American Standard YC 102-301 Series Owner's manual

1
YC-IOM-4G
18-EB60D11-7
Library Service Literature
Product Section Unitary
Product Rooftop Lt. Comm.
Model YC
Literature Type Installation/ Oper/ Maint
Sequence 4G
Date August 1998
File No. SV-UN-RT-YC-IOM-4G 8/98
Supersedes YC-IOM-4F
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. 1998
Packaged Gas/Electric
8-1/2 thru 25 Ton
INSTALLATION
OPERATION
MAINTENANCE
Customer Property — Contains wiring, service,
and operation information. Please retain.
Models: (60 Hz) (50 Hz)
YC*102-301 YC*085-250
IMPORTANT NOTE: All phases of this installation must comply with the NATIONAL, STATE & LOCAL CODES. In
additiontolocalcodes,theinstallationmustconformwithNationalElectricCode-ANSI/NFPANO.70LATESTREVISION.
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.

2
.
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, fast moving
fan drives and combustible gas. For protection from
these inherent hazards during installation and
servicing, the electrical supply must be disconnected
and the main gas valve 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.
IMPORTANT: This unit, as shipped from the factory,
is designed to use natural gas only. Do not connect
gas piping to the unit until a line pressure test has
been completed. Pressure in excess of 14 inches
water column (1/2 PSIG) may damage the gas valve
resulting in an unsafe condition.
All power legs to the
electrical components may not be broken by
contactors. See the wiring diagram on the unit control
box cover.
.
Pipe Delivery Schedule ........................................... 11
Gas Piping Schematic ............................................. 11
Manifold Pressure ................................................... 10
Filter Installation ...................................................... 10
Evaporator Fan Adjustment ..................................... 12
Interconnecting Diagram ......................................... 14
Compressors ........................................................... 15
Pre-Start Quick Check List ...................................... 15
Power-up Initialization ............................................. 16
Unitary Control Processor (UCP) ............................ 16
Switch Settings for Cycle Timing ............................. 16
Final Installation Checklist ....................................... 18
Table of Contents
Inspection .................................................................. 2
Module Names .......................................................... 3
Unit Features ............................................................. 3
ZSM Mode ................................................................. 3
ReturnAir Smoke Detector........................................ 4
Auto Test Mode.......................................................... 5
Resistance Test Mode ............................................... 5
Unit Dimensions ........................................................ 6
Curb Dimensions ....................................................... 7
Installation ................................................................. 8
Unit Support .............................................................. 8
Location and Clearances........................................... 8
Placing and Rigging .................................................. 8
Attaching Downflow Ductwork to Roof Curb ........... 10
UNIT CONTAINS AN HCFC (R-22) REFRIGERANT
Section 608 paragraph C of the 1990 Clean Air Act states: Effective July 1, 1992 it shall be unlawful for any person,
in the course of maintaining, servicing, repairing, or disposing of an air conditioning system, to knowingly vent or
release any CFC or HCFC refrigerant. Minimal releases (air purges of refrigerant hoses) associated with good
faith attempts to recapture or recycle are exempt from the ban on venting.
Before starting the compressor, the crankcase heaters should
be energized for eight hours.
Exception - Circuit #1 on 181 and 211 units and both circuits
on the 200, 240 thru 301 units are not equipped with crank-
case heaters.
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.

3
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 (BAYCTHI001) 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 (BAYCTHI001
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
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 disignated lead compressor switches. Upon Powerup
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.
Ignition Control Module
There are two LED's located in the Ignition Control Module
that monitor the operating status of the heater during the vari-
ous operating states and sets diagnostics should a failure oc-
cur.
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
cooling
functions are required.
FAN ON - Fan is enabled at all times. This setting is
used when minimum ventilation 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 when limit
TCO1 and/or TCO2 has tripped.
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.

4
Return Air Smoke Detector
Important: If this unit is equipped with an economizer,
it will be necessary for the installer to complete the
hook-up of the return air smoke detector. Refer to the
installation instructions for the return air smoke
detector provided in the literature package for the
step-by-step procedure to complete this hook-up.
Important: The return air smoke detector is designed
to shut off the unit if smoke is sensed in the return air
stream. This function is performed by sampling the
airflow intering the unit at the return air opening.
Follow the instructions provided below to assure that
the airflow through the unit is sufficient for adequate
sampling. Failure to follow these instructions will
prevent the smoke detector from performing its
design function.
Important: Airflow through the unit is affected by the
amount of dirt and debris accumulated on the indoor
coil and filters. To insure that the airflow through the
unit is adequate for proper sampling by the return air
smoke detector, more frequent replacing and/or
cleaning of these components is required.
Important: Periodic checks and maintenance
procedures must be performed on the smoke
detector to insure that it will function properly. For
detailed instructions concerning these checks and
procedures, refer to the appropriate section(s) of the
smoke detector Installation and Maintenance
Instructions provided with the literature package for
this unit.
In order for the return air smoke detector to properly sense
smoke in the return air stream, the air velocity entering the unit
must be between 500 and 4000 feet per minute. Equipment
covered in this manual will develop an airflow velocity that falls
within these limits over the entire airflow range specified in the
evaporator fan performance tables.
There are certain models however, if operated at low airflow,
will not develop an airflow velocity that falls within the required
500 to 4000 feet per minute range. For these models, the de-
sign airflow shall be greater than or equal to the minimum
specified in the table provided below.
Unit Model Minimum Allowable Airflow
Number with
Return Air Smoke Detector
YCD103 3400 CFM
YCD121 4100 CFM
YCD181 5300 CFM
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)

5
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.
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 Off Off On Off Off Off Off
6* Heat 2 On Min Off Off On On Off Off Off
7* Heat 3 ( Not Applicable on Electric/Electric or Gas Units )
8** Defrost ( Not Applicable on Electric/Electric or Gas Units )
9** Em Heat ( Not Applicable on Electric/Electric or Gas Units )
* 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
3COOL1 4.7K
4COOL2 6.8K
5HEAT1 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

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Dimensional Data
Unit Dimensions
UNITS A B C D E F G H J K
YC*100B,103C 63 5/16 93 3/4 13/16 49 28 5/8 2 3/16 8 3/8 44 15/16 5 15/16 2
YC*120B,125C
YC*150C
YC*085C,100C 49 9/16 88 3/8 N/A 45 1/2 25 5/8 1 13/16 6 3/4 42 11/16 6 3/8 2
YC*102C,120C
YC*121C -151C 70 13/16 106 3/4 13/16 5 0 1/8 29 5/16 2 11/16 8 3/8 57 5 15/16 2
YC*155B,175C
YC*180B,210C
YC*181C,200B 84 13/16 121 3/4 13/16 54 33 3/16 2 11/16 8 15/16 64 1/2 5 15/16 3
YC*211C,240B
YC*241C,250B
YC*300B,301C
* Downflow or Horizontal
HORIZONTAL UNIT
REAR VIEW SHOWING DUCT OPENINGS FOR HORIZONTAL AIR FLOW
UNITS A B C D E F
YC*100B,103C 22 1/2 18 17 3/16 23 15/16 41 7/16
YC*120B,125C
YC*150C
YC*085C,100C, 16 16 1/4 20 1/16 3 6 3/8 36
YC*102C,120C
YC*121C,151C 26 1/2 19 9/16 24 9/16 23 15/16 42 1/2
YC*155B,180B
YC*175C,210C
YC*181C,200B 26 1/2 24 1/16 27 9/16 23 15/16 46 7/16
YC*211C,240B
YC*241C,250B
YC*300B,301C
DOWNFLOW UNIT
TOP VIEW SHOWING DUCT OPENINGS IN THE BASE
UNITS A B C D E
YC*100B,103C 22 7/16 14 1/2 17 11/16 54 13/16 47 3/16
YC*120B,125C
YC*150C
YC*085C,100C 15 3/16 22 1/2 12 15/16 42 7/8 35 1/4
YC*102C,120C
YC*121C -151C 26 7/16 22 1/2 18 11/16 62 7/16 54 11/16
YC*155B,175C
YC*180B,210C
YC*181C,200B 26 7/16 28 3/4 19 15/16 76 5/16 68 11/16
YC*211C,240B
YC*241C,250B
YC*300B,301C
(YCD180 Illustrated)

7
Curb Dimensions
Figure UNITS A B C D E F G H J K LMNP
1A YC*100B,103C 59 1/8 55 7/16 1 13/16 19 1/8 9 7/8 24 1/2 88 15/16 59 7/16 89 1/4 2 14 1/16 1 6 1/2 4 7 7/16
1A YC*120B,125C
1A YC*150C
1B YC*085C,100C 81 1/4 46 1/16 14 14 3/8 17 1/4 18 1/4 42 3/8 2 1 13/16 36 3/16 81 5/8 46 3/8 N/A N/A
1B YC*102C,120C
1A YC*121C -151C 66 5/8 63 1 13/16 20 7/8 17 1/8 28 1/2 101 7/8 67 102 1/4 2 14 1/16 1 6 1/2 55 1/2
1A YC*155B,175C
1A YC*180B,210C
1A YC*181C,200B 80 5/8 77 1 13/16 22 1/4 23 1/4 28 9/16 116 13/16 81 117 3/16 2 14 1/16 1 6 1/2 69 1/2
1A YC*211C,240B
1A YC*241C,250B
1A YC*300B,301C
* G Dimension represents the distance from the top of the curb to the duct flange.
Figure 1A
Figure 1B

8
INSTALLATION
Location and Recommendations
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 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
Corner Weights (lbs.) Center of
Unit Net (See Note 1) Gravity (in.)
Description Weight ABCDLengthWidth
YC*085C 962 329 244 165 223 38 20
YC*102C 962 329 244 165 223 38 20
YC*103C 1233 395 326 231 280 43 26
YC*100B 1247 425 331 215 276 41 25
YC*120B 1247 425 331 215 276 41 25
YC*100C 984 334 252 171 227 38 20
YC*120C 984 334 252 171 227 38 20
YC*121C 1523 516 391 266 351 46 29
YC*125C 1300 430 342 234 294 42 26
YC*150C 1300 430 342 234 294 42 26
YC*151C 1547 523 383 271 370 45 30
YC*155B 1538 535 387 259 357 45 29
YC*180B 1538 535 387 259 357 45 29
YC*181C 2017 693 507 345 472 52 35
YC*175C 1619 553 415 279 372 46 29
YC*210C 1619 553 415 279 372 46 29
YC*211C 2088 701 538 369 480 53 35
YC*200B 2025 714 532 333 447 52 33
YC*240B 2025 714 532 333 447 52 33
YC*241C 2186 751 568 373 494 53 34
YC*250B 2082 721 552 351 458 53 33
YC*300B 2082 721 552 351 458 53 33
YC*301C 2191 755 569 373 495 53 34
*Downflow or Horizontal
Note: Corner weights are given for information only.
Unit is to be supported continuously by curb or
equivalent frame support.
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. Furnace may be installed on
Class A, B or C roofing material.
Location and Clearances
Installation of unit should conform to local building codes, the
National Fuel Gas Code, ANSI-Z223.1a Latest Revision, and
the National Electrical Code. Canadian installations must con-
form to CSA and local codes.
Model YC heating/cooling units are designed for outdoor
mounting with a vertical condenser discharge. They can be lo-
cated either at ground level or on a roof, in accordance with lo-
cal codes or the National Fuel Gas Code (ANSI-Z223.1a Lat-
est Revision). Since these units are designed exclusively for
outdoor operation, additional flue venting systems are not re-
quired. Each unit contains an operating charge of Refrigerant
22 as shipped.
Select a location that will permit unobstructed airflow into the
condenser coil and away from the fan discharge and permit
unobstructed combustion airflow into the burner compartment.
Suggested airflow clearances and service clearances are
given in Figure 1A and 1B .
.
Placing and Rigging
NOTE : Before attempting to rig the unit, remove the
fork lift pockets located on the condenser end of the
unit.
Figure 2
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.

9
Duct Dimensions
Figure UNITS ABCDE F G
3A YC*100B,103C 51 7/8 16 3/16 44 1/2 22 5/16 1 14 1/16 7 7/16
3A YC*120B,125C
3A YC*150C
3B YC*085C,100C 41 1/4 13 3/4 35 5/8 16 7/8 1 1/2 16 7/8 N/A
3B YC*102C,120C
3A YC*121C -151C 59 7/16 17 7/8 52 1/2 26 5/16 1 14 1/16 7 7/16
3A YC*155B,175C
3A YC*180B,210C
3A YC*181C,200B 73 7/16 19 5/16 66 1/2 26 5/16 1 14 1/16 7 7/16
3A YC*240C,250B
3A YC*300B,301C
* G Dimension represents the distance from the top of the curb to the duct flange.
Figure 3A Figure 3B
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.
The following warning complies with State of
California law, Proposition 65.
This product contains
fiberglass wool insulation! Fiberglass dust and
ceramic fibers are believed by the state of California
to cause cancer through inhalation. Glasswool
fibers may also cause respiratory, skin, or eye
irritation. See page 16 for precautionary and first aid
measures.
Guidelines for ductwork construction:
—Connections to the unit should be made with three-inch can-
vas connectors to minimize noise and vibration transmission.
—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 resis-
tance.
Attaching Horizontal Ductwork to Unit
— All conditioned air ductwork should be insulated to minimize
heating and cooling duct losses. Use minimum of 2" of insula-
tion 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 flex-
ible water tight connection to prevent noise transmission 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.

10
Condensate Drain Piping
A 3/4 inch PVC condensate drain connection is provided on
the YC,TC*085 - 120C units only. A 1 inch NPT female
condensate drain connection is provided on all other units.
Follow local codes and standard piping practices when run-
ning the drain line. Install a trap and be sure to fill with wa-
ter before starting the unit. Pitch the line downward, away
from the unit; avoid long, level, horizontal runs. Refer to
Figure 4.
Figure 4
Gas Piping Installation
Note: In the absence of local codes, the
installation must conform with American National
Standard-Z223.1a-National Fuel Gas Code Latest
Revision.
The following warning complies with State of
California law, Proposition 65
.Hazardous Gases!
Exposure to fuel substances or by-products of
incomplete fuel combustion is believed by the
state of California to cause cancer, birth defects, or
other product reproductive harm.
The available gas supply must agree with the required sup-
ply marked on the unit nameplate. Minimum permissible
gas supply pressure for purpose of input adjustment must
be at least 3.5 in. W.C. (inches water column) for natural
gas and 8 in. W.C. for LP gas. Manifold pressure is set at
(negative) -.2 in. W.C. at the factory for both Natural and LP
Gas.
Pipe Delivery Schedule
Note: The following procedure and tables apply to
Natural Gas only.
1. Obtain from gas company the heating value and specific
gravity of gas delivered.
2. Determine exact length of pipe needed.
3. Read BTUH input nameplate on furnace.
4. Use the multiplier opposite specific gravity of gas (Table
2) and insert in the following formula :
Furance input in BTUH
CFH
= Gas Heat Content in BTU/Cu. Ft. * Multi
p
ler
Table 2 Specific
Gravity Multiplier
Multipliers to be used when 0.50 1.10
the Specific Gravity of the 0.55 1.04
Gas is other than 0.60 0.60 1.00
0.65 0.962
This will give your factor for columns 2 through 6 in Table 3.
5 . Using Table 3, select nearest pipe length to yours.
6 . Follow this line horizontally across to the exact CFH found in
step 4 or the next highest figure.
7. Read vertically to top of this column for required pipe diameter.
Note: If this is a LPG (Liquid Propane Gas) application,
consult your LPG supplier for pipe sizes and deliveries.
Never use an open flame to
test for gas leaks. An explosion could occur, resulting in
severe personal injury or death.
Table 3 Iron Pipe Size
(IPS) Inches
Length of
Pipe (Ft.) 1/2" 3/4" 1" 1 1/4" 1 1/2"
15 76 176 345 750 1220
30 52 120 241 535 850
45 43 99 199 435 700
60 38 86 173 380 610
75 -- 77 155 345 545
Capacity of Pipe of Different Diameters and Lengths in Cu. Ft. Per
Hr. with Pressure Drop of 0.3" and Specific Gravity of 0.60
Gas Pressure Set-Up Precautions
Never use an open flame to
test for gas leaks. An explosion could occur, resulting in
severe personal injury or death.
IMPORTANT: The furnace and its individual shut-off valve
must be disconnected from the gas supply piping system
during any pressure testing of that system at test
pressures exceeding 1/2 psig (3.48 kpa).
Caution: This unit should never be exposed to gas line
pressures in excess of 14 inches water column (1/2 psig).
Pressures greater than this could damage the unit.

11
Gas Supply Line Pressures
Before connecting the unit to the gas supply line, be sure to
determine both gas pressure and gas BTU rating. In addition,
check all unit connections and supply piping for leaks. If the
gas supply pressure is excessive (above 14 inches water col-
umn, or 1/2 psig), install a pressure regulator either at the sup-
ply source, or in the branch circuit serving the unit. Once the
regulator is installed, set it to provide a pressure of 7 inches
water column with the unit operating and no greater than 14
inches water column with the unit not firing.
Caution: Gas pressure in excess of 14 inches water
column (1/2 psig) will damage the regulator, while
improper regulation may result at pressures lower
than 2.5 inches water column at the unit inlet. If the
supply line pressure is below the minimum supply
pressure indicated on the unit nameplate, contact the
gas supply company .
Use the following steps to complete the installation of the unit
gas piping. (see Figure 5)
1. Install a tapped, style A (1/8 inch NPT tap) shut-off gas cock
at the end of the gas supply line near the unit. Be sure the
tapped gas cock is downstream of the pressure regulator, if
used.
Note: The shut-off gas cock must be installed
outside the unit, and should meet the specifications
of all applicable National and Local Codes.
2 . Install a ground union joint downstream of the shut-off
cock. This joint must be installed outside of the unit.
3 . Install a drip leg (at least six inches in depth) next to the
union as shown in Figure 5. This drip leg is required to col-
lect any sediment that may be deposited in the line.
4 . Before connecting the piping circuit to the unit, bleed the air
from the supply line. Then cap or plug the line and test the
pressure at the tapped shut-off cock. The pressure reading
should not exceed 14 inches water column.
5 . Connect the gas piping to the unit. Check the completed
piping for leaks using a soap and water solution, or equiva-
lent.
Figure 5
Gas Piping Schematic
IMPORTANT NOTE: THIS UNIT USES A NEGATIVE
REGULATION GAS VALVE. AT START-UP, THE
OUTLET PRESSURE SHOULD BE CHECKED AND
ADJUSTED IF REQUIRED TO A (NEGATIVE) -0.2
INCHES OF WATER COLUMN. NEVER ADJUST THE
REGULATOR TO A POSITIVE PRESSURE.
Manifold Pressure
The unit manifold pressure regulator (located on the gas
valve) is factory installed and adjusted to provide the rated unit
heating capacity. The required manifold pressure is factory set
at (negative) - 0.2 inches of water column for natural and LP
gas.
Check the manifold pressure at the unit gas valve. Do not ex-
ceed the recommended pressure shown on the unit name-
plate.
Filter Installation
To gain access to filters, remove the evaporator fan access
panel. Each unit ships with 2 inch filters. Number and size of
filters is determined by size and configuration of the unit. Refer
to the unit “Service Facts” for filter requirements.
Evaporator Fan Adjustment
Use the following procedure to determine the proper adjust-
ment of the evaporator fan sheaves for a specific application.
1. Determine total system external static pressure (in inches
water 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 the Service Facts, add the 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
approximates total system external static pressure. Then
locate the appropriate airflow rate (in cfm) for your unit. The
value obtained represents the brake horsepower for the
evaporator fan motor and the fan RPM.
Important: Fan Break Horsepower (BHP) listed in the
Table is the percentage range of nameplate amperage
the motors will safely work within before an oversized
motor is required.
3. Adjust the variable pitch pulley to increase or decrease the
fan RPM as req uired. See Figure 6.

12
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.
IMPORTANT NOTE: Units with Scroll Compressors
only. Proper scroll compressor rotation is determined
by main power electrical connections.(See
Compressor Electrical Phasing section.)
Provide flexible conduit supports whenever vibration transmis-
sion may cause a noise problem within the building structure.
Insure all connections are made tight. (See Figure 7)
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, see the N.E.C. for de-rating the ampacity of each con-
ductor.
GROUNDING: THE UNIT MUST BE ELECTRICALLY
GROUNDED IN ACCORDANCE WITH LOCAL CODES AND
THE NATIONAL ELECTRICAL CODE.
Note: Unit must be grounded for igniter to operate
properly. Gas pipe to unit is not an adequate ground.
Ground the unit internally as provided. See unit
wiring diagram for location of grounding lug.
Control Wiring (Class II)
Note about Low Voltage Transformers:
Units have intergal circuit breakers in their low voltage trans-
formers. If the breaker trips, be sure to open the unit discon-
nect before attempting to reset the breaker.
Some earlier models 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 counterclockwise 1/4 turn, then
pull it out. To insert the new fuse, push in and turn clockwise
until it stop.
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
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.
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 6
Typical fan, motor, and sheave assembly
TO INCREASE CFM
Loosen the pulley adjustment set screw and turn sheave
clockwise
TO DECREASE CFM
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 desired 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 codes and with The National Electric Code
ANSI/NFPA70 Latest Revision.
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.
Important: All 208-230 volt units are factory wired for
230 volt applications. If the power supply voltage is
less than 215 VAC, refer to the unit wiring diagram
pasted to the inside of the control box cover or the
unit Service Facts, to convert the transformers to 208
volts.
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.

13
Figure 7
Typical Field Wiring Diagram
Low voltage control wiring must not be run in conduit with
power wiring. Route low voltage (class II) colored wire from
zone sensor terminals through 7/8 inch bushing in the unit.
See dimensional data for control wire entry location. Make
connections as shown by the appropriate low voltage wiring
diagrams in Figure 8.
Zone Temperature Sensor conductors are standard thermostat
wire 22 to 14 ga. The only exceptions are Tracer/Tracker in-
stallations which utilize a serial communications link and re-
quire a shielded twisted pair of conductors between the
Tracer/Tracker and the (TCI) Communications Interface.
Recommended wire sizes and lengths for installing the Zone
Temperature Sensor are provided in Table 4. Ensure that the
wiring between the controls and the unit's termination point
does not exceed two and a half (2.5) ohms/conductor for the
length of the run. Resistance in excess of 2.5 ohms per con-
ductor can cause deviation in the accuracy of the control.
Table 4.
DC Conductors
Distance from Unit Recommended
to Control Wire Size
000 - 150 feet 22 gauge
151 - 250 feet 20 gauge
241 - 375 feet 18 gauge
386 - 600 feet 16 gauge
611 - 975 feet 14 gauge
NOTE: Do not run the electrical wires transporting DC
signals in or around conduit housing high voltage
wires.
Zone Temperature Sensor and low voltage terminal
designations are no longer R-W-Y-G-B etc, they are now 1-2-3
etc. Connections should be made using 1 to 1, 2 to 2, 3 to 3,
and so on. See example below.
Zone Temperature Sensor Terminal Strip
Terminal # Terminal I.D.
1ZTEMP
2 SIGNAL COMMON
3CSP
4MODE
5HSP
6 LED COMMON
7 HEAT LED
8 COOL LED
9SYSONLED
10 SERVICE LED
Zone Low
Sensor Voltage
Module Terminal Board
(ZSM) (LTB)
1 [ ] [ ] 1
2 [ ] [ ] 2
3 [ ] [ ] 3
4 [ ] [ ] 4
5 [ ] [ ] 5
Emergency Shut Down
For Energency Shut Down, remove the jumper between LTB-
16 and LTB-17 and install normally closed contacts(Open at
Fault Condition). Immediate shut down will occur and the UCP
will be disabled.
Compressor Disable
To disable Compressor #1, remove the jumper between LTB-
13 and LTB-14 and install normally closed contacts (open to
disable).
To disable Compressor #2, (if applicable), remove the jumper
between LTB-14 and LTB-15 and install normally closed con-
tacts (open to disable).
Scroll Compressors
(103,151,181,200,211,240,241,300,301 Units only)
Because scroll compressors are uniquely different from tradi-
tional reciprocating compressors, their operating characteris-
tics and requirements represents a departure from reciprocat-
ing compressor technology.
Proper phasing of the electrical power wiring is critical for
proper operation and reliability of the scroll compressor.
Proper rotation of the scroll compressor must be established
before the unit is started. This is accomplished by confirming
that the electrical phase sequence of the power supply is cor-
rect. The motor is internally connected for clockwise rotation
with the inlet power supply phasedA, B, C.

14
Figure 8
Zone Sensor Interconnecting Correcting Diagram

15
Improper Electrical
Phase Sequence
Proper compressor motor electrical phasing can be quickly de-
termined and corrected before starting the unit. Use a quality
instrument such as an Associated Research Model 45 Phase
Sequence Indicator and follow this procedure.
1. Open the electrical disconnect or circuit protection switch
that provides line power to the High Voltage Terminal Block
(HTB1) in the control panel.
2. Connect the phase sequence indicator leads to the HTB1
as follows:
Phase Seq. Lead HTB1 Terminal
Black (Phase A) L1
Red (Phase B) L2
Yellow (Phase C) L3
Bodily injury can result
from high voltage electrical components. If operating
checks must be performed with the unit operating, it
is the technician’s responsibility to recognize these
hazards and proceed safely. Failure to do so could
result in severe personal injury or death due to
electrical shock or contact with moving parts.
3 . Read the phase sequence on the indicator after turning
power on by closing the unit disconnect switch. The “ABC” in-
dicator on the face of the phase indicator will glow if phase is
ABC.
4. If the “CBA” indicator glows instead, open the unit main dis-
connect and interchange any two main line leads on HTB1. re-
close the unit main disconnect and recheck phasing.
5. Open units main disconnect before continuing with installa-
tion.
6. Disconnect the phase indicator.
Open and lock unit
disconnect switch before continuing installation.
Failure to do so could result in severe personal injury
or death due to electrical shock or contact with
moving parts.
Note: If a phase indicator is not available, follow the
electrical phasing sequence in the cooling start-up
section to insure proper compressor rotation.
IMPORTANT: After completion of wiring, check all
electrical connections, including factory wiring within
the unit, and ensure all connections are tight. Replace
and secure all electrical box covers and access doors
before leaving unit or connecting power to circuit
supplying unit.
After all electrical wiring is complete, SET THE ZONE SEN-
SOR SWITCH TO THE OFF POSITION AND THE FAN
SWITCH TO AUTO SO COMPRESSORAND FAN WILL NOT
RUN, and apply power by closing the system main disconnect
switch. This will activate the compressor crankcase heaters.
Do not change the zone sensor setting until power has been
applied long enough to evaporate any liquid R-22 in the com-
pressor. It is recommended the crankcase heaters be ener-
gized for 8 hours prior to starting.
Exception - Circuit #1 on 181 and 211 units and both circuits
on the 200, 240 thru 301 units are not equipped with crank-
case heaters.
Start-Up
Pre-Start Quick Check List
[ ] Is unit properly located and level with proper clearances?
See Figure 1A and 1B.
[ ] Is the duct work correctly sized, run, taped, insulated and
weather proofed with proper unit arrangement? (see duct
work installation)
[ ] Is the gas piping correctly sized, run, and purged of air?
(See gas piping)
[ ] Is condensate line properly sized, run, trapped and
pitched?
[ ] Is the filter of the correct size and number, clean and in
place?
[ ] Is the wiring properly sized and run in according to the unit
wiring diagram?
[ ] Are all wiring connections tight including those in unit and
compressor electrical boxes?
[ ] Has the unit been properly grounded and fused with the
recommended fuse size? (see wiring data)
[ ] Is the zone temperature sensor correctly wired and in a
good location?
[ ] Have the air conditioning systems been checked at the
service ports for charge and leak tested if necessary?
[ ] Does the condenser fan and indoor blower turn freely
without rubbing and are they tight on the shafts?
[ ] Has the indoor blower speed been determined and the
proper speed been set? (see air flow performance data)
[ ] Has all work been done in accordance with applicable local
and national codes?
[ ] Are all covers and access panels in place to prevent air
loss and safety hazards?

16
Bodily injury can result
from high voltage electrical components. If operating
checks must be performed with the unit operating, it
is the technician’s responsibility to recognize these
hazards and proceed safely. Failure to do so could
result in severe personal injury or death due to
electrical shock or contact with moving parts.
Power-up Initialization
The “initialization” by the Unitary Control Processor (UCP) oc-
curs each time the system is powered-up. The UCP performs
internal self- diagnostics checks, which include identifying the
equipment components of its system, and the configuring of it-
self to that system. It also checks itself to be sure it is function-
ing correctly. On units with the optional economizer, the
damper is driven open for 15-20 seconds and then fully closed
for 90 seconds. The UCP system indicator LED is turned to
“ON” within one second of start-up if operation is correct.
The Unitary Control Processor (UCP) switches are factory set
to provide comfort for most applications. Control cycles may
be adjusted as indicated in the table below. These switches
function similar to the heat anticipator adjustment in conven-
tional thermostats.
Unitary Control Processor (UCP)
Switch Settings for Cycle Timing
Switch 1 Switch 2 Cycle Time
OFF OFF NORMAL (Factory Setting)
OFF ON LONGER
ON OFF SHORTER
ON ON *SPECIAL
* Special applications, where very short cycles are
necessary to prevent excessive temperature swings.
Starting the Unit in the Heating Mode
Note: See “Sequence of operation” in the unit Service
Facts for a complete description of heating operating
sequence.
Check to ensure all grilles and registers are open and all unit
access doors are closed before start-up.
Purge the gas supply line of air by opening the union ahead of
the unit. When the odor of gas is detected, re-tighten union
and wait 5 minutes before proceeding.
Place the zone system switch in the heat position.
Postition the heating setpoint approximately 10 degrees above
room temperature and place the fan switch in "Auto" or "On"
position.
Open the main gas valve and turn on unit main power
supply.
Note: To bypass time delays, and verify the operation
of this unit from the roof, use the “Test mode
procedure” on page 3 and 4 of this manual.
The combustion blower motor and ignitor should energize.
The main burners should light within one minute from the time
the combustion blower starts. Initial start may be delayed
somewhat if unit is not purged and air is trapped in gas line.
If burners fail to ignite after 3 tries the ignition system will lock-
out. Reset by disconnecting and re-applying unit power.
Unit will start in the high fire mode. After a short run cycle it will
switch to low fire.
Note: Blue smoke produced by the heat exchanger
during the initial burner firing is caused by a thin film
of oil on the surface of the heat exchanger. This oil
will burn off quickly.
Check control operation and burner operating conditions
through the sight glass in burner assembly cover.
Manifold Pressure
Connect a manometer to the pressure tap at the outlet side of
the unit gas valve. Read the manifold pressure with the main
burners firing. The manifold pressure reading indicated should
be a (negative) -0.2 inch water column for natural and L.P.
gas.
If the manifold pressure reading does not match the value indi-
cated on the unit nameplate, the unit pressure regulator must
be adjusted as follows:
Remove the cover screw on the gas regulator (located on the
top side of the unit gas valve).
Turn the adjusting screw clockwise to increase manifold pres-
sure, or counterclockwise to decrease manifold pressure.
Open and lock unit
disconnect switch before continuing installation.
Failure to do so could result in severe personal injury
or death due to electrical shock or contact with
moving parts.
Adjust the evaporator fan motor rpm (at the motor sheave) to
a speed which most closely approximates the rpm value found
in the motor sheave/fan speed (rpm) table in the Service
Facts. To insure proper unit operation, the resulting airflow
must be within + or - 20 percent of the nominal airflow rate.
After adjusting the evaporator fan, check heat exchanger tem-
perature rise during furnace operation to insure that it falls
within the range specified on the unit nameplate.
If the temperature rise noted is outside of the specified limits,
adjust the fan motor sheave to cause the temperature rise of
the heat exchanger to fall within the required range.
Heating Shut-down
To exit the test mode, disconnect unit power for 3-5 seconds
and reapply. When running the unit using the zone sensor as
the control, position the selector switch at "Off". There will be a
delay of 0 - 90 seconds before the unit shuts down in this set-
ting.
Do not operate the unit
without the evaporator fan access panel in place.
Reinstall the access panel after performing any
maintenance procedures on the fan. Operating the
unit without the access panel properly installed may
result in severe personal injury or death.

17
Note: Always route refrigerant hoses through the port
hole provided and have compressor access panel in
place.
Check the suction and discharge pressures and compare
them to the normal operating pressures provided in the unit’s
Service Facts.
Note: Do not use pressures from Service Facts to
determine the unit refrigerant charge. The correct
charge is shown on the unit nameplate. To charge the
system accurately, weigh the cha rge.
Voltage
With the compressor operating, check the line voltage at the
unit. The voltage should be within the range shown on the unit
nameplate. If low voltage is encountered, check the size and
length of the supply line from the main disconnect to the unit.
The line may be undersized for the length of the run.
Cooling Shut Down
To exit the test mode, disconnect unit power for 3-5 seconds
and reapply. When running the unit using the zone sensor as
the control, position the selector switch at “Off”. There may
be a delay of up to 3 minutes before compressors shut down
and an additional 1 minute before the fan shuts down in this
setting.
Do not de-energize main power disconnect except when unit
is to be serviced. Power is required to keep air conditioning
compressor crankcase warm and boil off refrigerant in the oil.
Exception - Circuit #1 on 181 and 211 units and both circuits
on the 200, 240 thru 301 units are not equipped with crank-
case heaters.
Compressor Overload Protection
Important: Circuit #1 on the 181 and 211 units and
both circuits of the 200,240,241,300 and 301 are
equipped with external compressor overload
protection. When an overload is detected the
breaker(s) will trip and the UCP will lock out the
compressor(s). When this happens, the breaker(s)
and the UCP must be reset.
To reset the breaker(s), open and lock unit disconnect.
Remove the compressor access panel. It is not necessary to
remove the control box cover. To reset the breaker, move the
toggle handle up. Replace the compressor access panel.
Close unit disconnect switch to resume normal operations, do-
ing this will reset the UCP.
(EDC) Evaporator Defrost Control
During low ambient operation (below 55 degree F for single
condenser fan units, and below 40 degree F for dual con-
denser fan units) compressor run time is accumulated by the
UCP. When compressor run time reaches approximately 10
minutes, an evaporator defrost cycle is initiated. The defrost
cycle lasts approximately 3 minutes.
During a defrost cycle, The compressor(s) are turned off and
the indoor motor continues to run.After completing the defrost
cycle the unit returns to normal operation, and the compressor
Starting The Unit In The Cooling Mode
IIMPORTANT NOTE: Before starting the system in the
cooling cycle, turn the zone sensor switch to “off”
and close the unit disconnect switch. This procedure
energizes the compressor crankcase heaters,
vaporizing any liquid refrigerant in the crankcase.
This is a precaution against foaming at start-up,
which could damage the compressor bearings. Allow
the heater to operate for a minimum of eight hours.
Exception - Circuit #1 on 181 and 211 units and both circuits
on the 200, 240 thru 301 units are not equipped with crank-
case heaters.
Electrical Phasing (Scroll Compressors) If compressor
electrical phasing is incorrect , compressor and indoor fan
will operate in reverse, several symptoms will be apparent.
Compressors will draw low current.
Suction and discharge pressure will change very little.
A slight rattling or rumbling sound may be apparent.
Unit will not cool
Indoor fan (evaporator) will run backwards
If allowed to run backward for an extended period (5 minutes),
the motor windings will overheat and cause the compressor to
cycle on its thermal protector and the oil will be pumped out of
the compressor.
To correct the rotation, open unit disconnect and interchange
any two of the line wires at the high voltage terminal block, in
the control box.
Open and lock unit
disconnect switch before continuing installation.
Failure to do so could result in severe personal injury
or death due to electrical shock or contact with
moving parts.
Verify that the unit airflow rate is adjusted according to infor-
mation provided in “Determining Evaporator Fan Adjustment”
section of this manual.
Note: See “Sequence of operation” in the unit
Service Facts for a complete description of cooling
operating sequence.
To start the unit in the cooling mode, Close unit disconnect
switch and set the zone sensor system switch to COOL and
move the cooling setpoint approximately 10 degrees below
room temperature. There will be a delay of up to 5 minutes be-
fore the unit will start automatically.
To bypass time delays, and verify the operation of this unit
from the roof, use the “Test mode procedure” on page 3 and 4
of this manual.
Operating Pressures
After the unit has operated in the cooling mode for a short pe-
riod of time, install pressure gauges on the gauge ports of the
discharge and suction line valves.

18
run time counter is reset to zero.
Economizer operation is not affected by a defrost cycle.
Final Installation Checklist
[ ] Does unit run and operate as described in the “Sequence of
Operation” in the unit Service Facts?
[ ] Is the condenser fan and indoor blower operating correctly,
with proper rotation and without undue noise?
[ ] Is the compressor operating correctly and has the system
been checked with a charging chart?
[ ] Have voltage and running currents been checked to deter-
mine if it is with limits?
[ ] Have the air discharge grilles been adjusted to balance the
system?
[ ] Has the ductwork been checked for air leaks and condensa-
tion?
[ ] Has the furnace manifold pressure been checked and ad-
justed if necessary?
[ ] Has the heating air temperature rise been checked?
[ ] Has the indoor airflow been checked and adjusted if neces-
sary?
[ ] Has the unit been checked for tubing and sheet metal
rattles and are there unusual noises to be checked?
[ ] Are all covers and panels in place and properly fastened?
[ ] Has the owner or maintenance personnel been given this
manual, warranty, and been instructed on proper operation
and maintenance?
Routine Maintenance by Owner
You can do some of the periodic maintenance functions for
your unit yourself; this includes replacing (disposable) or clean-
ing (permanent) air filters, cleaning unit cabinet, clearing the
condenser coil, and conducting a general unit inspection on a
regular basis.
Season Maintenance - Cooling
To keep the unit operating safely and efficiently, the manufac-
turer recommends that a qualified serviceman check the entire
system at least once each year, or more frequently if conditions
warrant.
Examine these areas of unit:
1. Filters (for cleaning or replacement)
2. Motors and drive system components
3. Economizer gaskets (for possible replacement)
4. Condenser coils (for cleaning)
5. Safety Controls (for mechanical cleaning)
6. Electrical components and wiring (for possible replacement
or connection tightness)
7.Condensate drain (for cleaning)
8.Inspect the unit duct connections to ensure they are physi-
cally sound and sealed to the unit casing.
9. Inspect the unit mounting support to see that it is sound.
10.Inspect the unit to ensure there is no obvious deterioration.
Season Maintenance - Heating
Complete the unit inspections and service routines described
below at the beginning of each heating season.
To prevent injury or death
due to electrical shock of contact with moving parts,
lock unit disconnect switch in open position before
servicing unit.
To prevent an explosion
and possible injury, death and equipment damage, do
not store combustible materials, gasoline or other
flammable vapors and liquids near the unit.
[ ] Visually inspect the unit to ensure that the airflow required
for combustion is not obstructed from the unit.
[ ] Visually inspect the flue stack to ensure the exhaust path is
clear and free of obstructions.
[ ] Inspect the control panel wiring to verify that all electrical
connections are tight, and that wire insulation intact.
[ ] Check the operation of the gas ignition system: To do this,
turn off the gas supply with the unit operating to verify that
the gas valve closes, and that a re-ignition cycle is initiated
by the unit.
[ ] Visually inspect all of the unit’s flue product passageways
for excessive deposit buildup and corrosion. If buildup or
corrosion is apparent, perform the necessary repairs.
The following warning complies with State of
California law, Proposition 65.
This product contains
fiberglass wool insulation! Fiberglass dust and ceramic
fibers are believed by the state of California to cause
cancer through inhalation. Glasswool fibers may also
cause respiratory, skin, or eye irritation.
PRECAUTIONARY MEASURES
* Avoid breathing fiberglass dust.
* Use a NIOSH approved dust/mist respirator.
* Avoid contact with the skin or eyes. Wear long-
sleeved, loose-fitting clothing, gloves, and eye
protection.
* Wash clothes separately from other clothing: rinse
washer thoroughly.
* Operations such as sawing, blowing, tear-out, and
spraying may generate fiber concentrations requiring
additional respiratory protection. Use the appropriate
NIOSH approved respirator in these situations.
First Aid Measures
Eye Contact Flush eyes with water to remove dust.
If symptoms persist, seek medical
attention.
Skin Contact Wash affected areas gently with soap
and warm water after handling.

19
This warranty is extended by American Standard Inc., to the original purchaser and to any succeeding owner of the
real property of which the Combination Gas-Electric Air Conditioner is an original fixture, and applies to products
purchased and retained for use within the U.S.A.. There is no warranty against corrosion, erosion, or de-
terioration.
If any part of your Combination Gas-Electric Air Conditioner fails because of a manufacturing defect within one
year from date of original purchase, Warrantor will furnish without charge the required replacement part.
In addition, if the sealed motor-compressor fails because of a manufacturing defect within the second through the
fifth year from the date of original purchase, Warrantor will furnish without charge a replacement compressor.
In addition, if the steel heat exchanger fails because of a manufacturing defect within the second through fifth** year
from date of original purchase, Warrantor will furnish without charge a replacement heat exchanger.
Warrantor’s obligations and liabilities under this warranty are limited to furnishing, F.O.B. factory or warehouse at
Warrantor designated shipping point, freight allowed to Buyer’s city, replacement parts (or equipment at the option of
Warrantor) for all Warrantor’s products not conforming to this warranty. Warrantor shall not be obligated to pay for
the cost of lost refrigerant. No liability whatever shall attach to Warrantor until said products have been paid for and
then said liability shall be limited to the purchase price of the equipment shown to be defective.
THE WARRANTY AND LIABILITY SET FORTH HEREIN ARE IN LIEU OF ALL OTHER WARRANTIES AND
LIABILITIES, WHETHER IN CONTRACT OR IN NEGLIGENCE, EXPRESS OR IMPLIED, IN LAW OR IN FACT,
INCLUDING IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR PARTICULAR USE, IN NO
EVENT SHALL WARRANTOR BE LIABLE FOR ANY INCIDENTAL OR CONSEQUENTIAL DAMAGES.
Manager — Product Service
American Standard Inc.
Clarksville, TN 37040-1008
American Standard Inc.,
The Trane Co.
Clarksville, TN 37040-1008
Warrantor
GW-501-3888
*Commercial Use is any application where the end purchaser uses the product for other than personal, family or
household purposes.
**Optional Extended sixth (6th) through tenth (10th) year limited warranty for heat exchanger is available.
LIMITED WARRANTY
COMBINATION GAS-ELECTRIC AIR CONDITIONER
BYC, YCC, YCD, YCG and YCH MODELS for Commercial Use*.
Models Less than 20 Tons
Single or Three-Phase electric power.
(Parts Only)

20
WARRANTY AND LIABILITY CLAUSE
COMMERCIAL EQUIPMENT
RATED 20 TONS AND LARGER AND RELATED ACCESSORIES
THE WARRANTY AND LIABILITY SET
FORTH HEREIN ARE IN LIEU OF ALL
OTHER WARRANTIES AND LIABILITIES,
WHETHER IN CONTRACT OR IN
NEGLIGENCE, EXPRESS OR IMPLIED, IN
LAW OR IN FACT, INCLUDING IMPLIED
WARRANTIES OF MERCHANTABILITY
AND FITNESS FOR PARTICULAR USE, IN
NO EVENT SHALL WARRANTOR BE
LIABLE FOR ANY INCIDENTAL OR
CONSEQUENTIAL DAMAGES.
Manager - Product Service
American Standard Inc.
Clarksville, Tn 37040-1008
PW-215-2688
*Optional Extended Warranties are available for
compressors and heat exchangers of Combination
Gas-Electric Air Conditioning Units.
PRODUCTS COVERED - This warranty* is extended
by American Standard Inc. and applies only to
commercial equipment rated 20 Tons and larger and
related accessories.
Warrantor warrants for a period of 12 months from
initial start-up or 18 months from date of shipment,
whichever is less, that the products covered by this
warranty (1) are free from defects in material and
manufacture and (2) have the capacities and ratings
set forth in catalog and bulletins; provided, that no
warranty is made against corrosion, erosion or
deterioration. Warrantor's obligation and liabilities
under this warranty are limited to furnishing
replacement parts. Warrantor shall not be obligated
to pay for the cost of lost refrigerant. No liability
whatever shall attach to warrantor until said products
have been paid for and then said liability shall be
limited to the purchase price of the equipment shown
to be defective.