Operation And Function; Ps D75 - ABB PS D75 840 Series Installation And Maintenance Instruction

5. Operation and function

5.1 PS D75 ... 840 without built-in electronic overload protection
Power on
When the softstarter is supplied with power the green LED "On" is illuminated and the board
executes a self check routine. If there are faults, the LED's "F1" and "F2" indicate these.
Start
When the start/stop input is supplied with 24V (switch is closed) the soft start routine is
executed and an increasing linear time-voltage ramp is applied to the motor,
Start voltage is selectable while the end voltage is always full voltage.
LED "R" and relay "Run" will indicate that a start has begun.
LED "T" and relay "TOR" will indicate that the start ramp has finished.
A 0,25 sec. pulse with voltage up to the current limit setting is applied to the motor at the
beginning of the ramp if the switch 'kick' is in position "YES".
A soft start can be done with a shorted thyristor if the switch "PF" is in position "No" (LED's
F1 and F2 will be illuminated, and relay "Fault" will be activated).
Stop
When the start signal is removed from the start/stop input the soft stop routine is executed
and a decreasing linear time-voltage ramp is applied to the motor. Start and stop voltages
are selectable (end voltage = initial voltage for start ramp).
LED "T" and relay "TOR" are switched off when the stop begins.
LED "R" and relay "RUN" are switched off when the stop ramp is finished
Current limit
(Start sequence) If the motor current reaches the level of the current limit, no higher voltage
is applied to the motor unless the current decreases below the limit.
During a start sequence the softstarter can't limit the current for more than 240 sec.
When the start routine is finished (ramp time + max. 240 sec) the following will occur if the
current hasn't decreased below the limit.
1. Switch "SC" is in position Yes:
The softstarter turns off
2. Switch "SC" is in position No:
Full voltage is applied to the motor
Energy saving
If the function is selected (switch "PF") a power factor optimisation commences 60 sec after the
start-ramps end, this is indicated with the LED "P".
If a slower reaction on decreased load is requested, the switch "TPF" shall be put at position "slow".
To comply with the EMC-directive 89 / 336 / EEC see instructions on page 3
High current switch off
If the current limit is overridden for more than 200 ms after "top of ramp", the softstarter turns off.
Reset via a stop signal.
The function is selectable with switch "SC", yes/no
Note: This is not complete short circuit protection, normal fuses for protecting the equipment from
short circuit are always required.
Over temperature
If the heat sink becomes overheated a temperature sensor will turn off the softstarter.
Reset via a stop signal.
Thyristor fault
If a thyristor is damaged (short circuit or open circuit) the softstarter will indicate this.
If a thyristor is shorted a start can be accomplished if the energy saving function is not
selected.
Phase loss
If one or more of the phases are missing when a start signal is applied, the softstarter will turn off
and indicate a fault. Reset via a stop signal.
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