Table of Contents
Advertisement
WARNING
!
ELECTRICAL SHOCK FIRE/EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury or death and property damage.
Before making any wiring changes, make sure the gas
supply is switched off first. Then switch off the power
supply to the unit and install lockout tag.
Control Voltage Connections
Do not use any type of power- -stealing thermostat. Unit control
problems may result.
Use no. 18 American Wire Gage (AWG) color- -coded, insulated
(35_C minimum) wires to make the control voltage connections
between the thermostat and the unit. If the thermostat is located
more than 100 ft (30.5 m) from the unit (as measured along the
control voltage wires), use no. 16 AWG color- -coded, insulated
(35_C minimum) wires.
Standard Connection
Run the low- -voltage leads from the thermostat, through the inlet
hole, and into unit low- -voltage splice box.
Locate six (seven for 3- -phase) 18- -gage wires leaving control box.
These low- -voltage connection leads can be identified by the colors
red, green, yellow, brown, blue, and white (See Fig. 10). A gray
wire is standard on 3- -phase units for connection to an economizer.
Ensure the leads are long enough to be routed into the low- -voltage
splice box (located below right side of control box). Route leads
through hole in bottom of control box and make low- -voltage
connections (See Fig. 10). Secure all cut wires, so that they do not
interfere with operation of unit.
HIGH VOLTAGE
POWER LEADS
(SEE UNIT WIRING
LABEL)
3-PHASE SHOWN
1-PHASE USES
TWO POWER
EQUIP GR
LEADS
CONTROL BOX
LOW-VOLTAGE
POWER LEADS
(SEE UNIT
WIRING LABEL)
SPLICE BOX
Fig. 10 - - High- - and Control- -Voltage Connections
Heat Anticipator Setting (Electro- - Mechanical
Thermostats only)
The room thermostat heat anticipator must be properly adjusted to
ensure proper heating performance. Set the heat anticipator, using
an ammeter between the W and R terminals to determine the exact
required setting.
NOTE: For thermostat selection purposes, use 0.18 amp for the
approximate required setting. Failure to make a proper heat
anticipator adjustment will result in improper operation, discomfort
POWER
SUPPLY
FIELD-SUPPLIED
FUSED DISCONNECT
WHT(W)
W
YEL(Y)
Y
GRN(G)
G
THERMOSTAT
RED(R)
(TYPICAL)
R
BRN(C)
C
BLU(DH)
DH
GRA(Y2)
3-Phase
Only
A09053
to the occupants of the conditioned space, and inefficient energy
utilization; however, the required setting may be changed slightly
to provide a greater degree of comfort for a particular installation.
Transformer Protection
The transformer is of the energy- -limiting type, however a direct
short will likely blow a secondary fuse. If an overload or short is
present, correct overload condition and check for blown fuse on
Indoor Fan board or Integrated Gas Controller. Replace fuse as
required with correct size and rating.
PRE- - START- - UP
WARNING
!
ENVIRONMENTAL,
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
1. Follow recognized safety practices and wear protective
goggles when checking or servicing refrigerant system.
2. Do not operate compressor or provide any electric power
to unit unless compressor plug is in place and secured.
3. Do not remove compressor plug until all electrical
sources are disconnected and tagged.
4. Relieve and recover all refrigerant from system before
touching or disturbing compressor plug if refrigerant
leak is suspected around compressor terminals.
5. Never attempt to repair soldered connection while
refrigerant system is under pressure.
6. Do not use torch to remove any component. System
contains oil and refrigerant under pressure.
To remove a component, wear protective goggles and
proceed as follows:
a. Shut off electrical power to unit and install
lockout tag.
b. Relieve and reclaim all refrigerant from system
using both high- - and low- -pressure ports.
c. Cut component connecting tubing with tubing
cutter and remove component from unit.
d. Carefully unsweat remaining tubing stubs when
necessary. Oil can ignite when exposed to torch
flame.
Use the Start- -Up Checklist supplied at the end of this book and
proceed as follows to inspect and prepare the unit for initial
start- -up:
1. Remove access panels (see Fig. 20).
2. Read and follow instructions on all DANGER, WARNING,
CAUTION, and INFORMATION labels attached to, or
shipped with unit.
3. Make the following inspections:
a. Inspect for shipping and handling damage, such as
broken lines, loose parts, disconnected wires, etc.
b. Inspect all field- - and factory- -wiring connections. Be
sure that connections are completed and tight.
c. Ensure wires do not touch refrigerant tubing or sharp
sheet metal edges.
d. Inspect coil fins. If damaged during shipping and
handling, carefully straighten fins with a fin comb.
12
FIRE,
EXPLOSION,
Advertisement
Table of Contents
