Specifications

c, d) The total motor cable length specified in section 4.5, General Specifications, is valid as long as the parallel cables are
kept short (less than 10 m each).
d, e) Consider voltage drop across the motor cables.
e) Be aware of the maximum motor cable length specified in Table 6.35.
e) Use LC filter for long parallel cables.
Enclo-
sure
Type
Power
Size
[kW]
Voltage
[V]
1 cable
[m]
2
cables
[m]
3
cables
[m]
4
cables
[m]
A5 5 400 150 45 8 6
500 150 7 4 3
A2, A5 1.1-1.5 400 150 45 20 8
500 150 45 5 4
A2, A5 2.2-4 400 150 45 20 11
500 150 45 20 6
A3, A5 5.5-7.5 400 150 45 20 11
500 150 45 20 11
B1, B2,
B3, B4,
C1, C2,
C3, C4
11-90 400 150 75 50 37
500 150 75 50 37
Table 6.35 Max. Cable Length for Each Parallel Cable, Depending
on Quantity of Parallel Cables.
Problems may arise at start and at low RPM values, if
motor sizes are widely different because small motors'
relatively high ohmic resistance in the stator calls for a
higher voltage at start and at low RPM values.
The electronic thermal relay (ETR) of the frequency
converter cannot be used as motor protection for the
individual motor of systems with parallel-connected
motors. Provide further motor protection by e.g.
thermistors in each motor or individual thermal relays.
(Circuit breakers are not suitable as protection).
6.4.4
Direction of Motor Rotation
The default setting is clockwise rotation with the frequency
converter output connected as follows.
Terminal 96 connected to U-phase
Terminal 97 connected to V-phase
Terminal 98 connected to W-phase
The direction of motor rotation is changed by switching 2
motor phases.
Motor rotation check can be performed using 1-28 Motor
Rotation Check and following the steps shown in the
display.
175HA036.11
U
1
V
1
W
1
96 97 98
FC
Motor
U
2
V
2
W
2
U
1
V
1
W
1
96 97 98
FC
Motor
U
2
V
2
W
2
Illustration 6.42 Motor Rotation Check Steps
6.4.5
Motor Insulation
For motor cable lengths ≤ the maximum cable length
listed in chapter 9 General Specifications and Trouble-
shooting, the motor insulation ratings listed in Table 6.36
are recommended. If a motor has lower insulation rating, it
is recommended to use a dU/dt or sine-wave filter.
Nominal Mains Voltage [V] Motor Insulation [V]
U
N
≤ 420
Standard U
LL
= 1300
420 V < U
N
≤ 500 Reinforced U
LL
= 1600
500 V < U
N
≤ 600 Reinforced U
LL
= 1800
600 V < U
N
≤ 690 Reinforced U
LL
= 2000
Table 6.36 Motor Insulation
Electrical Installation
Design Guide
MG11BC02 Danfoss A/S © Rev. 06/2014 All rights reserved. 107
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