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 NO TAG (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 FRS 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 (KTU for 601 to 1200A)
575VAC, Buss FRS to 600A (KLU for 601 to 1200A)
Wire Size and Protection Devices
Table 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
mm
2
3
0.75
7
5
4
14
2.5
4
1
7
6
5
14
2.5
7
2
15
12
9
14
2.5
10
3
15
15
12
14
2.5
16
5
20
25
20
12
3.31
22
7.5
30
35
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.
