Instruction manual

CHAPTER 2: INSTALLATION STARTER TYPES
MM300 MOTOR MANAGEMENT SYSTEM – INSTRUCTION MANUAL 2–27
2.3.5 Inverter starter (VFD, VSD)
Figure 29: Inverter starter typical wiring
The inverter starter is used with an external inverter that ramps the motor speed up on
start and ramps it down on stop.
The B Open Contactor Control Circuit and B Welded Contactor alarms are defeated when
the inverter starter is selected.
When a start A control is received, the pre-contactor relay (if any) is picked up for the set
delay, then relay1 picks up and seals-in, picking up contactor 1M. This provides power for
the inverter to start up. Relay 2 closes after a 1 second delay, and seals-in, which signals
the inverter to ramp the motor up. When a stop control is received, the relay2 drops out,
and the inverter ramps down. When the ramp down time timer has expired, relay1 is
opened, contactor 1M drops out, cutting power to the inverter and motor.
The inverter signals the relay that it is up to speed by closing auxiliary relay MR. If the
auxiliary relay MR unexpectedly opens while running, signalling a possible inverter
problem, relay2 drops out, and the inverter ramps down if it has not done so already. An
Inverter alarm is issued, but relay1 remains closed, so contactor 1M stays picked up, and
the supply to the inverter is maintained. This is done so that the inverter has power to
retain its event records for subsequent diagnosis of the problem. Relay1 is opened
removing power to the inverter when a stop control is received, and the alarm is reset on
the next start.
A
B
C
1M 1M 1M
MOTOR
1M
Stator Thermistor
1M
Field Start
Reset
Core Balance CT
Contactor
INVERTER
MR
Motor
Running
Output
Ramp
Up
Input
MR
Field Stop
I
A
I
B
I
C
RS485 Serial Link
Ground at one point
Order Code : MM300-XEHSSCA
MM300
Low Voltage
Motor
Manager
D2
D1
D8
D7
D6
D5
D4
D3
CT Module
CT2
CT3
G/F
CT1
C1
C2
C3
C4
C5
C6
C7
C8
I/O Module- Type C
C9
C10
C11
C12
C13
C14
Aux VT
IN 1 IN 2 IN 3 IN 4 IN 5 IN 6 Com
Relay 1Relay 2
LN
+
-
Com
+
CPU
-
R
I
Surge Grd
Core
Balance
Thermistor
RS485
PSU
N
L
Consumer & Industrial
Multilin
2M
2M