ABB PST72 Installation And Commissioning Manual

Trouble shooting
Chapter 11
180
1SFC132003M0201
11:3 General problems and faults
Status Possible cause Solution
Motor humming / starts without
given start signal.
Shorted thyristor.
By-pass contactor stuck in
closed position.
• Check and replace.
• Check and correct the reason.
Bad motor sound during start
and operation.
Inside Delta connection wrong. • Check and correct the wiring.
Bad motor sound during stop. Wrong ramp time for stop. • Try different ramp times (some adjust-
ments can be necessary for best
result).
Motor does not start when giving
start command using the hard-
ware inputs.
Control wiring not correct
Start and stop command given
at the same time.
Keypad is in Local Control menu.
• Check connections for start and stop.
• Check that start and stop command is
not given at the same time.
• Check that the keypad is not in Local
Control menu.
• Check that parameter Fieldbus Ctrl is
set to No.
Motor does not start when giving
start command using the fieldbus
communication.
Setting of fieldbus parameter
wrong.
• Check that parameter Fieldbus Ctrl is
set to Yes.
• Check that bit "Enable" is used.
• Check that programmable inputs have
correct settings.
Displayed current in LCD does
not correspond to motor current.
Inside Delta connection. • If the softstarter is connected Inside
Delta, the current displayed is 58%
( ) of the motor current.
Displayed current in LCD is not
stable.
The motor is too small.
The load on the motor is too
small.
(current is out of measuring
range).
• Check that the softstarter corresponds
to the motor size.
• Increase the load if possible.
• Check that softstarter and motor sizes
correspond.
Loading of parameters does
not work properly.
Fieldbus settings. • See chapter Fieldbus for actual field-
bus type.
13()⁄

ABB PST72 Specifications

General

Brand	ABB
Model	PST72
Category	Controller
Language	English