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4-8 Start-up MN894
Start-up Troubleshooting The Multipurpose Control module has 7 LEDs to help diagnose problems. There is a
summary of the functions and indications on pages 2-8 and 2-9. The Multipurpose starter
was tested under load with all SCR and electronic functions checked before shipping.
Note: To test the output of a soft starter a motor must be connected, even if it is a
1/2 HP motor on a 700 HP starter. Be careful not to start large motors
repeatedly without a cooling-down period.
No Power To The Motor
1. Verify the PWR light is “ON”.
2. Verify the Start/Run light is “OFF” and confirm terminals 12-13 on the control
module are open.
3. Give the starter a start command by closing the start contact connected to
terminals 12 and 13 (verify the Start/Run light is “ON”).
If the Start/Run light is not ON, turn off power and connect terminals 12 and 13
together with a small piece of wire as the jumper. Turn power ON. The
Start/Run light should come “ON” then the MTR PWR light should come “ON”
with power going to the motor.
If this sequence occurs using the jumper, check the start circuit as to why it did
not close the terminals 12-13. If this sequence did not occur, check the voltage
going to the logic control module.
Motor Does Not Start or Motor Does Not Come Up To Speed or
The Motor Overload Overload Trips
Adjust the “CL” to the max. If the motor is still not starting, set the S1 switch for
current calibration to the max. for that control size. Setting the S1 switch to a higher
setting only effects the calibration of light bar current indicator.
Test:
Try restarting the motor while adjusting the “CL” pot during starting. During starting,
check that the incoming voltage is not dropping. If it fails to start at the max. S1
setting, record the line voltage during starting, the motor data including the lock rotor
amps and contact your local Baldor office.
Circuit Breaker is Tripping − On Power Up
The circuit breaker supplied by Baldor is a motor circuit protector (MCP). It is also
called an adjustable magnetic only breaker. This means it will only trip during a
short circuit or instantaneous overcurrent condition. Baldor also adds a shunt trip
module to the breaker. Isolate the problem by disconnecting the shunt trip circuit.
Test for short circuit before re-energizing.
Test:
After the shunt trip circuit has been disabled, apply power. Check the shunt trip light,
if it is “ON” it is detecting a shorted SCR, a loss of phase, a lack of a load or a
grounded delta system. If the SCR’s have been replaced, they may be miswired.
Do not attempt to start until the problem is found.