Two Speed Motor - Danfoss mcd-500 Operating Instruction

5 Application Examples

5.13 Two Speed Motor

The MCD 500 can be configured for control of dual speed Dahlander type motors, using a high speed contactor (KM1), low speed contactor (KM2) and
a star contactor (KM3).
NB!
Pole Amplitude Modulated (PAM) motors alter the speed by effectively changing the stator frequency using external winding configu-
ration. Soft starters are not suitable for use with this type of two-speed motor.
When the soft starter receives a high speed start signal, it closes the high speed contactor (KM1) and star contactor (KM3), then controls the motor
according to the primary motor settings (par. 1-1 - 1-16.)
5
When the soft starter receives a low speed start signal, it closes the low speed contactor (KM2). This closes Input A and the MCD 500 controls the motor
according to the secondary motor settings (par. 7-1 - 7-16).
1 Control voltage
2 Remote control inputs
3 Relay outputs
4 3-phase supply
5 Motor terminals
6 Remote low-speed start input
7 Remote high-speed start input
46
F1
1/L1
4
3/L2
5/L3
A4
A5
1
A6
11
KA1
16
3
15
KM1
2
KM2
17
18
S1 25
KA1
KA2
KM1
KM2
KM3
S1
21, 22, 24
MG.17.K2.02 - VLT
KM3
T4
T5
T6
KM2
T1
2/T1
T2
4/T2
T3
6/T3
KM1
E
KM3
KA2 KM2
21
24
KA1 KM3 KM1
22
KA2
6
KA1
7
Remote start relay (low speed)
Remote start relay (high speed)
Line contactor (high speed)
Line contactor (low speed)
Star contactor (high speed)
Reset contact
Relay output B
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MCD 500 Operating Instruction
5
KM1
KM3
KM2
KA1
KA2