American Standard WKD063C Owner's manual

WK-IOM-1
Library Service Literature
Product Section Unitary
Product Rooftop AC – Lt. Comm. SZ
Model WK
Literature Type Installation/ Oper/ Maint
Sequence 1
Date November 2000
File No. SV-UN-RT-WK-IOM-1 11/00
Supersedes New
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
IMPORTANT NOTE: All phases of this installation must comply with the NATIONAL, STATE & LOCAL CODES. These
units are equipped with an electronic unitary 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.
Models: (50 Hz)
WK(D,H)063C
WK(D,H)073C
INSTALLATION
OPERATION
MAINTENANCE
Customer Property — Contains wiring, service,
and operation information. Please retain.
Packaged Heat Pump
063C - 073C

2
IMPORTANT: Read the entire manual before be-
ginning installation procedures.
Bodily injury can re-
sult from high voltage electrical components or
fast moving fan drives. For protection from these
inherent hazards during installation and servicing,
the electrical supply must be disconnected. If op-
erating checks must be performed with the unit
operating, it is the technician’s responsibility to
recognize these hazards and proceed safely.
IMPORTANT: All power legs may not be broken
by contactors. See wiring diagram on unit control
box cover. Before starting the compressor, the
crankcase heaters should be energized for eight
hours.
Read this manual carefully before attempting to install, op-
erate or perform maintenance on this unit. Installation and
maintenance must be performed by qualified service tech-
nicians except where noted.
Note: “Warnings” and “Cautions” appear at appro-
priate 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.
Model WK heating/cooling units are designed for outdoor
mounting with a vertical condenser discharge. They can
be located either at ground level or on a roof. Each unit
contains an operating charge of refrigerant as shipped.
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 the unit nameplate to determine if the unit volt-
age is correct for the application. Determine if adequate
electrical power is available. Refer to the application
specifications.
3. Check to be sure the refrigerant charge has been re-
tained during shipment. Access to 1/4" flare pressure
taps may be gained by removing compressor compart-
ment access panel.
Overall unit dimensional data for a cooling only unit is illus-
trated in Figure 1.
Table of Contents
Inspection...................................................................... 2
Module Names .............................................................. 3
Unit Features ................................................................ 3
Self-test/Auto-configuration........................................... 3
Cooling Minimum ON/OFF times .................................. 3
Zone sensor operation .................................................. 3
Unit Mode...................................................................... 3
Fan Settings .................................................................. 3
Optional Remote Panel Zone Sensors
Indicator Lights.............................................................. 3
Dimensional Data.......................................................... 4
Downflow Unit ............................................................... 4
Horizontal Unit .............................................................. 5
Curb Dimensions .......................................................... 5
Installation ..................................................................... 7
Location and Recommendations .................................. 7
Unit Support .................................................................. 7
Condensate Drain Piping .............................................. 8
Filter Installation ............................................................ 8
Electrical Connections .................................................. 8
Control Wiring (Class II) .............................................. 10
Field Installed DC Control Wiring ................................ 13
Zone Temperature Sensor Terminal Strip ................... 13
Emergency Shut Down ............................................... 13
Compressor Disable ................................................... 13
Duct Mounted Supply Air Sensor (SAS) ..................... 14
Start-Up....................................................................... 14
Test Mode Procedure.................................................. 14
Step Test Mode ........................................................... 14
Auto Test Mode ........................................................... 15
Test Mode Table .......................................................... 15
Resistance Test Mode................................................. 15
Evaporator Fan Adjustment ........................................ 16
Starting the Unit in the Heating Mode ......................... 16
Starting The Unit In The Cooling Mode....................... 17
Evaporator Defrost ...................................................... 17
Demand Defrost .......................................................... 17
Final Installation Checklist & Maintenance ................. 18
Routine Maintenance By Owner ................................. 18
Air Filters ..................................................................... 18
Condenser Coil ........................................................... 18
Maintenance Performed by Serviceman -
Cooling Season........................................................... 18
Maintenance Performed By Serviceman -
Heating Season .......................................................... 18

3
Module Names
UCP
Packaged Rooftop Units are controlled by a microelec-
tronic control system that is referred to as "Unit Control
Processor" (UCP). The acronym UCP is used extensively
throughout this document when referring to the control
system network. The "Unit Control Processor" (standard
component) and one of the zone sensor modules makes
up the minimum system configuration requirement.
ZSM
Zone Sensor Module (accessory component). Replaces
thermostat, provides operator controls and the zone tem-
perature sensor for the UCP.Acomplete line of ZSMs is
available with various combinations of features.A zone
sensor module, or a CTI is required for each system.
UEM
Unitary Economizer Module (standard component on
economizer accessory). This module provides the hard-
ware necessary to connect the economizer accessory to
theUCP.
TCI
TCI Communications Interface (accessory component).
This interface module is required to connect the system to
an ICS BUILDING MANAGEMENT SYSTEM. i.e. - Tracer
or Tracker.
CTI
Conventional Thermostat Interface (accessory compo-
nent). This module can be used in special applications that
require the installation of select electro-mechanical ther-
mostats 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. This means there is no
field configuration necessary when replacing the UCP, with
exception of the zone comfort switch settings.
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 fail-
ure), the 3 minutes minimum OFF time is enforced to pre-
vent short cycling a compressor.
Zone sensor operation
The zone sensors provide the user controls and zone tem-
perature sensing function. The operator controls are as fol-
lows:
Unit Mode
Heat - Heat functions only enabled
Auto - Auto-changeover between cooling mode and heat-
ing mode as required by zone load. (On some models)
Off - No heating or cooling functions
Cool - Cooling functions only (including economizing) en-
abled
Fan Settings
Fan Auto - Fan runs only when heating or cooling func-
tions are required
Fan On - Fan runs at all times. This is the setting used
when minimum ventilation is required. When the fan is
running, the economizer dampers will be open to at
least minimum position.
Optional Remote Panel Zone Sensors
Indicator Lights
SYS On
Indicates that power is applied to the unit and the UCP is
functioning correctly. This indicator will flash at a 1 second
rate to indicate operation in one of the test modes.
Heat
Indicates that at least one stage of heat is ON. This indica-
tor 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
second rate to indicate a cool failure. Sources of cool fail-
ure include high pressure controls if present and zone sen-
sor failures.
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.

4
Dimensional Data
Figure 1
Unit Dimensions - mm
UNITS ABCDEFGHJ
WK*063 & 073 889 1259 2213 1064 152 156 213 98 60
* Downflow and/or Horizontal
Downflow Unit
Top View Showing Duct Openings in the Base - mm
UNITS ABCDEFG
WK*063 - 073 895 386 572 329 83 86 1013

5
Dimensional Data (Continued)
Figure 1 (Continued)
Horizontal Unit
Rear View Showing Duct Openings For Horizontal Air Flow - mm
UNITS ABCDEF
WK*063 - 073 406 408 511 60 137 686
Figure 2
Curb Dimensions - mm
UNITS ABCDD*EE*FGHJKLM
WK*063 - 073 2064 1170 356 365 556 438 551 464 1076 25 46 919 2073 1178
* Dimensions when round ductwork is used.

6
Dimensional Data (Continued)
Figure 2 (Continued)
Field Fabricated Duct Dimensions - mm
UNITS ABCDEFGHJK
TK*063 - 073 1048 38 905 429 1124 575 1124 581 457 457

7
Installation
When installing the unit, it must be level to insure proper
condensate flow from the unit drain pan.
Slab Mount
“For ground level installation, the unit base should be ad-
equately supported and hold the unit near level. The instal-
lation must meet the guidelines set forth in local codes.”
Table 1
Corner Weights & Center of Gravity - mm
Unit Net
Models Weight Length Width ABCD
WK*063C 256 965 533 102 79 59 73
WK*073C 327 965 508 113 82 60 72
* Downflow or Horizontal
Corner Wts. (mm)
Note: Corner weights are given for information
only. Unit is to be supported continuously by curb
or equivalent frame support.
Ductwork
Attaching Downflow Ductwork to The Roof Curb
Supply and return air flanges are provided on the roof curb
for easy duct installation. All duct work must be run and at-
tached to the curb before the unit is set into place. See
Figure 2 for duct connections.
Ductwork construction guidelines:
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 two feet from the unit, to minimize noise
and resistance.
Location and Recommendations
Unit Support
If unit is to be roof mounted check building codes for
weight distribution requirements. Refer to accessory roof
curb mounting instructions.
Location and Clearances
Installation of unit should conform to local and national
building codes.
Select a location that will permit unobstructed airflow into
the condenser coil and away from the fan discharge and
permit unobstructed service access into the compressor
compartment. Suggested airflow clearances and service
clearances are given in Figure 2.
Placing and Rigging
Rig the unit using either belt or cable slings. The sling eye-
let must be placed through the lifting holes in the base rail
of the unit. The point where the slings meet the lifting eye-
let should be at least 1.8mm (6 feet) above the unit. Use
spreader bars to prevent excessive pressure on the top of
the unit during lifting. Figure 3 shows the unit center of
gravity and rigging recommendations.
IMPORTANT: The use of “spreader bars” is re-
quired when hoisting the unit (prevents damage to
sides and top). Top crating can be used as
spreader bars.
Figure 3
Roof Mounted Units
Downflow units should be mounted on a roof curb when
possible. When installing the unit on the roof curb, follow
the installation 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 in-
stalled 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 2.

8
Installation (Continued)
Filter Installation
Access to the filters is made by removing the evaporator
fan access panel. Each downflow unit ships with 50mm
(one-inch) filters, as determined by unit size. To modify the
unit filter racks to accept two 50mm (one-inch) filters, the L-
shaped angles (which are held in place with screws and
formed tabs) on the racks must be rotated. Remove the
screws, turn the angles 90 degrees, and reinstall the
screws. Refer to the unit Service Facts for filter require-
ments.
Important: Do not operate unit without filters in
place.
Electrical Connections
Check the unit nameplate for the required supply voltage.
Determine if adequate electrical power is available. Refer
to application specifications.
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 weatherproof 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.
Power Wiring
The power supply lines must be run in approved conduit to
the disconnect, and in the bottom of the unit control box.
Provide strain relief for all conduit with suitable connectors.
(Wiring instructions change when electric heaters are used,
See Figure 5 for power entry guide.
Attaching Horizontal Ductwork to The Unit
All conditioned air ductwork should be insulated to mini-
mize heating and cooling duct losses. Use minimum of
50mm (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. The flexible connection
must be indoors and molded out of heavy canvas.
Note: Do not draw the canvas taut between the
solid ducts. See Figure 1 for duct connections.
Condensate Drain Piping
A 3/4 inch male PVC condensate drain connection is pro-
vided on the opposite side of the unit from the evaporator
section access panel on downflow units. On horizontal
units, the condensate drain connection is located on the
corner of the unit next to the evaporator section access
panel. See Figure 1. A trap should be installed and filled
with water before starting the unit to avoid air from being
drawn through. Follow local codes and standard piping
practices when running the drain line. Pitch the line down-
ward, away from the unit, and avoid long horizontal runs.
See Figure 4.
Do not use reducing fittings in the drain lines. The con-
densate drain must be:
1. Made of 3/4" pipe size.
2. Pitched 2.1 mm per meter (1/4" per foot) to provide
free drainage to convenient drain system.
3. Trapped
4. Must not be connected to closed drain system.
Figure 4

9
Figure 5
Power Entry Guide
Important: Holes are provided for low-voltage and high-voltage wiring. It is not necessary to punch any new
holes in either the interior or exterior unit panels. If new holes are punched, performance will be adversely
affected unless they are resealed to be both air- and watertight.
Figure 5A
Typical Field Wiring Diagram

10
Electrical Connections (Continued)
Provide flexible conduit supports whenever vibration trans-
mission may cause a noise problem within the building
structure.
See Figure 5A for high voltage wiring connections. Insure
all connections are made tight.
Note: For branch circuit wiring (main power sup-
ply to unit disconnect), wire size for the length of
run should be determined using the circuit am-
pacity found on the unit nameplate.
For more than 3 conductors in a raceway or cable, see the
N.E.C. for de-rating the ampacity of each conductor.
GROUNDING: THE UNIT MUST BE ELECTRICALLY
GROUNDED IN ACCORDANCE WITH LOCAL AND NA-
TIONAL CODES.
Control Wiring
Some models have a 24 voltage transformer with an inte-
gral circuit breaker. If the breaker trips, open unit discon-
nect before attempting to reset breaker. Models with a
50VA transformer do not have this circuit breaker.
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 access 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: The unit 24 volt transformer must not
be used to power Field Installed Accessories
(FIA), except for the ones that are factory sup-
ported.