McQuay WDC

Product Manual PM WSC/WDC 47
Electrical Data
Centrifugal compressor motors have been redesigned to increase efficiencies well into the 90% range. This
design change is particularly important since it represents a motor characteristic that directly impacts the
system’s watt-hour meter. In addition, the motor efficiency, unlike power factor, is a design characteristic that
cannot be improved on the job.
Motor and Voltage Code
The typical unit model number below displays the three digits used to identify the motor and voltage codes:
WSC 126K BS 72 R
The motor described by motor and voltage code letters will determine the maximum kW, locked rotor amperes,
power factor and voltage found in the Motor Data Tables.
Wiring and Conduit
Wire sizes should comply with local and state electrical codes. Where total amperes require larger conductors
than a single conduit would permit (limited by dimensions of motor terminal box), two or more conduits may be
used. Where multiple conduits are used, all three phases must be balanced in each conduit. Failure to balance
each conduit will result in excessive heating of the conductors and unbalanced voltage.
An interposing relay may be required on remote mounted starter applications when the length of the conductors
run between the chiller and starter is excessive.
Note: On WDC dual compressor units, dual power leads are standard, requiring separate power leads properly
sized and protected to each compressor starter. Separate disconnects must be used.
Motor Data
10⇒ Motor nominal horsepower ÷ 10
A⇒ Compressor that motor is used on; A = 050, B = 063 to 087, C = 100 to
126
60 Hertz
Nameplate Volts 200 208 220 230 240 380 440 460 480 575 2400 3300 4160 6600
Voltage Code N B P V W U A R S D M C L 2Motor
Code
Min/Max Volts
180/
220
187/
229
198/
242
208/
253
216/
264
342/
418
396/
484
414/
506
432/
528
518/
633
2160/
2640
2970/
3630
3744/
4575
5940/
7260
Max kW
87
87
87
86
86
86
87
86
86
86
10
Locked Rotor Amps
1104
1148
947
990
1033
613
473
495
517
405
A
Power Factor
.90
.90
.90
.90
.89
.90
.90
.90
.89
.89
Max kW
111
111
111
111
110
111
111
111
110
111
13
Locked Rotor Amps
1548
1610
1291
1350
1409
832
646
675
704
544
A
Power Factor
.89
.88
.89
.89
.87
.88
.89
.89
.87
.88
Max kW
124
123
124
124
124
124
124
124
123
123
15
Locked Rotor Amps
1813
1886
1469
1536
1603
890
735
768
801
610
A
Power Factor
.87
.86
.88
.87
.86
.88
.88
.87
.86
.87
Max kW
145
145
146
145
145
145
146
145
145
145
18
Locked Rotor Amps
2850
2975
2294
2402
2517
1617
1147
1201
1259
1022
B
Power Factor
.89
.87
.90
.89
.87
.87
.90
.89
.87
.88
Max kW
141
141
142
19
Locked Rotor Amps
179
223
83
B
Power Factor
.88
.80
.87
(Continued next page)
Motor Code
Voltage Code