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WIRING – MAIN POWER
Refer to the unit rating plate for wire sizing information
and maximum fuse or circuit breaker size. Each
outdoor unit is marked with a "Minimum Circuit
Ampacity". This means that the field wiring used must
be sized to carry that amount of current. Depending
on the installed KW of electric heat, there may be
two field power circuits required. If this is the case,
the unit serial plate will so indicate. All models are
suitable only for connection with copper wire. Each
unit and/or wiring diagram will be marked "Use Copper
Conductors Only". These instructions must be adhered
to. Refer to the National Electrical Code (NEC) for
complete current carrying capacity data on the various
insulation grades of wiring material. All wiring must
conform to NEC and all local codes.
The electrical data lists fuse and wire sizes (75° C
copper) for all models including the most commonly
used heater sizes. Also shown are the number of field
power circuits required for the various models with
heaters.
The unit rating plate lists a "Maximum Time Delay
Relay Fuse" or circuit breaker that is to be used with
the equipment. The correct size must be used for
proper circuit protection and also to assure that there
will be no nuisance tripping due to the momentary high
starting current of the compressor motor.
The disconnect access door on this unit may be locked
to prevent unauthorized access to the disconnect. To
convert for the locking capability, bend the tab located
in the bottom left-hand corner of the disconnect
opening under the disconnect access panel straight
out. This tab will now line up with the slot in the door.
When shut, a padlock may be placed through the hole
in the tab preventing entry.
See "Start Up" section for important information on
three phase scroll compressor start ups.
See Tables 7 and 8 on pages 26 and 27 for electrical
specifications.
WIRING – LOW VOLTAGE WIRING
All 230/208V 1 phase and 3 phase equipment have
dual primary voltage transformers. All equipment
leaves the factory wired on 240V tap. For 208V
operation, reconnect from 240V to 208V tap. The
acceptable operating voltage range for the 240 and
208V taps are:
TAP
240
208
NOTE: The voltage should be measured at the field
power connection point in the unit and while
the unit is operating at full load (maximum
amperage operating condition).
RANGE
253 – 216
220 – 187
For low voltage wiring, an 18 gauge copper, color-coded
cable is recommended. See Table 4 on page 16 for
more information.
Low Voltage Connections
These units use a 24-volt AC low voltage circuit.
The "RT" terminal is the 24V transformer output,
and the "R" terminal is the 24VAC hot terminal
for the operation of the equipment. "RT" and "R"
are connected with brass jumper bar which can be
removed and "RT" and "R" connected to external
NC (normally closed) contact such as a fire/smoke
detector that will cause immediate shutdown of the
equipment upon activation.
"C" terminal is grounded.
"G" terminal is the fan input.
"Y1" terminal is the 1st Stage input for cooling.
"Y2" terminal is the 2nd Stage compressor input for
cooling (if equipped with an economizer).
"B/W1" terminal is the 1st stage electric heat.
"W2" terminal is the 2nd stage heat (if equipped).
"A" terminal is the ventilation input. This terminal
energizes any factory-installed ventilation option and
indoor blower.
"D" terminal is the dehumidification input. If
installed, this terminal energizes any factory installed
dehumidification option.
For units equipped with an alarm relay:
"L/1" terminal is the normally closed contact on the
relay.
"2" terminal is the normally open contact on the relay.
"3" terminal is the common contact on the relay.
LOW VOLTAGE CONNECTIONS FOR DDC CONTROL
Standard Units
Fan Only
Energize G
1st Stage
Energize Y1, G
Cooling Mode
2nd Stage
Cooling Mode
1st Stage Heating
Energize B/W1
2nd Stage Heating
Energize B/W1, W2
(if employed)
Ventilation
Energize A
Dehumidification
Energize D
(if employed)
Units w/
Economizers
Energize G
Energize Y1, G
Energize Y1, Y2, G
Energize B/W1
Energize B/W1, W2
Energize A
Energize D
Manual 2100-640D
Page
15 of 32
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