loosen and remove bolts securing the main terminal
enclosure cover on side of unit. Connect heater to line
supply wires at the box lugs located on the contactor
according the voltage and frequency specified on the
nameplate (see Figure 9). Refer to the appropriate wiring
diagram which also appears on the inside cover of this
enclosure (see Table B and diagrams on page 6).
EXPLOSION HAZARD. Cover joints must be clean be-
fore replacing cover. Do not use any gasket material
on joint surfaces.
2. Use copper conductors only for supply wires. Refer to
nameplate and Table B for size and rating required.
3. Connect supply line ground conductor to the box lug
provided on the base plate below contactor input lugs.
4. The fan motor is factory wired at the same voltage, and
phase as the heating elements. All motors are thermally
protected and connected to the main supply contactor.
On three phase units, it is necessary to verify that the
fan rotation is correct. Air stream discharge must be out
front of unit. After connecting unit to line and closing all
covers tightly, energize unit momentarily. If air does not
exit front louvers, reverse any two supply leads at the box
lugs on the contactor or at the supply disconnect.
5. Either of two 1 NPT rigid conduit openings with integral
stops may be used for connection to supply line. (See
Figure 9 and 10 for locations) Use only NEC approval
hazardous locations means of wiring such as mineral in-
sulated cable and fittings or rigid conduit and seal fittings
located as required by installation codes.
EXPLOSION HAZARD. All unused conduit openings
must be fitted with plugs that are U.L. recognized
for use in hazardous locations.
6. Heaters may be provided with a built-in control switch
and/or thermostat. If not, they should be controlled by an
externally mounted disconnect switch and/or separately
mounted thermostat as shown in the appropriate wiring
diagram on page 6. In case of malfunction, the personnel
in the area should be aware of location of heater discon-
nect.
Table B -Supply Wiring Requirements
Model kW Ph Volts
Supply
Wire 90˚C
Size (ga)
Full
Load
Amps.
Max
Fuse
Amps.
Wiring
Dia.
CXH-C-03S 3 1 208 10 16.9 25 I
CXH-C-03S 3 3 208 12 9.7 15 II
CXH-C-03S 3 1 240 10 14.6 20 I
CXH-C-03S 3 3 240 12 8.4 15 II
CXH-C-03S 3 3 380 12 5.3 15 II
CXH-C-03S 3 3 415 12 4.9 15 II
CXH-C-03S 3 3 480 12 4.2 15 II
CXH-C-03S 3 3 575 12 3.5 15 II
CXH-C-05S 5 1 208 8 27.4 35 I
CXH-C-05S 5 3 208 10 15.9 20 II
CXH-C-05S 5 1 240 8 23.8 30 I
CXH-C-05S 5 3 240 10 13.7 20 II
CXH-C-05S 5 3 380 12 8.7 15 II
CXH-C-05S 5 3 415 12 7.9 15 II
CXH-C-05S 5 3 480 12 6.9 15 II
CXH-C-05S 5 3 575 12 5.7 15 II
CXH-C-07S 7.5 1 208 4 40.6 50 I
CXH-C-07S 7.5 3 208 8 23.5 30 II
CXH-C-07S 7.5 1 240 6 35.2 45 I
CXH-C-07S 7.5 3 240 10 20.4 25 II
CXH-C-07S 7.5 3 380 10 12.9 20 II
CXH-C-07S 7.5 3 415 12 11.8 15 II
CXH-C-07S 7.5 3 480 12 10.2 15 II
CXH-C-07S 7.5 3 575 12 8.5 15 II
CXH-C-10S 10 3 208 6 31.1 40 II
CXH-C-10S 10 1 240 4 46.7 60 I
CXH-C-10S 10 3 240 8 27.0 35 II
CXH-C-10M 10 3 380 10 17.0 25 II
CXH-C-10M 10 3 415 10 15.6 20 II
CXH-C-10S 10 3 480 10 13.5 20 II
CXH-C-10S 10 3 575 12 11.3 15 II
CXH-C-15M 15 3 208 4 46.4 60 II
CXH-C-15M 15 3 240 4 40.2 50 II
CXH-C-15M 15 3 380 8 25.4 35 II
CXH-C-15M 15 3 415 8 23.3 30 II
CXH-C-15M 15 3 480 10 20.1 25 II
CXH-C-15M 15 3 575 10 16.8 20 II
CXH-C-20M 20 3 380 6 33.8 40 II
CXH-C-20M 20 3 415 8 30.9 40 II
CXH-C-20M 20 3 480 8 26.7 35 II
CXH-C-20M 20 3 575 8 22.3 30 II
CXH-C-25L 25 3 380 6 42.1 50 II
CXH-C-25L 25 3 415 6 38.6 50 II
CXH-C-25L 25 3 480 6 33.4 40 II
CXH-C-25L 25 3 575 8 27.9 35 II
CXH-C-30L 30 3 380 4 50.5 60 II
CXH-C-30L 30 3 415 4 46.2 60 II
CXH-C-30L 30 3 480 4 40.0 50 II
CXH-C-30L 30 3 575 6 33.4 40 II
CXH-C-35L 35 3 480 4 46.6 60 II
CXH-C-35L 35 3 575 6 38.9 50 II
CXH-D-05 5 3 690 12 4.8 10 II
CXH-D-30 30 3 690 10 27.8 35 II

8
7. Installation must include appropriate over current protec-
tion devices (fusing or circuit breakers) as required by ap-
plicable electric codes in the supply line to the unit. Refer
to nameplate for proper current ratings.
8. To operate heaters from an externally mounted hazard-
ous location thermostat, a terminal block is provided for
connection (Figures 9 and 10). Remove the factory in-
stalled jumper across T2 and T3 on the terminal strip.
Wire the thermostat contact leads to these terminals. The
built in control transformer supplies the unit with either
24V, 120V, or 230V (690V primary only) for internal unit
operation. This voltage will appear across the thermostat
contacts when they are open. The minimum thermostat
contact rating should be 1 amp @ 120 VAC. Refer to
nameplate for control voltage of unit. The 1/2 NPT con-
duit wiring entry on top of the terminal enclosure should
be used to wire the thermostat to the heater (Figure 10).
9. Protection against overheating is provided by a high
temperature cutout located within the heat exchanger
wiring compartment. (Figure 9) Activation of the control
will open the control circuit and energize the pilot lamp (if
supplied). If normal airflow is restricted, or stopped, the
unit will be cycled off by the high temperature cutout. The
high temperature cutout is also designed to shut down
the unit completely if the fluid level is low or other heater
malfunction occurs.
High Temperature cutout(s) must never be bypassed
in the control circuit. If the limit actuates, shut down
unit and investigate cause of abnormal operation. Do
not reenergize until the problem has been corrected.
Users should install adequate back-up controls and
safety devices with their electric heating equipment.
If the back-up controls are to be located in the haz-
ardous area, they must be approved for use in the
class of location. Where the consequences of failure
may be severe, back-up controls are essential.
Refer to Nameplate
for Input Voltage
1PH
L1 L2
Optional
Disconnet
Switch
GND
Optional Aux. Cont.
L1 L2 L3
Contactor
X1
H1
H2
X2
Primary
Secondary
Control Transformer
Refer to Nameplate for Primary (Input)
and Secondary (Control) Voltage.
Built-In or
External
Thermostat
Connect Thermostat Wires
to the Common and Normally
Closed Terminals of One Pole
on the Thermostat.
Remove this Wire when
Using Thermostat
T3
T2
T1
Optional Alarm
Optional
Elements
Manual Reset
High Limit
Auto Reset
High Limit
Motor
1PH
Terminal
Block
R
Diagram I - 1 PH Wiring
Transformer Color Code Tabulation
PRI
VOLT.
PRI. XFMR
LEAD CLRS.
120V SEC
LEAD CLRS.
24V SEC
LEAD CLRS.
H1 H2 X1 X2 X1 X2
208 BLK RED BLK WHT YEL BLU
240 BLK ORG BLK WHT YEL BLU
380 BLK VIO BLK WHT YEL BLU
415 BLK YEL BLK WHT – –
415 BLK BRN – – YEL BLU
480 BLK BLK/RED BLK WHT YEL BLU
575/600 BLK GRY BLK WHT YEL BLU

9
Refer to Nameplate
for Input Voltage
1PH
L1 L2
Optional
Disconnet
Switch
GND
Optional Aux. Cont.
L1 L2 L3
Heater
Contactor
X1
H1
H2
X2
Primary
Secondary
Control Transformer
Refer to Nameplate for Primary (Input)
and Secondary (Control) Voltage.
Built-In or
External
Thermostat
Connect Thermostat Wires
to the Common and Normally
Closed Terminals of One Pole
on the Thermostat.
Remove this Wire when
Using Thermostat
T3
T2
T1
Optional Alarm
Optional
Elements
Manual Reset
High Limit
Auto Reset
High Limit
Motor
1PH
R
Motor
Contactor
L2 L1
(Red)
Fan
(Heat)
White
Diagram II - 1 PH Wiring with Fan Switch
Transformer Color Code Tabulation
PRI
VOLT.
PRI. XFMR
LEAD CLRS.
120V SEC
LEAD CLRS.
24V SEC
LEAD CLRS.
H1 H2 X1 X2 X1 X2
208 BLK RED BLK WHT YEL BLU
240 BLK ORG BLK WHT YEL BLU
380 BLK VIO BLK WHT YEL BLU
415 BLK YEL BLK WHT – –
415 BLK BRN – – YEL BLU
480 BLK BLK/RED BLK WHT YEL BLU
575/600 BLK GRY BLK WHT YEL BLU

10
Refer to Nameplate
for Input Voltage
3PH
L1 L2 L3
Optional
Disconnet
Switch
GND
Optional Aux. Cont.
L1 L2 L3
Contactor
X1
H1
H2
X2
Primary
Secondary
R
Control Transformer
Refer to Nameplate for Primary (Input)
and Secondary (Control) Voltage.
Built-In or
External
Thermostat Connect Thermostat Wires
to the Common and Normally
Closed Terminals of One Pole
on the Thermostat.
Remove this Wire when
Using Thermostat
T3
T2
T1
Optional Alarm
Optional
Elements
Manual Reset
High Limit
Auto Reset
High Limit
Motor
3PH
Terminal
Block
Diagram III - 3 PH Wiring
Transformer Color Code Tabulation
PRI
VOLT.
PRI. XFMR
LEAD CLRS.
120V SEC
LEAD CLRS.
24V SEC
LEAD CLRS.
H1 H2 X1 X2 X1 X2
208 BLK RED BLK WHT YEL BLU
240 BLK ORG BLK WHT YEL BLU
380 BLK VIO BLK WHT YEL BLU
415 BLK YEL BLK WHT – –
415 BLK BRN – – YEL BLU
480 BLK BLK/RED BLK WHT YEL BLU
575/600 BLK GRY BLK WHT YEL BLU

11
Refer to Nameplate
for Input Voltage
3PH
L1 L2 L3
Optional
Disconnet
Switch
GND
Optional Aux. Cont.
L1 L2 L3
Heater
Contactor
X1
H1
H2
X2
Primary
Secondary
Control Transformer
Refer to Nameplate for Primary (Input)
and Secondary (Control) Voltage.
Built-In or
External
Thermostat
Connect Thermostat Wires
to the Common and Normally
Closed Terminals of One Pole
on the Thermostat.
Remove this Wire when
Using Thermostat
T3
T2
T1
Optional Alarm
Optional
Elements
Manual Reset
High Limit
Auto Reset
High Limit
Motor
3PH
R
Motor
Contactor
L2 L1
(Red)
Fan
Heat
(White)
Diagram IV - 3 PH Wiring with Fan Switch
Transformer Color Code Tabulation
PRI
VOLT.
PRI. XFMR
LEAD CLRS.
120V SEC
LEAD CLRS.
24V SEC
LEAD CLRS.
H1 H2 X1 X2 X1 X2
208 BLK RED BLK WHT YEL BLU
240 BLK ORG BLK WHT YEL BLU
380 BLK VIO BLK WHT YEL BLU
415 BLK YEL BLK WHT – –
415 BLK BRN – – YEL BLU
480 BLK BLK/RED BLK WHT YEL BLU
575/600 BLK GRY BLK WHT YEL BLU
Electric Blower Unit Heater for Hazardous Locations
Heating Element Rating
03 = 3.0 kW 18 = 18.0 kW
05 = 5.0 kW 20 = 20.0 kW
07 = 7.5 kW 25 = 25.0 kW
10 = 10.0 kW 30 = 30.0 kW
15 = 15.0 kW 35 = 35.0 kW
Heater Voltage
2 = 240V 6 = 575V
3 = 380V 8 = 208V
4 = 480V 9 = 600V
5 = 415V
Phase
1 = 1 Phase
3 = 3 Phase
30 = 24V Controls
32 = 120V Controls
00 = No Thermostat
40 = Thermostat
1 = Ethylene Group C & D, E, F, G T3B
2 = Propylene Group C & D, E, F, G T3B
3 = Ethylene Group C, D, F, G T3B
4 = Propylene Group C, D, F, G T3B
0 = No Options
1 = 15 or 30 Amp Disconn. Switch
2 = 60 Amp Disconn. Switch
3 = Pilot Light
4 = Pilot Light and 30 Amp
Disconn. Switch
5 = Pilot Light and 60 Amp
Disconn. Switch
6 = Summer Fan Switch
7 = Summer Fan Switch, Pilot Light
8 = Disconn. Switch with Summer
Fan Switch
9 = Disconn. Switch, Pilot Light
with Summer Fan Switch
CXH-A 104033401 PE1
Explosion Proof
MODEL NUMBER DESCRIPTION

12
Operation
EXPLOSION HAZARD. Heater should not be operated
in ambient temperature higher than 40°C (104°F) or
in atmospheres corrosive to the heater itself.
1. The CXH-C/D unit heaters use a sealed water-glycol filled
heat exchanger. The electric immersion elements transfer
heat energy directly to the fluid generating a fluid/vapor
mixture which releases its heat energy to the finned ra-
diator as it rises and recondenses back to the bottom
reservoir to be reheated. This cycle will continue as long
as fan forced air is available on the finned structure to
remove the heat to the airstream.
2. The finned structure of the heat exchanger must be kept
clean and free of accumulated dust and dirt. The cabi-
net front panel is easily removed providing access to the
heater core for periodic cleaning.
3. Unit should not be operated with louvers fully closed.
Mechanical stops are incorporated into the design of the
cabinet to limit the degree of closure. Do not force the
louvers beyond these stops.
4. If specified, units are supplied with a built in alarm pilot
lamp which will energize if the manual reset control has a
been activated. During unit startup, the lamp will flash on
momentarily to verify its operation.
Maintenance and Repair
Maintenance and repair MUST be performed by qualified personnel only.
EXPLOSION/ELECTRIC SHOCK HAZARD. Disconnect
all power before opening enclosure covers or servic-
ing heater. Failure to comply could result in personal
injury or property damage.
1. Periodically inspect all electrical connections and
terminals to avoid electrical wiring difficulties. In-
spect all wiring for frayed or worn insulation.
2. Periodically and before each heating season, clean
the finned heat exchanger and fan inlet with com-
presses air, vacuum, or water jet. Be sure all electrical
covers are tightly closed.
3. If heat output seems to be low, check amperage draw on
each element. Compare measured values to the correct
currents as listed on the unit nameplate.
4. The thermally protected fan motor is permanently lubri-
cated and sealed. No field servicing is required or should
be attempted.
Replace only with a factory supplied identical motor.
Failure to do so will void the factory warranty and may
expose the user to risk of ignition of hazardous atmo-
spheres.
5. Check fan blade to be sure that set screws are tight and
there are no cracks or looseness in the blades. Use fac-
tory supplied replacement blade only.
6. Check for any sign of leaking from the heat exchanger.
Too little fluid will cause the high temperature cutout(s) to
trip or cycle. Periodically inspect the heater for leaks by
visual examination using a flashlight. Look for evidence
of fluid dunning down the face of the heat exchanger
from the top center. Look for evidence of fluid inside the
lower terminal enclosure and look for any fluid that may
have dripped or pooled in the sheet metal case. If evi-
dence of fluid leaking from the heat exchanger is found,
the unit should be removed from service and the cause
investigated. The heat exchanger is a sealed unit and can
only be serviced by returning to the factory.
7. The sealed heat exchanger contains a glycol/water solu-
tion of propylene glycol. Ethylene glycol is supplied for
arctic duty conditions only. Avoid contact with skin and
eyes. If ingestion should occur, seek medical attention
immediately. In case of eyes or skin contact, wash affect-
ed areas with large amounts of water. The MSDS (Mate-
rial Safety Data Sheet) for these materials is available
upon request.
I. REPLACING THE HEAT EXCHANGER
BURN HAZARD. Be sure heat exchanger and fluid
has been allowed to cool to 43˚C (110°F) before pro-
ceeding.
1. Detach the cabinet front by removing screws from all
sides of unit and pulling cover forward off cabinet shell.
Detach bottom panel by removing two screws on each
side and two screws in the rear. Remove the electrical
control enclosure lid. Disconnect the heater and high limit
wires from the electrical control enclosure. Loosen elec-
trical conduit union located between the heater housing
and the electrical control enclosure. Support the lower
end of the heat exchanger and loosen the three hex head
bolts which hold it to the sheet metal. Lower the heat
exchanger away from the sheet metal. Reverse the above
procedure when installing a new heat exchanger.
II. RESETTING OPTIONAL MANUAL RESET HIGH
TEMPERATURE CUTOUT
EXPLOSION HAZARD. Be sure that all enclosure
covers are replaced and tightly closed before re-en-
ergizing unit after servicing electrical components.
High temperature cutout(s) must never be bypassed
in control circuit.
The factory must perform the replacement of the
immersion heater or high temperature cutout. The
heat exchanger seal must not be broken. Consult
factory for service.
Resetting the cutout multiple times without resolv-
ing the cause of the tripping may allow the heater
to operate in an unsafe condition. Failure to inves-
tigate and resolve a trip condition could result in
personal injury or property damage.

13
Maintenance and Repair
The occurrence of the manual reset limit control to trip is an
abnormal condition. Care should be taken to determine the
exact reason that the high limit control tripped before a man-
ual reset of the limit control. Possible problem areas could
be dirty heat exchanger, blocked air inlet or outlet, fan/motor
malfunction, too high operating ambient, incorrect operating
voltage, or leaking heat exchanger. In the event that the heat
exchanger is defective, it must be replaced.
1. The manual reset limit control is located in the heating
element hazardous location enclosure on the heat ex-
changer which is covered by the sheet metal housing at-
tached to the side of the unit. To gain access, remove the
four sheet metal screws holding the sheet metal cover in
place and unthread the cast aluminum enclosure lid. (See
Figure 11.) The manual reset limit control device has a
small reset button protruding from the center of its back
housing. Depress this button in to reset the control. Re-
place the aluminum enclosure lid and sheet metal cover.
146 mm
(5-3/4")
146 mm
(5-3/4")
Figure 11
III. FAN MOTOR AND BLADE
1. The motor is a sealed unit that requires no lubrication. If
the motor is defective, it must be replaced with an origi-
nal factory supplied motor. (See renewal parts section.)
2. To replace the motor, proceed as follows:
A. Disconnect the unit from power supply.
B. Remove the motor terminal box cover.
C. Note wire connections for future reference and dis-
connect all wires from the motor terminals.
D. Remove 4 bolts in the motor base holding it to the rear
cabinet shelf.
E. Remove 4 screws holding the fan guard to the cabinet.
F. Carefully lift the motor, fan blade, and guard off of the
cabinet.
G. Note position of the fan blade hub on the motor shaft.
Loosen the two set screws to remove the fan blade
from the motor shaft.
Figure 12
Figure 13
H. Place guard and fan blade on replacement motor shaft
in same locations as original motor.
I. Reposition motor back on unit. Center fan blade in
opening and rotate to be sure that it clears housing
and guard.
J. Replace bolts in motor base and reattach fan guard to
back of housing in four places. Recheck blade rotation
and tighten all hardware.
K. Reinstall cable gland into motor terminal box and in-
stall cable.
L. Reconnect wires to motor. Verify correct motor wiring.
Attach ground wire to the connection inside the enclo-
sure. Replace cover and tighten securely.
M. Check fan rotation by momentarily energizing the unit.
Air must exit at cabinet front. Reverse any 2 leads at
contactor or line supply disconnect to reverse rotation
of three phase motor.

14
3. Removal of fan blade does not require that the motor
wiring be disturbed. To clean, service or change the fan
blade proceed as follows:
A. Remove the four carriage bolts holding the motor base
in place on the cabinet platform. Mark the platform to
reposition at same location.
B. Loosen the four screws on the cabinet back holding
the fan guard in place.
C. Pull the motor to the rear extending the conduit con-
nection at the electrical enclosure. Fan blade and hub
set screws can now be accessed by tilting the guard
rearward at top or bottom back over the motor shell.
IV. ELECTRICAL COMPONENT SERVICING
EXPLOSION/ELECTRIC SHOCK HAZARD. Disconnect
all power before opening enclosure covers or ser-
vicing heater. Failure to comply could result in per-
sonal injury or property damage.
When provided, the following components are located in the
cast aluminum hazardous location enclosure. Remove cover
and retaining bolts to gain access the following items (See
Figure 15):
1. CONTROL TRANSFORMER
This item is located in the electrical enclosure. It may be
replaced while in the enclosure. To service or replace re-
move the quick connect wires and mark their locations.
Remove two screws which hold the transformer in place.
Note transformer orientation and voltage labels on top.
Replace transformer in the same orientation and connect
wires. Replace the cast aluminum cover and bolt down.
2. CONTACTOR
This component can be removed from the base plate
while in the enclosure. Follow the same steps as indi-
cated for the transformer replacement.
Figure 14
CXH-C with Optional Pilot Light

15
Renewal Parts Identification
Publication Number Title
PF458 Mounting Kits for Model CXH-EP
PF461 Material Safety Data Sheet Chromakool EG
PF462 Material Safety Data Sheet Chromakool PG
Transformer
Contactor
Figure 15
Electrical Control Voltage 24 V 120 V 230 V
Contactor 072-304551-002 072-304551-008
072-52560-011
Aux Contactor 072-304551-103 072-304551-103 –
Transformer 208/240/480 PRI 315-304252-002 315-304252-001 –
Transformer 380/415 PRI 315-304252-006 315-304252-007 –
Transformer 575 PRI 315-304252-005 315-304252-003 –
Transformer 690 PRI – – 315-304252-012

16
1
33
35
50
19 15
17
16
31
34
52
51
32 25
30
26
44
27
28
29
75
50
27
15 6
62
10
CO
8
12 9
49
15
Figure 16

17
Renewal Parts Identification
Common Parts Shown in Figure 16
Item# Description
Code CXHA-03,
05, 07 & 10
Part No.
CXH-A-15,
18 & 20
Part No.
CXH-A-25,
30 & 35
Part No.
1 Panel wrapper 207-303891-001 207-303891-002 207-303891-003
6 Panel Bottom 207-303881-001 207-303881-002 207-303881-003
8 Panel Front 207-303883-001 207-303883-002 207-303883-003
9 Louver 182-303884-001 182-303884-002 182-303884-003
10 Washer Shoulder 328-302074-002 328-302074-002 328-302074-002
12 Spring 276-130368-001 276-130368-001 276-130368-001
14 Terminal Box Cover 080-302079-001 080-302079-001 080-302079-001
15 Screw 10-32 248-073662-002 248-073662-002 248-073662-002
16 Fan Blade Consult Factory Consult Factory Consult Factory
17 Fan Guard 134-302063-004 134-302063-005 134-302063-006
25 Enclosure 347-304561-001 347-304561-001 347-304561-001
26 Bolt 3/8-16, 1.5 lg 345-075603-263 345-075603-263 345-075603-263
27 Washer flat 328-075528-085 328-075528-085 328-075528-085
28 Washer lock 328-075571-011 328-075571-011 328-075571-011
29 Hex Nut 3/8-16 200-075473-044 200-075473-044 200-075473-044
30 Plug conduit 1/2” 221-302180-001 221-302180-001 221-302180-001
31 Plug conduit 1” 221-302180-003 221-302180-003 221-302180-003
32 Union conduit 3/4” 354-302165-001 354-302165-001 354-302165-001
33 Union conduit 3/4” 354-302243-001 354-302243-001 354-302243-001
34 Conduit Box Consult factory 069-304115-002 069-304115-002
35 Conduit 3/4” Consult factory Consult factory Consult factory
44 Plug conduit 3/4” 221-302180-002 221-302180-002 221-302180-002
50 Bolt 5/16-18 345-075603-218 345-075603-218 345-075603-218
51 Washer 328-075571-010 328-075571-010 328-075571-010
52 Nut 5/16-18 200-075473-039 200-075473-039 200-075473-039
62 Cover Exp. Proof 080-042350-007 080-042350-007 080-042350-007
75 Conduit 3/4” 069-115087-049 069-115087-079 069-115087-093
**Have motor manufacturer and model number availiable when ordering a
replacement motor (ATEX Certified).
***690V heaters - Contact factory for common parts
Motor & Heat Exchanger Parts
Model Heat Exchanger* Item 49
CXH-C-03S-81 353-305234-001
CXH-C-03S-83 353-305234-001
CXH-C-03S-21 353-305234-002
CXH-C-03S-23 353-305234-002
CXH-C-03S-33 353-305234-003
CXH-C-03S-403 353-305234-004
CXH-C-03S-53 353-305234-005
CXH-C-03S-43 353-305234-008
CXH-C-03S-63 353-305234-009
CXH-C-05S-81 353-305234-011
CXH-C-05S-83 353-305234-011
CXH-C-05S-21 353-305234-012
CXH-C-05S-23 353-305234-012
CXH-C-05S-33 353-305234-013
CXH-C-05S-403 353-305234-014
CXH-C-05S-53 353-305234-015
CXH-C-05S-43 353-305234-018
CXH-C-05S-63 353-305234-019
CXH-C-07S-81 353-305235-001
CXH-C-07S-83 353-305235-001
CXH-C-07S-21 353-305235-002
CXH-C-07S-23 353-305235-002
CXH-C-07S-33 353-305235-003
CXH-C-07S-403 353-305235-004
CXH-C-07S-53 353-305235-005
CXH-C-07S-43 353-305235-008
CXH-C-07S-63 353-305235-009
CXH-C-10S-83 353-305235-011
CXH-C-10S-21 353-305235-012
CXH-C-10S-23 353-305235-012
CXH-C-10S-43 353-305235-015
CXH-C-10S-63 353-305235-016
CXH-C-10M-33 353-305236-002
CXH-C-10M-403 353-305236-003
CXH-C-10M-53 353-305236-004
CXH-C-15M-83 353-305236-005
CXH-C-15M-23 353-305236-006
CXH-C-15M-33 353-305236-007
CXH-C-15M-403 353-305236-008
CXH-C-15M-53 353-305236-009
CXH-C-15M-43 353-305236-012
CXH-C-15M-63 353-305236-013
CXH-C-20M-33 353-305236-017
CXH-C-20M-403 353-305236-018
CXH-C-20M-53 353-305236-019
CXH-C-20M-43 353-305236-022
CXH-C-20M-63 353-305236-023
CXH-C-25L-33 353-305237-001
CXH-C-25L-403 353-305237-002
CXH-C-25L-53 353-305237-003
CXH-C-25L-43 353-305237-006
CXH-C-25L-63 353-305237-007
CXH-C-30L-33 353-305237-009
CXH-C-30L-403 353-305237-010
CXH-C-30L-53 353-305237-011
CXH-C-30L-43 353-305237-014
CXH-C-30L-63 353-305237-015
CXH-C-35L-43 353-305237-020
CXH-C-35L-63 353-305237-021
* For arctic duty conditions, heat exchanger with
ethylene glycol are required. Consult factory.
Optional Equipment
Optional Equipment Parts
Description Part Number
Pilot Light (Amber) 213-121103-025
Pilot Light (Red) 213-121103-026
Insulation Fault Relay 072-305296-001
Mounting Kit Adapter
CXH-A-03S through 10S 027-302361-001
CXH-A-15M through 20M 027-302361-002
CXH-A-25L through 35L 027-302361-003
The factory must perform the replacement of the
immersion heater or high temperature cutout. The
heat exchanger seal must not be broken. Consult
factory for service.

18
Limited Warranty:
Please refer to the Chromalox limited warranty applicable to this product at
http://www.chromalox.com/customer-service/policies/termsofsale.aspx.
© 2016 Chromalox, Inc. All rights reserved.
Chromalox
103 Gamma Drive
Pittsburgh, PA 15238
[phone]
www.chromalox.com