Operating States - AuCom MVE Series User Manual

7.5

Operating States

Start and Run States
The MVE soft starter has six operating states, and performs the following actions in each state:
1 2
Starter State
1 Not ready
2 Ready
3 Pre-start checks
4 Starting
5 Running
6 Stopping
Trip States
The starter's response to a trip depends on the starter's state when the trip occurs.
Trip while starting (bypass contactor not yet closed)
•
State
Not ready
Ready
Start command received
Pre-Start Checks
Starting
Trip command
Tripped
Reset command received
Trip while running (bypass contactor closed)
•
State
Not ready
Ready
Start command received
Pre-Start Checks
Starting
Full conduction
Running
Trip command
Tripped
Reset command received
Instantaneous Overcurrent Stage 2 trip
•
The main contactor opens immediately, regardless of the starter's state.
a
b c
3 4
Starter actions
Control power is on. The starter may be in Restart Delay mode or waiting for the motor to
cool down before allowing a start.
The starter is initialised and waiting for a start command.
A start command has been received (a). The main contactor closes (b) and the starter
performs a series of internal and external checks.
The starter ramps the SCRs up to full conduction and closes the bypass contactor (c).
The motor is running normally.
A stop command has been received (d). The starter opens the bypass contactor (e), ramps
the SCRs down to no conduction, then opens the main contactor (f).
Function
Perform system checks.
Wait for start command.
Main contactor closes.
Perform connection checks.
Ramp up SCR firing angles.
Turn SCRs off then open main contactor.
Wait for reset command.
Trip cleared and starter returns to Not Ready state or Ready state.
Starter action
Perform system checks.
Wait for start command.
Main contactor closes.
Perform connection checks.
Ramp up SCR firing angles.
SCRs at 100% conduction. Verify current is < 120% FLC then close bypass contactor.
Normal motor run state (bypassed mode).
Open bypass contactor. Turn SCRs off then open main contactor.
Wait for reset command.
Trip cleared and starter returns to Not Ready or Ready state.
d
e f
5 6
MVE User Manual (710-17074-00H) |
OPERATION
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