Fig. 10 — Make Electrical Connections
Step 6 — Make Electrical Connections
FIELD POWER SUPPLY — Unit is factory wired for volt- age shown on nameplate.
When installing units, provide a disconnect, per NEC (National Electrical Code) requirements, of adequate size (Table 2).
All field wiring must comply with NEC and local requirements.
Route power lines through control box access panel or unit basepan (Fig. 4 and 5) to connections as shown on unit wiring diagram and Fig. 11.
Operating voltage to compressor must be within voltage range indicated on unit nameplate. On
The correct power phasing is critical in the operation of the scroll compressors. An incorrect phasing will cause the compressor to rotate in the wrong direction. This may lead to premature compressor failure.
Use the following formula to determine the percentage of voltage imbalance.
Percentage of Voltage Imbalance
=100 x max voltage deviation from average voltage average voltage
EXAMPLE: Supply voltage is
AB = 452 v
BC = 464 v
AC = 455 v
455 + 464 + 455
Average Voltage =
3
1371
=
3
= 457
Determine maximum deviation from average voltage:
IMPORTANT: If the supply voltage phase imbalance is more than 2%, contact your local electric utility com- pany immediately.
Unit failure as a result of operation on improper line voltage or excessive phase imbalance constitutes abuse and may cause damage to electrical components.
FIELD CONTROL WIRING — Install a
Route thermostat cable or equivalent single leads of no. 18 AWG (American Wire Gage) colored wire from subbase termi- nals through conduit in unit to
NOTE: For wire runs up to 50 ft, use no. 18 AWG insulated wire (35 C minimum). For 50 to 75 ft, use no. 16 AWG insu- lated wire (35 C minimum). For over 75 ft, use no. 14 AWG insulated wire (35 C minimum). All wire larger than no. 18 AWG cannot be directly connected to the thermostat and will require a junction box and splice at the thermostat.
Set heat anticipator settings as indicated in Table 3. Settings may be changed slightly to provide a greater degree of comfort for a particular installation.
TB1 MAXIMUM WIRE SIZE
UNIT |
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| VOLTAGE |
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50TJ |
| 208/230,380 |
| 460 | 575 | |
| All | 350 kcmil |
| 2/0 | 2/0 | |
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| LEGEND |
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EQUIP — Equipment |
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GND | — Ground |
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kcmil | — Thousand Circular Mils |
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NEC | — National Electrical Code |
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TB | — Terminal Block |
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Fig. 11 — Field Power Wiring Connections
(AB) 457 – 452 = 5 v (BC) 464 – 457 = 7 v (AC) 457 – 455 = 2 v
Maximum deviation is 7 v. Determine percent voltage imbalance:
Percentage of Voltage Imbalance = 100 x
7
THERMOSTAT ASSEMBLY
REMOVABLE JUMPER |
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RH RC | Y1 | Y2 | W1 | W2 | G | C | L | X |
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R | Y1 | Y2 | W1 | W2 | G | C |
| X |
457
= 1.53%
This amount of phase imbalance is satisfactory as it is be- low the maximum allowable 2%.
RED | BLU | PNK | ORN | VIO | BLK | BRN | WHT |
UNIT
Fig. 12 — Field Control Thermostat Wiring
8