Bard SH381 User manual

Manual 2100-410G
Page 1 of 25
INSTALLATION INSTRUCTIONS
WALL MOUNTED
PACKAGE HEAT PUMPS
Models:
SH381
SH431
SH491
Manual : 2100-410G
Supersedes: 2100-410F
File: Volume III Tab 17
Date: 10-21-08
Bard Manufacturing Company, Inc.
Bryan, Ohio 43506
Since 1914....Moving ahead just as planned.

Manual 2100-410G
Page 2 of 25
CONTENTS
Getting Other Informations and Publications 3
Wall Mount General Information
Heat Pump Wall Mount Model Nomenclature.......... 4
Shipping Damage .................................................... 7
General ................................................................ 7
Duct Work................................................................ 7
Filters ................................................................ 7
Fresh Air Intake ....................................................... 8
Condensate Drain – Evaporator ............................. 8
Installation Instructions
Wall Mounting Information....................................... 9
Mounting the Unit .................................................... 9
Wiring – Main Power ............................................. 14
Wiring – Low Voltage Wiring ................................. 14
Optional Outdoor Thermostat Applications ............ 15
Thermostat Indicators ............................................ 17
Start Up
Important Installer Note ......................................... 18
Crankcase Heaters................................................ 18
High Pressure Switch ............................................ 18
Three Phase Scroll Compressor Start Up.............. 18
Phase Monitor ....................................................... 19
Service Hints ......................................................... 19
Sequence of Operation.......................................... 19
Pressure Service Ports.......................................... 19
Defrost Cycle ......................................................... 20
Troubleshooting
Solid State Heat Pump Control
Troubleshooting Procedure ................................... 21
Checking Temperature Sensor Outside
Unit Circuit ............................................................. 22
Temperature vs. Resistance of Temperature ......... 22
Fan Blade Setting Dimensions .............................. 23
Removal of Fan Shroud......................................... 23
Refrigerant Charge ................................................ 23
Pressure Tables ..................................................... 25
Figures
Figure 1 Unit Dimensions...................................... 5
Figure 2 Fresh Air Damper Assembly ................... 8
Figure 3 Mounting Instructions............................ 10
Figure 4 Electric Heat Clearance .........................11
Figure 5 Wall Mounting Instructions.................... 12
Figure 6 Wall Mounting Instructions.................... 12
Figure 7 Common Wall Mounting Installations.... 13
Figure 8 Unit 24V Terminal Board ....................... 14
Figure 9 Compressor Cutoff Thermostat
Wiring ................................................... 15
Figure 10 Compressor Cutoff Thermostat
Wiring ................................................... 15
Figure 11 Electric Heat Hold-Off Wiring................ 16
Figure 12 Electric Heat Hold-Off Wiring................ 16
Figure 13 Start Up Procedure Decal ..................... 18
Figure 14 Defrost Control Board ........................... 20
Figure 15 Fan Blade Setting ................................. 23
Tables
Table 1 Electric Heat Table .................................. 4
Table 2 Electrical Specifications .......................... 6
Table 3 Thermostat Wire Size ........................... 15
Table 4 Wall Thermostat.................................... 17
Table 5 Troubleshooting .................................... 21
Table 6 Fan Blade Dimensions.......................... 23
Table 7 Refrigerant Charge ............................... 23
Table 8 Recommended Operation Range ......... 23
Table 9 Maximum ESP of Operation
Electric Heat Only ................................. 23
Table 10 Indoor Blower Performance .................. 24
Table 11 Pressure Table – Cooling...................... 25
Table 12 Pressure Table – Heating...................... 25

Manual 2100-410G
Page 3 of 25
Getting Other Information and Publications
These publications can help you install the air
conditioner or heat pump. You can usually find these at
your local library or purchase them directly from the
publisher. Be sure to consult current edition of each
standard.
National Electrical Code ...................... ANSI/NFPA 70
Standard for the Installation ...............ANSI/NFPA 90A
of Air Conditioning and Ventilating Systems
Standard for Warm Air ....................... ANSI/NFPA 90B
Heating and Air Conditioning Systems
Load Calculation for ............................ ACCA Manual J
Residential Winter and Summer Air Conditioning
Duct Design for Residential ............... ACCA Manual D
Winter and Summer Air Conditioning and Equipment
Selection
For more information, contact these
publishers:
ACCA Air Conditioning Contractors of America
1712 New Hampshire Ave. N.W.
Washington, DC 20009
Telephone: [phone]
Fax: [phone]
ANSI American National Standards Institute
11 West Street, 13th Floor
New York, NY 10036
Telephone: [phone]
Fax: [phone]
ASHRAE American Society of Heating Refrigerating,
and Air Conditioning Engineers, Inc.
1791 Tullie Circle, N.E.
Atlanta, GA 30329-2305
Telephone: [phone]
Fax: [phone]
NFPA National Fire Protection Association
Batterymarch Park
P.O. Box 9101
Quincy, MA 02269-9901
Telephone: [phone]
Fax: [phone]

Manual 2100-410G
Page 4 of 25
WALL MOUNT GENERAL INFORMATION
HEAT PUMP WALL MOUNT MODEL NOMENCLATURE
SH 38 1 – A 08 X X X X X B
1Vent options are without exhaust capability. May require separate field supplied barometric relief in building.
MODEL NUMBER CONTROL
MODULES
CAPACITY
38 - 3 Ton
43 - 3½ Ton
49 - 4 ton
VOLTS & PHASE
A - 230/208/60/1
B - 230/208/60/3
C - 460/60/3
REVISIONS KW
FILTER OPTIONS
X - 1-Inch Throwaway (Standard)
W - 1-Inch Washable
P - 2-Inch Pleated
COLOR OPTIONS
X - Beige (Standard)
4 - Buckeye Gray
COIL OPTIONS
X - Standard
1 - Phenolic Coated Evaporator
2 - Phenolic Coated Condenser
3 - Phenolic Coated Evaporator
and Condenser
OUTLET OPTIONS
X - Front (Standard)
VENTILATION OPTIONS
B - Blank-off Plate
E - Economizer
M - Motorized Fresh Air Damper 1
P - Commercial Ventilator - Motorized - Power Return w/Exhaust
R - Energy Recovery Ventilator w/Built-In Exhaust
V - Commercial Ventilator - Motorized - Spring Return w/Exhaust
X - Barometric Fresh Air Damper (Standard) 1
TABLE 1
ELECTRIC HEAT TABLE
sledoM
A-183HS A-134HS A-194HS B-183HS B-134HS B-194HS C-183HS C-134HS C-194HS
1-0421-8023-0423-8023-064
WKAUTBAUTBAUTBAUTBAUTB
58.02560711.8100821
64.41005025.21063512.708402
83.33082728.8205402
97.12006037.81030328.0100703
01 6.14031432.6300652

Manual 2100-410G
Page 5 of 25
FIGURE 1
UNIT DIMENSIONS
LEDOM
htdiWhtpeDthgieHylppuSnruteR
)W()D()H(ABCBEFGIJKLMNOPQRST
183HS 134HS 194HS 570.24234.22578.4888.988.9288.5188.9288.3401.9166.1300.0386.2349.6296.4334.2373.388.2488.3200.0100.200.6188.1
BACK VIEW
SIDE VIEWFRONT VIEW

Manual 2100-410G
Page 6 of 25
1Maximum size of the time delay fuse or HACR type circuit breaker for protection of field wiring conductors.
2Based on 75°C copper wire. All Wiring must conform to NEC and all local codes.
3These “Minimum Circuit Ampacity” values are to be used for sizing the field power conductors. Refer to the National Electric
Code (latest revision), article 310 for power conductor sizing.
CAUTION: When more than one field power conductor circuit is run through one conduit, the conductors must be derated.
Pay special attention to note 8 of table 310 regarding Ampacity Adjustment Factors when more than 3 conductors
are in a raceway.
TABLE 2
ELECTRICAL SPECIFICATIONS
ledoM
TIUCRICELGNIS TIUCRICLAUD
detaR &stloV esahP
.oN dleiF rewoP stiucriC
3
muminiM tiucriC yticapmA
1
mumixaM lanretxE roesuF .tiucriC rekaerB
2
dleiF rewoP eriW eziS
2
dnuorG eriW eziS
3
muminiM tiucriC yticapmA
1
mumixaM lanretxE roesuF .tkC rekaerB
2
rewoPdleiF eziSeriW
2
dnuorG eziSeriW
TKCATKCBTKCATKCBTKCATKCBTKCATKCB
Z0A,00A-183HS 50A 80A 01A
1-802/032
12ro1 2ro1 2ro1 13753738 54070809 8
6
4
4
01
8
8
8
--- 131313 ---622425 ---050505 ---035406 ---8
8
8
---01
8
6
---010101 ---010101
Z0B,00B-183HS 60B 90B 3-802/032 1
1
1
321405 535405 8
8
6
010101 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- ---
Z0C,00C-183HS 60C 90C 3-064 1
1
1
311252 515203 410101 410101 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- ---
Z0A,00A-134HS 50A 80A 01A
1-802/032
12ro1 2ro1 2ro1 43066768 05070809 8
6
4
3
01
8
8
8
---434343 ---622425 ---050505 ---035406 ---8
8
8
---01
8
6
---010101 ---010101
Z0B,00B-134HS 60B 90B 3-802/032 1
1
1
523425 530506 8
8
6
010101 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- ---
Z0C,00C-134HS 60C 90C 3-064 1
1
1
412262 025203 210101 210101 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- ---
Z0A,00A-194HS 50A 80A 01A
1-802/032
12ro1 2ro1 2ro1 04662829 060709 001 8
4
4
3
01
8
8
8
---040404 ---622425 ---050505 ---035406 ---8
8
8
---01
8
6
---010101 ---010101
Z0B,00B-194HS 60B 90B 3-802/032 1
1
1
927475 540606 01
8
6
010101 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- ---
Z0C,00C-194HS 60C 90C 3-064 1
1
1
614292 020303 210101 210101 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- ---

Manual 2100-410G
Page 7 of 25
DUCT WORK
Any heat pump is more critical of proper operating
charge and an adequate duct system than a straight air
conditioning unit. All duct work, supply and return,
must be properly sized for the design airflow
requirement of the equipment. Air Conditioning
Contractors of America (ACCA) is an excellent guide to
proper sizing. All duct work or portions thereof not in
the conditioned space should be properly insulated in
order to both conserve energy and prevent condensation
or moisture damage.
Design the duct work according to methods given by the
Air Conditioning Contractors of America (ACCA).
When duct runs through unheated spaces, it should be
insulated with a minimum of one inch of insulation.
Use insulation with a vapor barrier on the outside of the
insulation. Flexible joints should be used to connect the
duct work to the equipment in order to keep the noise
transmission to a minimum.
A 1/4 inch clearance to combustible material for the
first three feet of duct attached to the outlet air frame is
required. See Wall Mounting Instructions and Figures
3, 4, 5 and 6 for further details.
Ducts through the walls must be insulated and all joints
taped or sealed to prevent air or moisture entering the
wall cavity.
Some installations may not require any return air duct.
A metallic return air grille is required with installations
not requiring a return air duct. The spacing between
louvers on the grille shall not be larger than 5/8 inch.
NOTE: If no return air duct is used, applicable
installation codes may limit this cabinet to
installation only in a single story structure.
Any grille that meets with 5/8 inch louver criteria may
be used. It is recommended that Bard Return Air Grille
Kit RG2 through RG5 or RFG2 through RFG5 be
installed when no return duct is used. Contact
distributor or factory for ordering information. If using
a return air filter grille, filters must be of sufficient size
to allow a maximum velocity of 400 fpm.
FILTERS
A 1-inch throwaway filter is supplied with each unit.
The filter slides into position making it easy to service.
This filter can be serviced from the outside by removing
the service door. A 1-inch washable filter and a 2-inch
pleated filter are also available as optional accessories.
The internal filter brackets are adjustable to
accommodate the 2-inch filter by bending down the two
horizontal tabs on each filter bracket.
SHIPPING DAMAGE
Upon receipt of equipment, the carton should be
checked for external signs of shipping damage. If
damage is found, the receiving party must contact the
last carrier immediately, preferably in writing,
requesting inspection by the carrier’s agent.
GENERAL
The equipment covered in this manual is to be installed
by trained, experienced service and installation
technicians.
The refrigerant system is completely assembled and
charged. All internal wiring is complete.
The unit is designed for use with or without duct work.
Flanges are provided for attaching the supply and return
ducts.
These instructions explain the recommended method to
install the air cooled self-contained unit and the
electrical wiring connections to the unit.
These instructions and any instructions packaged with
any separate equipment, required to make up the entire
air conditioning system should be carefully read before
beginning the installation. Note particularly “Starting
Procedure” and any tags and/or labels attached to the
equipment.
While these instructions are intended as a general
recommended guide, they do not supersede any national
and/or local codes in any way. Authorities having
jurisdiction should be consulted before the installation is
made. See Page 3 for information on codes and
standards.
Size of unit for a proposed installation should be based
on heat loss calculation made according to methods of
Air Conditioning Contractors of America (ACCA). The
air duct should be installed in accordance with the
Standards of the National Fire Protection Association
for the Installation of Air Conditioning and Ventilating
Systems of Other Than Residence Type, NFPA No.
90A, and Residence Type Warm Air Heating and Air
Conditioning Systems, NFPA No. 90B. Where local
regulations are at a variance with instructions, installer
should adhere to local codes.

Manual 2100-410G
Page 8 of 25
FRESH AIR INTAKE
All units are built with fresh air inlet slots punched in
the service panel.
If the unit is equipped with a fresh air damper assembly,
the assembly is shipped already attached to the unit.
The damper blade is locked in the closed position. To
allow the damper to operate, the maximum and
minimum blade position stops must be installed. See
Figure 2.
All capacity, efficiency and cost of operation
information as required for Department of Energy
“Energyguide” Fact Sheets is based upon the fresh air
blank-off plate in place and is recommended for
maximum energy efficiency.
The blank-off plate is available upon request from the
factory and is installed in place of the fresh air damper
shipped with each unit.
CONDENSATE DRAIN – EVAPORATOR
A plastic drain hose extends from the drain pan at the
top of the unit down to the unit base. There are
openings in the unit base for the drain hose to pass
through. In the event the drain hose is connected to a
drain system of some type, it must be an open or vented
type system to assure proper drainage.
FIGURE 2
FRESH AIR DAMPER

Manual 2100-410G
Page 9 of 25
INSTALLATION INSTRUCTIONS
WALL MOUNTING INFORMATION
1. Two holes for the supply and return air openings
must be cut through the wall as shown in Figure 3.
2. On wood frame walls, the wall construction must be
strong and rigid enough to carry the weight of the
unit without transmitting any unit vibration.
WARNING
Fire hazard can result if 1/4 inch clearance to
combustible materials for supply air duct is
not maintained. See Figure 3.
3. Concrete block walls must be thoroughly inspected
to insure that they are capable of carrying the weight
of the installed unit.
MOUNTING THE UNIT
1. These units are secured by wall mounting brackets,
which secure the unit to the outside wall surface at
both sides. A bottom mounting bracket is provided
for ease of installation, but is not required.
2. The unit itself is suitable for 0 inch clearance, but
the supply air duct flange and the first 3 feet of
supply air duct require a minimum of 1/4 inch
clearance to combustible material. If a combustible
wall use a minimum of 30½" x 10½" dimensions for
sizing. However, it is generally recommended that a
1-inch clearance is used for ease of installation and
maintaining the required clearance to combustible
material. The supply air opening would then be
32" x 12". See Figures 3 and 4 for details.
WARNING
Failure to provide the 1/4 inch clearance
between the supply duct and a combustible
surface for the first 3 feet of duct can result in
fire causing property damage, injury or death.
3. Locate and mark lag bolt locations and bottom
mounting bracket location. See Figure 3.
4. Mount bottom mounting bracket.
5. Hook top rain flashing under back bend of top. Top
rain flashing is shipped with unit attached to back of
unit on the right side.
6. Position unit in opening and secure with 5/16 lag
bolts; use 3/4 inch diameter flat washers on the lag
bolts.
7. Secure rain flashing to wall and caulk across entire
length of top. See Figure 3.
8. For additional mounting rigidity, the return air and
supply air frames or collars can be drilled and
screwed or welded to the structural wall itself
(depending upon wall construction). Be sure to
observe required clearance if combustible wall.
9. On side-by-side installations, maintain a minimum
of 20 inches clearance on right side to allow access
to control panel and heat strips, and to allow proper
airflow to the outdoor coil. Additional clearance
may be required to meet local or national codes.

Manual 2100-410G
Page 10 of 25
FIGURE 3
MOUNTING INSTRUCTIONS
6 5/8" 6 5/8"
1 7/8"
16" 16" 16" 16" 16"
DIM. "D"
DIM. "B" DIM. "E"
16"
DIM. "A"DIM. "C" DIM. "C"
30"
Supply Opening
Return Opening
Wall Bracket
Wall
Mounting
Hole
Pattern
Front view of wall with unit removed
1/4" clearance on
all (4) sides of
supply air duct
is required from
combustible
materials
Supply Air Duct
Return Air Opening
Wall
Circuit breaker
access door
Heater access panel
Note: It is recommended that a bead of silicone caulking be placed behind the side mounting flanges and under top flashing at time of installation.
MIS-1445 A
Top flashing detail view
Attach supplied rain flashing. Apply caulk between flashing and wall.
Foam air seal
Seal with bead of
caulking along entire
length of top.
Supply flange
Side view of wall with unit installed
DIM. "A" DIM. "B" DIM. "C" DIM. "D" DIM. "E"
Required dimensions to
maintain 1/4" min. clearance
fromcombustible materials 30 1/2" 10 1/2" 6 1/4" 1 1/4" 29 3/4"
Required dimensions to
maintain 1" clearance from
combustible materials 32" 12" 5 1/2" 2" 29"
DIMENSION CHART
DIM. "A" DIM. "B" DIM. "C" DIM. "D" DIM. "E"
Required dimensions to
maintain 1/4" min. clearance
fromcombustible materials 30 1/2" 10 1/2" 6 1/4" 1 1/4" 29 3/4"
Required dimensions to
maintain 1" clearance from
combustible materials 32" 12" 5 1/2" 2" 29"
DIMENSION CHART

Manual 2100-410G
Page 11 of 25
FIGURE 4
ELECTRIC HEAT CLEARANCE
WARNING
A minimum of 1/4 inch clearance must be maintained between the
supply air duct and combustible materials. This is required for the
first 3 feet of ducting.
It is important to insure that the 1/4 inch minimum spacing is
maintained at all points.
Failure to do this could result in overheating the combustible material
and may result in a fire causing property damage, injury or death.
SIDE SECTION VIEW OF SUPPLY AIR DUCT FOR WALL
MOUNTED UNIT SHOWING 1/4 INCH CLEARANCE TO
COMBUSTIBLE SURFACES.

Manual 2100-410G
Page 12 of 25
FIGURE 5
WALL MOUNTING INSTRUCTIONS
FIGURE 6
WALL MOUNTING INSTRUCTIONS
SEE FIGURE 4 – MOUNTING INSTRUCTIONS
SEE UNIT DIMENSIONS, FIGURE 1,
FOR ACTUAL DIMENSIONS

Manual 2100-410G
Page 13 of 25
FIGURE 7
COMMON WALL MOUNTING INSTALLATIONS

Manual 2100-410G
Page 14 of 25
WIRING – MAIN POWER
Refer to the unit rating plate for wire sizing
information and maximum fuse or “HACR” type
circuit breaker size. Each outdoor unit is marked
with a “Minimum Circuit Ampacity”. This means
that the field wiring used must be sized to carry that
amount of current. Depending on the installed KW
of electric heat, there may be two field power
circuits required. If this is the case, the unit serial
plate will so indicate. All models are suitable only
for connection with copper wire. Each unit and/or
wiring diagram will be marked “Use Copper
Conductors Only”. These instructions must be
adhered to. Refer to the National Electrical Code
(NEC) for complete current carrying capacity data
on the various insulation grades of wiring material.
All wiring muse conform to NEC and all local
codes.
The electrical data lists fuse and wire sizes (75° C
copper) for all models including the most commonly
used heater sizes. Also shown are the number of
field power circuits required for the various models
with heaters.
The unit rating plate lists a “Maximum Time Delay
Relay Fuse” or “HACR” type circuit breaker that is
to be used with the equipment. The correct size
must be used for proper circuit protection and also
to assure that there will be no nuisance tripping due
to the momentary high starting current of the
compressor motor.
The disconnect access door on this unit may be
locked to prevent unauthorized access to the
disconnect. To convert for the locking capability,
bend the tab locate in the bottom left hand corner of
the disconnect opening under the disconnect access
panel straight out. This tab will now line up with
the slot in the door. When shut, a padlock may be
placed through the hole in the tab preventing entry.
See “Start Up” section for important information on
three phase scroll compressor start ups.
WIRING – LOW VOLTAGE WIRING
230 / 208V, 1 phase and 3 phase equipment dual
primary voltage transformers. All equipment leaves the
factory wired on 240V tap. For 208V operation,
reconnect from 240V to 208V tap. The acceptable
operating voltage range for the 240 and 208V taps are:
TAP RANGE
240 253 – 216
208 220 – 187
NOTE: The voltage should be measured at the field
power connection point in the unit and while
the unit is operating at full load (maximum
amperage operating condition).
Ten (10) wires should be run from thermostat subbase to
the 24V terminal board in the unit. A nine conductor,
18 gauge copper color-coded thermostat cable is
recommended. The connection points are shown in
Figure 8.
IMPORTANT
Only the thermostats shown in this Manual
have been tested with this equipment for
proper operation. Proper unit operation with
thermostats not listed in this Manual, cannot
be assured.
You assume responsibility for proper
operation of the unit when using thermostats
other than those listed above.
FIGURE 8
UNIT 24V TERMINAL BOARD

Manual 2100-410G
Page 15 of 25
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mumixaM ecnatsiD teeFnI
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geographic region and sizing of the heating equipment to
the individual structure. Utilization of the heating
Application Data, and the heat loss calculation of the
building are useful in determining the correct set points.
NOTE: The additional LAB (low ambient bypass) relay
is required to prevent heater operation during low
temperature cooling operation.
OPTIONAL COMPRESSOR CUTOFF
THERMOSTAT (See Figures 9 and 10)
Heat pump compressor operation at outdoor
temperatures below 0°F are neither desirable nor
advantageous in term of efficiency. An outdoor
thermostat can be applied to take the mechanical heating
(compressor) off line, and send the (compressor) signal
to energize electric heat in its place (to make electric
heat first stage heating). This can also be applied to
bank the quantity of available electric heat. For
example: A heat pump operates with 10KW second
stage heat – once the outdoor thermostat has switched
then operates 15KW without the compressor as first
stage heat.
OPTIONAL OUTDOOR THERMOSTAT
APPLICATIONS
Since most equipment at the time of manufacture is not
designated for any specific destination of the country
and are installed in areas not approaching the lower
outdoor temperature range, outdoor thermostats are not
factory installed as standard equipment, but are offered
as an option. There are also different applications for
applying outdoor thermostats. The set point of either
type of outdoor thermostat application is variable with
FIGURE 10
COMPRESSOR CUTOFF THERMOSTAT WIRING
15 – 20KW 1 PH AND 3 PH
FIGURE 9
COMPRESSOR CUTOFF THERMOSTAT WIRING
4 – 10KW 1 PH – 6 & 9KW 3 PH
TABLE 3
THERMOSTAT WIRE SIZE

Manual 2100-410G
Page 16 of 25
ELECTRIC HEAT HOLD-OFF
(See Figures 11 and 12)
In other applications, it is desirable to disable the
operation of the electric heat until outdoor temperatures
have reached a certain design point. This won't allow
the electric heat to come on as second stage heating
unless the outdoor temperature is below the set point of
the outdoor thermostat. This is done to maximize
efficiency by utilizing the heat pump to bring the
conditioned space temperature up, rather than cycling
on the electric heat due a second stage call for heat from
the thermostat on start-up coming off a night set-back
condition or someone increasing the thermostat set
point. (NOTE: Some programmable thermostats do
have a built-in time delay for pulling in second stage
heat when coming off set-back conditions.)
FIGURE 12
ELECTRIC HEAT HOLD-OFF WIRING
15 – 20KW 1 PH & 3 PH
FIGURE 11
ELECTRIC HEAT HOLD-OFF WIRING
4 – 10KW 1 PH — 6 & 9KW 3 PH

Manual 2100-410G
Page 17 of 25
LOW VOLTAGE CONNECTIONS
These units use a grounded 24 volt AC low voltage
circuit.
The “R” terminal is the hot terminal and the “C”
terminal is grounded.
“G” terminal is the fan input.
“Y” terminal is the compressor input.
“B” terminal is the reversing valve input. The reversing
valve must be energized for heating mode.
“R” terminal is 24 VAC hot.
“C” terminal is 24 VAC grounded.
“L” terminal is compressor lockout output. This
terminal is activated on a high or low pressure trip by
the electronic heat pump control. This is a 24 VAC
output.
LOW VOLTAGE CONNECTIONS
FOR
DDC CONTROL
Fan Only Energize G
Cooling Mode Energize Y, G
Heat Pump Heating Energize Y, G, B
2nd Stg Heating Energize G, W2, Y, B
w/Heat Pump (if employed)
Ventilation Energize G, O1
Emergency Heat Energize B, W2, E, G
TABLE 4
WALL THERMOSTAT
tatsomrehTserutaeFtnanimoderP
850-3048 )1511D0225HT(
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060-3048 )544-0211(
taeHegats3;looCegats3 cinortcelEelbammargorP-noN/elbammargorP revoegnahclaunaMrootuA;lanoitnevnoCroPH
“W2” terminal is second stage heat (if equipped).
“O1” terminal is the ventilation input. This terminal
energizes any factory installed ventilation option.
“E” terminal is the emergency heat input. This terminal
energizes the emergency heat relay.
NOTE: For total and proper control using DDC, a
total of 6 controlled outputs are required (5 if
no ventilation system is installed). For proper
system operation under Emergency Heat
conditions where the compressor needs to be
deactivated, the B-W2-E outputs need to be
energized. Removing the Y (compressor)
signal alone turns the compressor off, but
does not activate the additional circuitry
embedded in the heat pump for proper and
complete operation.

Manual 2100-410G
Page 18 of 25
START UP
IMPORTANT INSTALLER NOTE
For improved start up performance wash the indoor coil
with a dish washing detergent.
CRANKCASE HEATERS
SH491-B and -C are provided with compressor
crankcase heat. All other models are not provided with
crankcase heat. They are either single phase or the
system refrigerant charge is not of sufficient quantity to
require crankcase heat.
The SH491-B and -C models have a wrap around type
heater located on the lower section of the compressor
housing. This is an on/off heater that is controlled by
the compressor contactor.
The label in Figure 13 is affixed to all SH491-B and -C
units detailing start up procedure. This is very
important. Please read carefully.
HIGH PRESSURE SWITCH
All models are supplied with a remote reset high
pressure switch. If tripped, this pressure switch may be
reset by turning the thermostat off then back on again.
THREE PHASE SCROLL COMPRESSOR
START UP INFORMATION
Scroll compressors, like several other types of
compressors, will only compress in one rotational
direction. Direction of rotation is not an issue with
single phase compressors since they will always start
and run in the proper direction.
However, three phase compressors will rotate in either
direction depending upon phasing of the power. Since
there is a 50-50 chance of connecting power in such a
way as to cause rotation in the reverse direction,
verification of proper rotation must be made. All three
phase units incorporate a phase monitor to ensure proper
field wiring. See the “Phase Monitor” section later in
this manual.
Verification of proper rotation must be made any time a
compressor is changed or rewired. If improper rotation
is corrected at this time there will be no negative impact
on the durability of the compressor.
However, reverse operation for over one hour may have
a negative impact on the bearing due to oil pump out.
NOTE: If compressor is allowed to run in reverse
rotation for several minutes, the compressor’s
internal protector will trip.
FIGURE 13
START UP LABEL
All three phase ZR3 compressors are wired identically
internally. As a result, once the correct phasing is
determined for a specific system or installation,
connecting properly phased power leads to the same
Fusite terminal should maintain proper rotation
direction.
Verification of proper rotation direction is made by
observing that suction pressure drops and discharge
pressure rises when the compressor is energized.
Reverse rotation also results in an elevated sound level
over that with correct rotations, as well as, substantially
reduced current draw compared to tabulate values.
The direction of rotation of the compressor may be
changed by reversing any two line connections to the
unit.
IMPORTANT
THESE PROCEDURES MUST BE
FOLLOWED AT INITIAL START UP
AND AT ANY TIME POWER HAS
BEEN REMOVED FOR 12 HOURS
OR LONGER.
To prevent compressor damage which
may result from the presence of liquid
refrigerant in the compressor crankcase:
1. Make certain the room thermostat is in
the “off” position. (The compressor is
not to operate.)
2. Apply power by closing the system
disconnect switch. This energizes the
compressor heater which evaporates
the liquid refrigerant in the crankcase.
3. Allow 4 hours or 60 minutes per pound
of refrigerant in the system as noted
on the unit rating plate, whichever is
greater.
4. After proper elapsed time the
thermostat may be set to operate the
compressor.
5. Except as required for safety while
servicing, do not open system
disconnect switch.
7961-411

Manual 2100-410G
Page 19 of 25
PHASE MONITOR
All units with three phase compressors are equipped
with a 3 phase line monitor to prevent compressor
damage due to phase reversal.
The phase monitor in this unit is equipped with two
LEDs. If the Y signal is present at the phase monitor
and phases are correct, the green LED will light. If
phases are reversed, the red fault LED will be lit and
compressor operation is inhibited.
If a fault condition occurs, reverse two of the supply
leads to the unit. Do not reverse any of the unit factory
wires as damage may occur.
SERVICE HINTS
1. Caution owner/operator to maintain clean air filters
at all times. Also, not to needlessly close off supply
and return air registers. This reduces airflow
through the system, which shortens equipment
service life as well as increasing operating costs.
2. Switching to heating cycle at 75°F or higher outside
temperature may cause a nuisance trip of the remote
reset high pressure switch. Turn thermostat off then
on to reset the high pressure switch.
3. The heat pump wall thermostats perform multiple
functions. Be sure that all function switches are
correctly set for the desired operating mode before
trying to diagnose any reported service problems.
4. Check all power fuses or circuit breakers to be sure
they are the correct rating.
5. Periodic cleaning of the outdoor coil to permit full
and unrestricted airflow circulation is essential.
SEQUENCE OF OPERATION
COOLING – Circuit R-Y makes at thermostat pulling
in compressor contactor, starting the compressor and
outdoor motor. The G (indoor motor) circuit is
automatically completed on any call for cooling
operation or can be energized by manual fan switch on
subbase for constant air circulation.
HEATING – A 24V solenoid coil on reversing valve
controls heating cycle operation. Two thermostat
options, one allowing “Auto” changeover from cycle to
cycle and the other constantly energizing solenoid coil
during heating season and thus eliminating pressure
equalization noise except during defrost, are to be used.
On “Auto” option a circuit is completed from R-W1 and
R-Y on each heating “on” cycle, energizing reversing
valve solenoid and pulling in compressor contactor
starting compressor and outdoor motor. R-G also make
starting indoor blower motor. Heat pump heating cycle
now in operation. The second option has no “Auto”
changeover position, but instead energizes the reversing
valve solenoid constantly whenever the system switch
on subbase is placed in “Heat” position, the “B”
terminal being constantly energized from R. A
thermostat demand for heat completes R-Y circuit,
pulling in compressor contactor starting compressor and
outdoor motor. R-G also make starting indoor blower
motor.
PRESSURE SERVICE PORTS
High and low pressure service ports are installed on all
units so that the system operating pressures can be
observed. Pressure tables can be found later in the
manual covering all models on both cooling and heating
cycles. It is imperative to match the correct pressure
table to the unit by model number.

Manual 2100-410G
Page 20 of 25
DEFROST CYCLE
The defrost cycle is controlled by temperature and time
on the solid state heat pump control. See Figure 14.
When the outdoor temperature is in the lower 40°F
temperature range or colder, the outdoor coil
temperature is 32°F or below. This coil temperature is
sensed by the coil temperature sensor mounted near the
bottom of the outdoor coil. Once coil temperature
reaches 30°F or below, the coil temperature sensor
sends a signal to the control logic of the heat pump
control and the defrost timer will start.
After 60 minutes at 30°F or below, the heat pump
control will place the system in the defrost mode.
During the defrost mode, the refrigerant cycle switches
back to the cooling cycle, the outdoor motor stops,
electric heaters are energized, and hot gas passing
through the outdoor coil melts any accumulated frost.
When the temperature rises to approximately 57°F, the
coil temperature sensor will send a signal to the heat
pump control which will return the system to heating
operations automatically.
If some abnormal or temporary condition such as a high
wind causes the heat pump to have a prolonged defrost
cycle, the heat pump control will restore the system to
heating operation automatically after 10 minutes.
The heat pump defrost control board has an option of
30, 60 or 90-minute settings. All models are shipped
from the factory on the 60-minute pin. If special
circumstances require a change to another time, remove
the wire from the 60-minute terminal and reconnect to
the desired terminal. The manufacturer's
recommendation is for 60-minute defrost cycles. Refer
to Figure 14.
There is a cycle speed up jumper on the control. This
can be used to reduce the time between defrost cycle
operation without waiting for time to elapse.
Use a small screwdriver or other metallic object, or
another 1/4 inch QC, to short between the SPEEDUP
terminals to accelerate the HPC timer and initiate
defrost.
Be careful not to touch any other terminals with the
instrument used to short the SPEEDUP terminals. It
may take up to 10 seconds with the SPEEDUP
terminals shorted for the speedup to be completed and
the defrost cycle to start.
As soon as the defrost cycle kicks in remove the
shorting instrument from the SPEEDUP terminals.
Otherwise the timing will remain accelerated and run
through the 1-minute minimum defrost length sequence
in a matter of seconds and will automatically terminate
the defrost sequence.
There is an initiate defrost jumper (sen jump) on the
control that can be used at any outdoor ambient during
the heating cycle to simulate a 0° coil temperature.
This can be used to check defrost operation of the unit
without waiting for the outdoor ambient to fall into the
defrost region.
By placing a jumper across the SEN JMP terminals (a
1/4 inch QC terminal works best) the defrost sensor
mounted on the outdoor coil is shunted out and will
activate the timing circuit. This permits the defrost
cycle to be checked out in warmer weather conditions
without the outdoor temperature having to fall into the
defrost region.
In order to terminate the defrost test the SEN JMP
jumper must be removed. If left in place too long the
compressor could stop due to the high pressure control
opening because of high pressure condition created by
operating in the cooling mode with outdoor fan off.
Pressure will rise fairly fast as
there is likely no actual frost on the
outdoor coil in this artificial test
condition.
There is also a 5-minute compressor
time delay function built into the
HPC. This is to protect the
compressor from short cycling
conditions. In some instances it is
helpful to the service technician to
override or speed up this timing
period, and shorting out the
SPEEDUP terminals for a few
seconds can do this.
FIGURE 14
DEFROST CONTROL BOARD