American Standard WK 100 Series Owner's manual

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WK-IOM-2
Library Service Literature
Product Section Unitary
Product Rooftop Lt. Comm.
Model WK
Literature Type Installation/ Oper/ Maint
Sequence 2
Date November 2000
File No. SV-UN-RT-WK-IOM-2 11/00
Supersedes New
Packaged Heat Pump
100 - 200 Models
INSTALLATION
OPERATION
MAINTENANCE
Customer Property — Contains wiring, service,
and operation information. Please retain.
Models: (50 Hz)
WK*100-125
WK*155-200
IMPORTANT NOTE: All phases of this installation must comply with the NATIONAL, STATE & LOCAL CODES.
These units are equipped with an electronic unit control processor, (UCP) that provides service functions which are
significantly different from conventional units. Refer to the TEST MODES and START-UP PROCEDURES before
attempting to operate or perform maintenance on this unit.
Since the manufacturer has a policy of continuous product
improvement, it reserves the right to change specifications and design
without notice. The installation and servicing of the equipment referred
to in this booklet should be done by qualified, experienced technicians.
© American Standard Inc. 2000

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Read this manual carefully before attempting to install, oper-
ate or perform maintenance on this unit. Installation and main-
tenance must be performed by qualified service technicians
except where noted.
Bodily injury can result
from high voltage electrical components and fast
moving fan drives. For protection from these inherent
hazards during installation and servicing, the
electrical supply must be turned off. If operating
checks must be performed with the unit operating, it
is the technician’s responsibility to recognize these
hazards and proceed safely.
All power legs to the
electrical components may not be broken by
contactors. See the wiring diagram on the unit control
box cover.
Before starting the compressor, the crankcase heaters should
be energized for eight hours.
Attaching Downflow Ductwork to Roof Curb ............. 9
Filter Installation ........................................................ 9
Evaporator Fan Adjustment ....................................... 9
Interconnecting Diagram ......................................... 12
Wire Connection Guide ........................................... 14
Pre-Start Quick Check List ...................................... 14
Power-up Initialization ............................................. 15
Unitary Control Processor (UCP) ............................ 15
Switch Settings for Cycle Timing ............................. 15
Defrost Module Test & Operation ............................ 16
Final Installation Checklist ....................................... 16
Inspection .................................................................. 2
Module Names .......................................................... 3
Unit Features ............................................................. 3
ZSM Mode ................................................................. 3
Auto Test Mode.......................................................... 4
Resistance Test Mode ............................................... 4
Unit Dimensions ........................................................ 5
Curb Dimensions ....................................................... 6
Installation ................................................................. 7
Unit Support .............................................................. 7
Location and Clearances........................................... 7
Placing and Rigging .................................................. 7
Table of Contents
Note: “Warnings” and “Cautions” appear at
appropriate places in this manual. Your personal
safety and the proper operation of this machine
require that you follow them carefully. The
manufacturer assumes no liability for installations or
servicing performed by unqualified personnel.
Inspection
1. Check for damage after unit is unloaded. Report promptly,
to the carrier, any damage found to unit. Do not drop unit.
2. Check unit nameplate to determine if unit is correct for ap-
plication intended. Power supply must be adequate for the unit
and all accessories.
3. Check to be sure the refrigerant charge has been retained
during shipment. Access to 1/4" flare pressure taps may be
gained by removing compressor compartment access panel.

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MODULE NAMES
UCP -Unitary Control Processor (standard component)
This is the heart of the system. The computer program
resides in this module. The minimum configuration will
include the UCP and one of the zone sensor modules
ZSM -Zone Sensor Module (accessory component)
Replaces thermostat, provides operator controls and the
zone temperature sensor for the UCP.Acomplete line of
ZSMs is available with various combinations of features.
A zone sensor module, or a CTI and generic control is
required for each system.
UEM - Unitary Economizer Module (standard component
on economizer accessory). This module provides the
hardware necessary to connect the economizer
accessory to the UCP.
TCI - Communication Interface. This interface is required
to connect the system to an ICS BUILDING
MANAGEMENT, i.e. - Tracker or Tracer. system.
CTI - Conventional Thermostat Interface (accessory
component.) This module can be used in special
applications that require the installation of select electro-
mechanical thermostats to interface with the UCP, instead
of using a zone sensor module (ZSM)
UNIT FEATURES
Self-test/Auto-configuration
At power-up, the system will perform a series of tests to verify
correct operation and configure itself automatically, based on
the unit wiring harness.
Cooling Minimum ON/OFF times
To enhance compressor reliability, a minimum of 3 minutes
ON/OFF time has been implemented in the software. Any time
power is applied or re-applied (e.g. after a power failure), the 3
minutes minimum OFF time is enforced to prevent short cy-
cling a compressor.
Lead-Lag (Cooling Mode Only)
A selectable configuration within the UCP which alternates the
starting of the compressors between the two refrigeration cir-
cuits. To enable the Lead/Lag function, cut wire 52F (PR)
which is connected to terminal J1-7 at the UCP. Refer to the
unit wiring diagram. Each time the request for cooling is satis-
fied, the designated lead compressor switches. Upon Power-
up Initialization, the control will default to the number one com-
pressor. When a Conventional Thermostat Interface (CTI) is
used, Lead/Lag is functional except during the test mode.
Zone Temperature Sensor
The zone temperature sensor provides the zone temperature
sensing function to the UCP.
ZSM MODE
HEAT - Heat functions only enabled.
AUTO - Auto-changeover between Cooling mode and
Heating mode as required by zone load (on some
models).
OFF - No heating or cooling functions
COOL - Cooling functions only, including economizer function
enabled.
FAN SETTINGS
FAN AUTO - Fan is enabled only when heating or cool
ing functions are required.
FAN ON - Fan is enabled at all times. This setting is
used when air circulation is required.
Option Remote Panel Zone Sensors
Indicator Lights
SYS-ON
Indicates that power is applied to the unit and the UCP is func-
tioning correctly. This indicator will flash at a 1 second rate to
indicate operation of one of the test modes.
HEAT
Indicates that at least one stage of heat is ON. This indicator
will flash at a 1 second rate to indicate a heat failure .
COOL
Indicates that cooling is active. This could be economizing
and/or compressor cooling. This indicator will flash at a 1 sec-
ond rate to indicate a cool failure. Sources of cool failure in-
clude high pressure controls if present and zone sensor fail-
ures.
SERVICE
Indicates that a problem exists in the supply air stream. Could
be dirty filters, broken drive belt or other functions depending
on what sensors or switches are installed on the fan/filter
status input.

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Test Mode Table
Step Mode Fan Econ C1 C2 Heat 1 Heat 2 Heat 3 Defrost Em Heat
1 Fan On On Min Off Off Off Off Off Off Off
2* Econ On Open Off Off Off Off Off Off Off
3 Cool 1 On Min On Off Off Off Off Off Off
4 Cool 2 On Min On On Off Off Off Off Off
5 Heat1 On Min On On On Off Off Off Off
6* Heat 2 On Min On On On On Off Off Off
7* Heat 3 On Min On On On On On Off Off
8** Defrost On Min On On Off On On On Off
9** Em Heat On Min Off Off Off On On Off On
* With Optional Accessory ** With Heat Pump
Note: Steps for optional accessories and modes not present in unit, will be skipped.
Resistance Valves Chart
STEP MODE Ohms
1 FAN ON 2.2K
2* ECONOMIZER 3.3K
3 COOL 1 4.7K
4 COOL 2 6.8K
5 HEAT 1 10K
6* HEAT 2 15K * With Optional Accessory
7* HEAT 3 22K ** With Heat Pumps
8** DEFROST 33K Note: Steps 7,8 & 9 are not applicable
9** EM HEAT 47K on Electric/Electric or Gas Units
TEST MODE PROCEDURE
Operating the unit from the roof using the test mode.
When operating the unit in
the test mode, the evaporator access panel and the
control box cover, must be closed. Failure to ensure
that the evaporator access panel and control box
cover is in place could result in severe personal
injury or death
The Unitary Control Processor (UCP) has a red indicator light
in the lower left corner. When power is applied to the unit the
light will glow if the UCP is functioning correctly. If the system
is placed in the test mode the light will blink continuously.
Note: The control box cover has a small peep hole,
located in the lower left hand corner. The red
indicator light on the UCP can be seen through this
peep hole. Do not remove the control box cover while
the unit power is connected.
Step Test Mode
The step test mode is initiated by shorting across the “TEST”
terminals, marked test 1 and test 2 on the unit’s low voltage
terminal strip (LTB), for two (2) to three (3) seconds and then
removing the short.
When the test mode is initiated, the light on the UCP will blink
and the system will begin the first test step, and turn on the in-
door fan. (See test mode table)
To continue to the next step, reapply the short across the test
terminals for 2 to 3 seconds.
The unit may be left in any test step for up to one hour. If al-
lowed to remain in any test step for more than one hour, the
test mode will terminate and control will revert to the zone sen-
sor. As you continue to apply and remove the short across the
test terminals, the unit will move through the steps according
to the table below.
To terminate the test mode, cycle the unit power at the unit
disconnect or continue stepping through the modes until the
UCP’s indicator light glows constantly.
Auto Test Mode
—The auto test mode is initiated by installing a jumper be-
tween terminals marked TEST 1 and TEST 2 on the LTB.
The unit will start in step 1 and cycle through the test steps
one time, changing every 30 seconds.
—When the test mode is initiated, the light on the UCP will
blink and the system will begin the first test step, and turn
on the indoor fan. (See test mode table)
—At the end of the auto test mode, the indicator light will glow
constantly and control will revert to the zone sensor.
—The unit can be left in any one of the test steps, by remov-
ing the jumper. It will remain in this step for up to one hour.
If allowed to remain in any test step for more than one hour,
the test mode will terminate and control will revert to the
zone sensor.
— To terminate the test mode, cycle the unit power at the unit
disconnect.
Resistance Test Mode
The resistance test mode is Initiated by applying the appropri-
ate resistance value across the “Test” terminals marked TEST
1 and TEST 2 on the LTB.
—When the test mode is initiated, the light on the UCP will
blink and the system will begin the test step selected by the
resistance being applied across the test terminals. (See test
mode table)
—The resistance values are indicated in the Resistance Value
Chart below.
—After selecting the desired test step, and applying the appro-
priate resistance across the test terminals, the unit will start.
—The unit can be left in this step for up to one hour. If allowed
to remain in any test step for more than one hour, the test
mode will terminate and control will revert to the zone sensor.
—To terminate the test mode, remove the resistance, and
cycle the unit power at the unit disconnect.

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HORIZONTAL UNIT
REAR VIEW SHOWING DUCT OPENINGS
FOR HORIZONTAL AIR FLOW - mm
UNITS A B C D E F
WKH100 571 457 437 51 100 1053
WKH125, 155 673 497 624 51 100 1080
WKH200 673 611 700 51 100 1180
DOWNFLOW UNIT
TOP VIEW SHOWING DUCT OPENINGS IN THE BASE - mm
UNITS A B C D E
WKD100 570 368 449 1312 1199
WKD125, 155 672 572 475 1586 1389
WKD200 672 730 506 1938 1745
Dimensional Data
Unit Dimensions - mm
Units ABCDEFGHJK
WK* 100 1608 2380 20 1245 726 56 213 1000 173 51
WK* 125, 155 1798 2710 20 1273 744 68 213 1229 168 51
WK* 200 2154 3107 20 1372 843 69 226 1422 173 76
* Downflow or Horizontal

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Figure 1 - Curb Dimensions - mm
UNITS A B C D E F G H J K L M N P
WKD100 1502 1408 46 486 251 622 2259 1509 2267 51 357 25 205 1205
WKD125, 155 1692 1600 46 530 435 724 2588 1702 2597 51 357 25 191 1410
WKD200 2048 1956 46 565 591 725 2969 2057 2977 51 357 25 191 1765

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INSTALLATION
Location and Recommendations
Unit Support
If unit is to be roof mounted check building codes for weight
distribution requirements. Refer to accessory roof curb mount-
ing instructions. Check unit nameplate for supply voltage re-
quired. Determine if adequate electrical power is available.
Refer to specification sheet.
Location and Clearances
Installation of unit should conform to local and national build-
ing codes.
Select a location that will permit unobstructed airflow into the
condenser coil and away from the fan discharge. Suggested
airflow clearances and service clearances are given in
Figure 1.
Placing and Rigging
Note : Before attempting to rig the unit, remove the
fork lift pockets located on the condenser end of the
unit.
Rig the unit using either belt or cable slings. The sling eyelet
must be placed through the lifting holes in the base rail of the
unit. The point where the slings meet the lifting eyelet should
be at least 6 feet above the unit. Use spreader bars to prevent
excessive pressure on the top of the unit during lifting. Figure
2 shows the unit center of gravity.
IMPORTANT: The use of “spreader bars” is required
when hoisting the unit (prevents damage to sides and
top). Top crating can be used as spreader bars.
Figure 2
Mounting Unit on Roof
Downflow units should be mounted on a roof curb when pos-
sible. When installing the unit on the roof curb, follow the in-
stallation instructions accompanying the roof curb kit. On new
roofs, the curb should be welded directly to the roof deck. For
existing construction, nailers must be installed under the curb
if welding is not possible. Be sure to attach the downflow
ductwork to the curb before setting unit in place. See Figure
3A or 3B. Refer to the curb installation instructions to insure
the unit will be level.
When installing the unit, it must be level to insure proper con-
densate flow from the unit drain pan. The maximum pitch of
the unit down from the condensate drain of the unit is 0.5 mm
per meter (1/16 inch per foot).
Slab Mount
For ground level installation, the unit base should be ad-
equately supported and hold the unit near level. The installa-
tion must meet the guidelines set forth in local codes.
Table 1
Corner weights & Center of Gravity
Unit Net
DimensionsWeightABCDLengthWidth
WK*100B 536 183 140 92 120 1041 635
WK*125B 625 218 159 105 144 1143 711
WK*155B 642 228 162 105 147 1143 711
WK*200B 871 291 226 155 199 1346 889
* Downflow or Horizontal
Corner Weights (kg)
(See Note 1) Center of Gravity (mm)

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Note: Corner weights are given for information only. Unit is to be supported continuously by curb or equivalent
frame support.
Duct Dimensions - mm
UNITS ABCDEFG
WK*100 1318 411 1130 567 25 357 189
WK*125, 155 1510 454 1334 643 25 357 189
WK*200 1865 491 1689 668 25 357 189
* G Dimension represents the distance from the top fo the curb to the duct flange.
Figure 3

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Figure 4
Filter Installation
To gain access to filters, remove the evaporator fan access
panel. Each unit ships with 2 inch filters. Number and size of fil-
ters is determined by size and configuration of the unit. Refer to
the unit “Service Facts” for filter requirements.
Note: On WKD100 and WKH200 units, there is an
installation instruction label on the end of the filter rack
which provides instructions on how to replace the top
filters.
Evaporator Fan Adjustment
Use the following procedure to determine the proper adjustment
of the evaporator fan sheaves for a specific application.
1. Determine total system external static pressure (in inches wa-
ter column) with accessories installed. To accomplish this:
a. Obtain the design airflow rate and the design external
static pressure drop through the distribution system. Your
sales representative or the design engineer can provide you
with these values.
b. Using the table from unit Service Facts, add static
pressure drop of the accessories installed on the unit.
c. Add the total accessory static pressure drop (from step
1b) to the design external static pressure. The sum of these
two values is the total system external static pressure.
2 . Use the table(s) in the Service Facts to find the external static
pressure (in inches water column) that most closely approxi-
mates total system external static pressure. Then locate the
appropriate airflow rate (in m3/n (cfm) for your unit. The value
obtained represents the Kw brake horsepower for the evapo-
rator fan motor and the fan RPM.
Important: Fan Kw Break Horsepower (BHP) listed in
the Table is the percentage range of nameplate
amperage the motors will safely work within before and
oversized motor is required.
3. Adjust the variable pitch pulley to increase or decrease the
fan RPM as required. See Figure 5.
Ductwork
Attaching Downflow Ductwork to Roof Curb
Supply and return openings have curb flanges provided for
easy duct installation.
Note: Ductwork sleeves must be attached to the
curb flanges before the unit is set into place. See
Figure 3A and 3B for duct connections and
dimensions.
Guidelines for ductwork construction:
— Connections to the unit should be made with three-inch
canvas connectors to minimize noise and vibration trans-
mission.
— Elbows with turning vanes or splitters are recommended to
minimize air noise and resistance.
— The first elbow in the ductwork leaving the unit should be
no closer than 610 mm (two feet) from the unit, to mini-
mize noise and resistance.
Attaching Horizontal Ductwork to Unit
— All conditioned air ductwork should be insulated to mini-
mize heating and cooling duct losses. Use minimum of 50
mm (2") of insulation with a vapor barrier. The outside
ductwork must be weather proofed between the unit and
the building.
— When attaching ductwork to a horizontal unit, provide a
flexible water tight connection to prevent noise transmis-
sion from the unit to the ducts.
Note: Do not draw the canvas connectors taut
between the unit and ducts. See dimensional data
for duct connections.
Condensate Drain Piping
A 1 inch NPT female condensate drain connection is pro-
vided on all units.
Follow local codes and standard piping practices when run-
ning the drain line. Install a trap and be sure to fill with water
before starting the unit. Pitch the line downward, away from
the unit; avoid long, level, horizontal runs. Refer to Figure 4.

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Power Wiring
The power supply lines must be run in weather-tight conduit to the
disconnect, and into the bottom of the unit control box. Provide
strain relief for all conduit with suitable connectors.
Provide flexible conduit supports whenever vibration transmission
may cause a noise problem within the building structure.
Insure all connections are made tight. (See Figure 6)
Note: For branch circuit wiring (main power supply to
unit disconnect), Wire size for the length of run should be
determined using the circuit ampacity found on the unit
nameplate and the N.E.C..
For more than 3 current carrying conductors in a raceway or cable,
for de-rating the ampacity of each conductor.
GROUNDING: THE UNIT MUST BE ELECTRICALLY
GROUNDED IN ACCORDANCE WITH LOCAL AND NATIONAL
CODES.
Control Wiring (Class II)
Note about 24 Volt Transformers:
Units have intergal circuit breakers in their low voltage transform-
ers. If the breaker trips, be sure to open the unit disconnect before
attempting to reset the breaker.
Some earlier model units have a replaceable fuse mounted in the
transformer. An extra fuse is taped down near the transformer. To
use this replacement fuse, remove the old one by pushing in and
turning counter-clockwise 1/4 turn, then pull it out. To insert the
new fuse, push in and turn clockwise until it stops.
CAUTION: Do not replace with a fuse of greater ampacity
than 3.5 amps.
Open and lock unit
disconnect. Failure to do so could result in severe
personal injury or death due to electrical shock.
Remove compressor access panel and control box panel to ac-
cess transformer. Reset by pressing in on the black reset button
located on the left side of the transformer.
Replace all panels before restoring power to the unit.
Important Note: The unit 24 volt transformer must not be
used to power Field Installed Accessories (FIA), except
for the ones that are factory supported.
Figure 5
Typical fan, motor, and sheave assembly
TO INCREASE M3/h CFM
Loosen the pulley adjustment set screw and turn sheave
clockwise
TO DECREASE M3/hCFM
Loosen the pulley adjustment set screw and turn sheave
counter-clockwise
TO INCREASE BELT TENSION
Loosen the nut (next to the idler sheave) that secures the
sheave in place. With a wrench, apply pressure clockwise
on the outside nut (round headed one), until tension de-
sired is reached. While holding pressure with the tension
nut, retighten the nut next to the idler sheave.
Electrical Connections
Electrical wiring and grounding must be installed in accor-
dance with local and national codes.
Electrical Power
It is important that proper electrical power is available for
the unit. Voltage variation should remain within the limits
stamped on the nameplate.
Power Entry
Holes are provided for low-voltage and high-voltage wiring.
It is not necessary to punch any new holes in either the in-
terior or exterior unit panels. If new holes are punched, per-
formance will be adversely affected unless they are re-
sealed to be both air- and watertight.
Disconnect Switch
Provide an approved weather-proof disconnect either on
the side of unit or within close proximity.
Over Current Protection
The branch circuit feeding the unit must be protected as
shown on the unit rating plate.