18
Table 4 — Electrical Data, Standard Motors
See Legend and Notes below.
Table 5 — Electrical Data, Alternate Motors
See Legend and Notes below.
Legend and Notes For Tables 4 and 5
UNIT
V-PH-Hz
†
VOLTAGE
LIMITS
FAN MOTOR
POWER SUPPLY
Hp (kW)
FLA
Minimum
Circuit Amps
MOCP
40RUA*25
40RUS*25
208/230-3-60
187-253
5.0 (3.73)
14.6/12.8
18.3/16.0
30/25
460-3-60
414-506
5.0 (3.73)
6.4
8.0
15
575-3-60
518-632
5.0 (3.73)
5.1
6.4
15
40RUA*28
40RUS*28
208/230-3-60
187-253
7.5 (5.59)
21.4/19.4
26.9/24.3
45/40
460-3-60
414-506
7.5 (5.59)
9.7
12.1
20
575-3-60
518-632
7.5 (5.59)
7.8
9.8
15
40RUA*30
40RUS*30
208/230-3-60
187-253
10.0 (7.46)
28.2/26.8
35.3/33.5
60/60
460-3-60
414-506
10.0 (7.46)
13.4
16.8
30
575-3-60
518-632
10.0 (7.46)
10.3
12.9
20
UNIT
V-PH-Hz
†
VOLTAGE
LIMITS
FAN MOTOR
POWER SUPPLY
Hp (kW)
FLA
Minimum
Circuit Amps
MOCP
40RUA*25
40RUS*25
208/230-3-60
187-253
7.5 (5.59)
21.4/19.4
26.9/24.3
45/40
460-3-60
414-506
7.5 (5.59)
9.7
12.1
20
575-3-60
518-632
7.5 (5.59)
7.8
9.8
15
40RUA*28
40RUA*30
40RUS*28
40RUS*30
208/230-3-60
187-253
10.0 (7.46)
28.2/26.8
35.3/33.5
60/60
460-3-60
414-506
10.0 (7.46)
13.4
16.8
30
575-3-60
518-632
10.0 (7.46)
10.3
12.9
20
LEGEND
†
Motors are designed for satisfactory operation within 10% of nominal
voltages shown. Voltages should not exceed the limits shown in the
Voltage Limits column.
NOTES:
1. Minimum circuit amps (MCA) and MOCP values are calculated in accor-
dance with NEC (National Electrical Code), Article 440.
2. Motor FLA values are established in accordance with UL (Underwriters’
Laboratories) Standard 1995.
3.
Unbalanced 3-Phase Supply Voltage
Never operate a motor where a phase imbalance in supply voltage is
greater than 2%.
Use the following formula to determine the percentage of
voltage imbalance.
EXAMPLE: Supply voltage is 400-3-50.
AB = 393 v
BC = 403 v
AC = 396 v
Determine maximum deviation from average voltage
(AB) 397 – 393 = 4 v
(BC) 403 – 397 = 6 v
(AC) 397 – 396 = 1 v
Maximum deviation is 6 v.
Determine percent voltage imbalance.
This amount of phase imbalance is satisfactory because it is below the maxi-
mum allowable 2%.
FLA
—
Full Load Amps
MOCP
—
Maximum Overcurrent Protection
% Voltage Imbalance = 100 x
max voltage deviation from average voltage
average voltage
Average Voltage =
393 + 403 + 396
3
=
1192
3
= 397
% Voltage Imbalance = 100 x
6
397
= 1.5%
IMPORTANT:
If the supply voltage phase imbalance is more than
2%, contact your local electric utility company immediately.
