3-6 Receiving & Installation MN715
AC Main Circuit
Power Disconnect A power disconnect should be installed between the input power service and the control
for a fail safe method to disconnect power. The control will remain in a powered-up
condition until all input power is removed from the control and the internal bus voltage is
depleted.
Protective Devices Recommended fuse sizes are based on the following:
115% of maximum continuous current for time delay.
150% of maximum continuous current for Fast or Very Fast action.
Note: These general size recommendations do not consider harmonic currents or
ambient temperatures greater than 40°C.
Be sure a suitable input power protection device is installed. Use the recommended
circuit breaker or fuses listed in tables 3-2 through 3-4 (Wire Size and Protection
Devices). Input and output wire size is based on the use of copper conductor wire rated
at 75 °C. The table is specified for NEMA B motors.
Circuit Breaker: 1 phase, thermal magnetic.
Equal to GE type THQ or TEB for 230VAC
3 phase, thermal magnetic.
Equal to GE type THQ or TEB for 230VAC or
Equal to GE type TED for 460VAC and 575VAC.
Fast Action Fuses: 230VAC, Buss KTN
460VAC, Buss KTS to 600A (KTU for 601 to 1200A)
575VAC, Buss KTS TO 600A (KTU for 601 to 1200A)
Very Fast Action: 230VAC, Buss JJN
460VAC, Buss JJS
575VAC, Buss JJS
Time Delay Fuses: 230VAC, Buss FRN
460VAC, Buss FRS to 600A (KLU for 601 to 1200A)
575VAC, Buss FRS to 600A (KLU for 601 to 1200A)
Wire Size and Protection DevicesTable 3-2 230VAC Controls (3 Phase) Wire Size and Protection Devices
Control Rating Input Breaker Input Fuse (Amps) Wire Gauge
Amps HP Input Breaker
(Amps) Fast Acting Time Delay AWG mm2
3 0.75 5 4 14 2.5
4 1 6 5 14 2.5
7 2 10 9 14 2.5
10 3 15 12 14 2.5
16 5 25 20 12 3.31
22 7.5 30 30 10 5.26
28 10 40 45 35 8 8.37
42 15 60 70 60 6 13.3
54 20 70 80 70 6 13.3
68 25 90 100 90 4 21.2
80 30 100 125 110 3 26.7
104 40 150 175 150 1 42.4
130 50 175 200 175 1/0 53.5
145 60 200 225 200 2/0 67.4
192 75 250 300 250 4/0 107.0
Note: All wire sizes are based on 75°C copper wire. Higher temperature smaller gauge wire may be used per NEC
and local codes. Recommended fuses/breakers are based on 40°C ambient, maximum continuous control
output current and no harmonic current.