Quick Start
Commissioning
72 Digistart IS User Guide
www.controltechniques.com Issue: 4
Possible cause/Suggested solution
Thermistor Cct
(Thermistor circuit)
The thermistor input has been enabled and:
The resistance at the input has fallen below 20 Ω (the cold resistance of most thermistors will be
over this value) or
A short circuit has occurred. Check and resolve this condition.
Related Pr: None
The Digistart IS is internally bypassed and has drawn high current during running. (The 10A protection
curve trip has been reached or the motor current has risen to 600% of the motor FLC setting.)
Related Pr: None
The motor has experienced a sharp drop in power, caused by loss of load. Causes can include broken
components (shafts, belts or couplings), or a pump running dry.
Related Pr: 5E, 6B, 16D
Unsupported option
(function not available in
inside delta)
This trip is not adjustable.
The selected function is not available (e.g. jog is not supported in inside delta configuration).
Related Pr: None
Where 'X' is 1, 2 or 3.
Internal fault (PCB fault). Contact your local supplier for advice.
This trip is not adjustable.
Related Pr: None
9.3 General faults
This table describes situations where the soft starter does not operate as expected but does not trip or give a warning.
Table 9-2 General faults
Check Input A (DI4, +24V). The emergency stop function may be active. If Pr 3A or
3F is set to Emergency Stop and there is an open circuit on the corresponding
input, the Digistart IS will not start.
The soft starter does not respond to the
START or RESET button on the keypad.
The soft starter may be in Remote control mode. When the soft starter is in Remote
control mode, the Local LED on the starter is off. Press the LCL/RMT button once
to change to Local control.
The soft starter does not respond to
commands from the control inputs.
The soft starter may be in Local control mode. When the soft starter is in Local
control mode, the Local LED on the starter is on. Press the LCL/RMT button once
to change to Remote control.
The control wiring may be incorrect. Check that the remote start, stop and reset
inputs are configured correctly (see Control Wiring on page 20 for details).
The signals to the remote inputs may be incorrect. Test the signalling by activating
each input signal in turn. The appropriate remote control input LED should activate
on the starter.
The soft starter will only execute a start command from the remote inputs if the
remote stop and reset inputs are closed.
The soft starter does not respond to a
start command from either the local or
remote controls.
The soft starter may be waiting for the restart delay to elapse. The length of the
restart delay is controlled by Pr 6G Restart Delay.
The motor may be too hot to permit a start. If Pr 5L Motor Temperature Check is set
to Check, the soft starter will only permit a start when it calculates that the motor
has sufficient thermal capacity to complete the start successfully. Wait for the motor
to cool before attempting another start.
The emergency stop function may be active. If Pr 3A or 3F is set to Emergency
Stop and there is an open circuit on the corresponding input, the Digistart IS will not
start. If the emergency stop situation has been resolved, close the circuit on the
input.
Pr 3M Local/Remote controls when the LCL/RMT button is enabled.
A reset does not occur after an
Auto-Reset, when using a remote
two-wire control.
The remote 2-wire start signal must be removed and reapplied for a re-start.
Remote start/stop command is overriding
Auto Start/Stop settings when using
remote two-wire control.
Auto Start/Stop function should only be used in Remote mode, 3 and 4-wire control.
Non-resettable Thermistor Cct trip, when
there is a link between the thermistor
input TH1, TH2 or when the motor
thermistor connected between TH1, TH2
is permanently removed.
The thermistor input is enabled once a link is fitted and short circuit protection has
activated.
- Remove the link then load the default parameter set. This will disable
the thermistor input and clear the trip.
- Place a 1k2 resistor across the thermistor input.
- Turn thermistor protection to 'Log only' (Pr 16K).