Section 5

Troubleshooting

Trips

The trip display message is briefly displayed repeatedly (flashing) on the

 

screen to warn of an imminent trip. Some trip conditions need time to take

 

effect. The warning can allow you time to resolve the situation. The

 

message will clear when you use the keypad, but after a short time will

 

reappear until the problem is resolved, or the drive trips.

 

When a trip occurs, the control’s power stage is immediately disabled

 

causing the motor and load to coast to a stop. The trip is latched until action

 

is taken to reset it. This ensures that trips due to transient conditions are

 

captured and the Inverter is disabled, even when the original cause of the

 

trip is no longer present. At this time, the activated alarm is displayed on

 

the keypad display.

 

 

Reset a Trip

 

 

All trips must be reset before the Inverter can be re–enabled. A trip can

 

only be reset once the trip condition is no longer active, i.e. a trip due to a

 

heatsink over–temperature will not reset until the temperature is below the

 

trip level. You can reset the trip as follows:

 

1.

Press the

(STOP) key to reset the trip and clear the alarm from

 

 

the display.

 

 

2.

Remove and then re–apply the RUN command and the drive will run

 

 

normally.

 

 

Success is indicated by either

or the Local Setpoint being displayed.

Display

Trip Message and Meaning

Possible Reason for Trip

 

DC LINK HIGH

The supply voltage is too high

 

The Inverter internal dc link

Trying to decelerate a large inertia load too

 

voltage is too high

quickly; DECEL TIME time too short

 

 

The brake resistor is open circuit (400V unit

 

 

only)

 

DC LINK LOW

DC LINK low trip. Supply is too low/power down

 

OVERCURRENT

Trying to accelerate a large inertia load too

 

The motor current being drawn

quickly; ACCEL TIME time too short

 

from the Inverter is too high

Trying to decelerate a large inertia load too

 

 

quickly; DECEL TIME time too short

 

 

Application of shock load to motor

 

 

Short circuit between motor phases

 

 

Short circuit between motor phase and earth

 

 

Motor output cables too long or too many

 

 

parallel motors connected to the Inverter

 

 

FIXED BOOST level set too high

 

HEATSINK

The ambient air temperature is too high

 

OVERTEMPERATURE

Poor ventilation or spacing between Inverters

 

Drive heatsink temperature >

 

 

100ºC

 

 

 

A current of less than 1mA is present when

 

 

4–20mA setpoint is selected – look for a wire

 

 

break

MN735

Troubleshooting 5–1

Page 44
Image 44
Baldor MN735 manual Section Troubleshooting, Trips, Reset a Trip