Minimum Current Ampacity (MCA)
Calculation
1.25 x FLA of larger hp motor or compressor = _____
1.25 x heater FLA
= + _____
Sum of all other motors FLA
= + _____
Wheel drive motor and standard controls FLA = + _____
Indirect gas heater FLA
= + _____
Calculated total MCA
= _____
Maximum Overcurrent Protection (MOP)
Calculation
2.25 x FLA of larger hp motor or compressor = _____
Electric heater FLA
= + _____
Sum of all other motors FLA
= + _____
Wheel drive motor and standard controls FLA = + _____
Indirect gas heater FLA
= + _____
Calculated total MCA
= _____
Actual MOP (from Table F6)
= _____
Finding the Actual MOP Value
From the calculated MOP value, select the next smallest
value of protection from the Standard Overcurrent Protec-
tion chart below to get the actual MOP value (maximum
value of overcurrent device).
IMPORTANT
If this method leads to an actual MOP value being
smaller than the calculated total MCA, then a larger value
must rather be selected, such that the actual MOP is at
least equal to the calculated total MCA.
Table F5: Dual Circuit Compressors
For Dual Circuit On/Off Units
6 tons
Two 3 ton on/off compressors
8 tons
Two 4 ton on/off compressors
10 tons
Two 5 ton on/off compressors
12 tons
Two 6 ton on/off compressors
14 tons
Two 7 ton on/off compressors
16 tons
Two 8 ton on/off compressors
21 tons
Two 10 ton on/off compressors
For Dual Circuit Variable Refrigerant Control (VRC)
®
Units
6 tons
One 3 ton on/off compressor
One 3 ton VRC compressor
8 tons
One 4 ton on/off compressor
One 4 ton VRC compressor
10 tons
One 5 ton on/off compressor
One 5 ton VRC compressor
12 tons
One 6 ton on/off compressor
One 6 ton VRC compressor
14 tons
One 7 ton on/off compressor
One 7 ton VRC compressor
16 tons
One 8 ton on/off compressor
One 8 ton VRC compressor
21 tons
One 10 ton on/off compressor
One 10 ton VRC compressor
Table F6: Standard Overcurrent Protection
3
40
250
4
45
300
5
50
350
6
60
400
7
70
450
8
80
500
9
90
600
10
100
650
12
110
700
15
125
750
20
150
800
25
175
850
30
200
900
35
225
1,000
VCES-VHC-IOM-1F – VHC-36, -42 & -50
41
