The electrical data lists fuse and wire sizes (75ºC 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 “HACR Type” 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.
WIRING — LOW VOLTAGE WIRING
230/208V, 1 phase and 3 phase equipment 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:
TABLE 4
OPERATING VOLTAGE RANGE
TAP | RANGE | ||
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|
|
|
240V | 253 | - | 216 |
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|
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208V | 220 | - | 187 |
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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.)
Five (5) wires should be run from thermostat subbase to the 24V terminal board in the unit. A five conductor, 18 gauge copper,
TABLE 5
THERMOSTAT WIRE SIZE
|
|
| Maximum |
Transformer |
| Wire | Distance |
VA | FLA | Gauge | In Feet |
|
| 20 gauge | 45 |
|
| 18 gauge | 60 |
55 | 2.3 | 16 gauge | 100 |
|
| 14 gauge | 160 |
|
| 12 gauge | 250 |
TABLE 6
WALL THERMOSTAT AND SUBBASE COMBINATIONS
Thermostat | Subbase | Predominate Features | ||
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| ||
1 stage heat, 1 stage cool | ||||
T87F3111 | Q539A1220 | System: | Fan: | |
1 stage heat, 1 stage cool | ||||
T8034C |
| System: | Fan: | |
1 stage cool, 2 stage heat | ||||
T874C1760 | Q674A1001 | System: | Fan: | |
|
|
| ||
2 stage cool, 2 stage heat | ||||
T874D1934 | Q674A1001 | System: | Fan: | |
|
|
| ||
2 stage cool, 2 stage heat | ||||
| Electronic 7 day programming | |||
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|
| ||
1 stage heat, 1 stage cool | ||||
System: | Fan: | |||
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Manual