20
CXRC-SVX01J-EN
cause control components to malfunction and shorten
the life of relay contacts and condenser fan motors.
Voltage Imbalance
Excessive voltage imbalance between phases in a
three-phase system can cause motors to overheat and
eventually fail. Maximum allowable imbalance is 2%.
Voltage imbalance is defined as 100 times the
maximum deviation of the three voltages (three
phases) subtracted from the average (without regard to
sign) divided by the average voltage.
E
Ex
xa
am
mp
plle
e
•
L1 measured = 221 V
•
L2 measured = 230 V
•
L3 measured = 227 V
221 + 230 + 227
3
= 2.2%
N
No
otte
e:: L1 = 221 volts is the maximum deviation of the 3
voltages from the average of the 3 voltages.
Therefore, the imbalance percentage is:
100 (226 - 221)
226
= 2.2%
The 2.2 % imbalance that exists in the example above
exceeds the maximum allowable imbalance between
phases.
Table 5. CCRC/CIRC Condenser Electrical Data
Tons
Voltage
# Fans
FLA (ea.)
LRA (ea.)
MCA
MCB
20, 29, 32
200
4
4.1
20.7
17.4
20
460
4
1.8
9
7.7
15
575
4
1.4
7.2
5.9
15
35, 40
200
6
4.1
20.7
25.6
30
460
6
1.8
9
11.2
15
575
6
1.4
7.2
8.8
15
50, 60
200
8
4.1
20.7
33.8
40
460
8
1.8
9
14.8
15
575
8
1.4
7.2
11.5
15
Note:
All motors for CCRC/CIRC units are rated at 1 hp (0.7457 kW).
