64
Table 7E — Electrical Data High Ambient 125 F Data, Duplex Units (High-Static Condenser Fan) (cont)
LEGEND
*Amperages in ( ) are for units with cooler heaters installed.
†Wye-delta start is standard. Across-the-line start is not available.
**Circuit A/Circuit B.
NOTES:
1. Main power must be supplied from a field-supplied fused electrical service with a
(factory or field-installed) disconnect located in sight from the unit.
2. Cooler heater, oil heater, and control circuit power must be supplied from a separate
source through a field-supplied disconnect. The control circuit power transformer acces-
sory may be applied to power from the main unit power supply.
3. Maximum incoming wire size for each terminal block is 500 kcmil.
4. Maximum allowable supply voltage phase imbalance is voltage 2%.
5. Never operate a motor where a phase imbalance in supply voltage is greater than 2%.
Use the following formula to determine the percent voltage imbalance.
Percent Voltage Imbalance
Example: Supply voltage is 240-3-60.
AB = 243 v
BC = 236 v
AC = 238 v
Determine maximum deviation from average voltage:
(AB) 243 – 239 = 4 v
(BC) 239 – 236 = 3 v
(AC) 239 – 238 = 1 v
Maximum deviation is 4 v. Determine percent voltage imbalance:
This amount of phase imbalance is satisfactory as it is below the maximum allow-
able 2%.
UNIT
30GXN,R
UNIT VOLTAGE
POWER
SUPPLY
QTY. REQD
HIGH-STATIC CONDENSER FAN CONTROL CIRCUIT
V-Hz
(3 Ph)
Supplied
# Power Supply
Conductors
MCA MOCP
ICF Rec Fuse Size
V-Hz
(Single Ph)
MCA and
MOCP*
Min Max XL WD XL WD
418A,
528A,B
208/230-60 187 253 2 12 752/652** 1000/800** † 1077.4/976.6** † 800/700** 115-60 30 (50)
230-60 207 253 2 12 681/612** 800/800** † 1045.6/976.6** † 700 115-60 30 (50)
460-60 414 506 1 6 593 700 1578.4 774.4 700 700 115-60 30 (50)
575-60 518 633 1 6 477 500 1265.3 622.3 600 600 115-60 30 (50)
380-60 342 418 1 6 713 800 1783.5 894.5 800 800 230-60 15 (25)
453A/B,
478B
208/230-60 187 253 2 12 693/488** 1000/700** † 1017.9/722.4** † 800/600** 115-60 30 (50)
230-60 207 253 2 12 627/461** 800/600** † 991.8/722.4** † 800/600** 115-60 30 (50)
460-60 414 506 1 6 504 600 1490.2 686.2 600 600 115-60 30 (50)
575-60 518 633 1 3 406 500 1194.4 551.4 450 450 115-60 30 (50)
380-60 342 418 1 6 607 700 1677.3 788.3 700 700 230-60 15 (25)
475A,
500A/B
208/230-60 187 253 2 12 753/518** 1000/700** † 1077.7/756.2** † 1000/600** 115-60 30 (50)
230-60 207 253 2 12 681/486** 800/700** † 1045.6/756.2** † 800/600** 115-60 30 (50)
460-60 414 506 1 6 540 600 1526.3 722.3 600 600 115-60 30 (50)
575-60 518 633 1 6 433 500 1221.8 578.8 500 500 115-60 30 (50)
380-60 342 418 1 6 651 800 1721.2 832.2 700 700 230-60 15 (25)
ICF —
Maximum Instantaneous Current Flow
MCA —
Minimum Circuit Ampacity (for wire sizing)
MOCP —
Maximum Overcurrent Protection
Rec Fuse Size —
Recommended Dual-Element Fuse Amps (150% of largest
compressor rated load amps [RLA] plus 100% of remaining
compressor RLAs and sum of condenser fan full load amps
[FLAs]. Choose next largest standard fuse size.)
WD —
Wye-Delta Start
XL —
Across-the-Line Start
= 100 x
max voltage deviation from average voltage
average voltage
Average voltage =
243 + 236 + 238
3
= 239 v
% Voltage Imbalance = 100 x
4
239
= 1.7%
IMPORTANT: Contact your local electric utility company immediately if the supply
voltage phase imbalance is more than 2%.
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