Carrier 30HR090 - Unbalanced 3-Phase Supply Voltage

Table 2 - Electrical Data
COMPLETE CHILLER
VOLTS
NOM
208/230

460
575
COMPRESSOR USAGEt
Supply
Range*
187-253
414-508
518-632
Circuit 1

Circuit 2
Com pressor No.
UNIT 30
MKW
MCA
MFA
MCA
MFA
MCA
MFA
1
2
3
070
73.4
241
300
108
125
93
125
2150
A150
6175
080
82.3
270
350
119
150
105
125
6175
A150
6175
090
91.2
299
350
130
150
117
150
6175
F175
6175
100
103.8
148
175
129
150
6175
A150
6175
A150
HR
,
159
175
141
175
110
112.7

18

-
7
-
-
-
-
6175
F175
6175
A150
120
121.6

207
170
200
153
175
6175
F175
6175
F175
140
155.8

267
6299
F175
6299
F175
160
190.0

315:
6299
F299
6299
F299
070
84.7

304
400
128
175
110
150
2250
A250
.

6275
-
080
95.3

334
400

144
175
122
150
6275
A250
6275
-
090
105.9

364
400 \

160
200
134
175
6275
F275
6295
-
100
120.0
177
225
151
175
6275
A250
6275
A250
HS
110
252
130.6

222
183
-
225
163
_ 200
6275
F275
6275
A250
120
141.2

252
209
250
175
200
6275
F275
6275
F275
140
176.8
6299
F275
6299
F275
160
212.4
6299
F299
6299
F299
INDIVIDUAL COMPRESSORS
VOLTS
208/230
460
575
UNIT 30
Comp
06E$r
KW
RLA
LRA
MTA
RLA
LRA
MTA
RLA
LRA
MTA
HR '
070
thru
120
150
175
21.5
30.4
63
92
283
446
88
128
29
40
142
223
40
56
24
36
98
164
33
50
140,
160
175
299
30.4
47.5
92
140
446
690
128
196
40
65
223
345
56
90
36
53
164
240
50
73
HS
070
thru
120
250
275
24.7
35.3
82
112
345
506
114
156
33
49
173
253
45
68
29
41
120
176
40
57
140,
160
275
299

-
35.3
53.1
112
159
506
690
156
222
49
68
253
345
68
95
41
59
176
240
57
82
EN
Two electrical power circuits are required. A separate
entrance and a terminal block are provided for each
circuit. For 30HR,HS110 units, upper value is circuit 1
and lower value is circuit 2. For other size units, the value
shown is same for both circuits.
KW -
Maximum Power Input (each compressor)
LRA -
Locked Rotor Amps
MCA -
Minimum Circuit Amps. Complies with NEC.
Section 430-24.
MFA -
Maximum Fuse Amps
MKW -
Maximum Unit Power Input
MTA -
Must Trip Amps (compressor circuit breaker)
RLA -
Rated Load Amps
*Supply Range -
Units are suitable for use on electrical systems
where voltage supplied to the unit terminals is not below or above
the listed range limits.
tCircuits and compressors are numbered from left to right when
viewed from the front of the unit. Prefix: 2, 6 - has unloader,
A, F - no unloader.
Unbalanced 3-Phase Supply Voltage -
Never
operate a motor where a phase unbalance in supply
voltage is greater than 2%.
Use the following
formula to determine the % voltage unbalance:
% Voltage Unbalance =
100 x
max voltage deviation from average voltage
AB = 243 volts
BC = 236 volts
AC = 238 volts
Average Voltage =
243 + 236 + 238
= 239 volts
3
$Models 150 and 250 are 4-cylinder compressors models 175,
275 and 299 have 6 cylinders.
NOTES:
1.
Compressor motors on all units are thermally protected by over-
temperature sensors in the discharge side of the compressor.
2.
Maximum allowable phase unbalance: volts, 2%; amps, 10%.
3.
Maximum incoming wire size:
For all voltages:
500 MCM for 30HR,HS070-160
4.
To reduce demand loading during intermediate seasons, 3-
compressor units (070-090) have a manual switch (CS) to cut
out compressor No 2. On 4-compressor units (100-160), a
switch (CS) is provided to cut out compressor No. 4.
5.
All units have a compressor starting sequence transfer switch.
Three-compressor units:
switch position no. 1,
3-1-2;
switch
position no. 2,
1-3-2.
Four-compressor units:
switch position no. 1,
3-1-2-4;
switch
position no. 2,
1-3-2-4.
Determine maximum deviation from average
voltage:
(AB) 243 - 239 = 4 volts
(BC) 239 - 236 = 3 volts
(AC) 239 - 238 =
Maximum deviation is 4 volts. Determine
voltage unbalance:
% Voltage Unbalance = 100 x

23
9
= 1.7%
This amount of phase unbalance is satisfactory
as it is below the maximum allowable of 2%.
average voltage
Example: Supply voltage is 240-3-60
A B C
4