Operating instructions
71
When the compressor is started up, the starter controls the
voltage applied to maintain the configured current (see
chapters 16.4 and 18.2.2).
The current limitation value set as the default is selected to
ensure certain motor starting. This value can be reduced
during the first start-up by adjusting the current limitation
value parameter configured in the starter:
• It is recommended not to reduce the parameter to a
value that corresponds to less than 45% of the LRDA
motor current.
• Motor start-up must be immediate, without any howling
noise that indicates that motor rotation was not initiated.
• Measuring the start-up current must confirm that the
effective start-up time is not more than five seconds.
Machine shut-down is controlled in the same way as for
the standard machine.
When the compressor shuts down, the oil pump ensures
post lubrication.
Do not manually shut down the machine using the main
disconnect switch or by any method that is likely to also
result in shutting down the PIC control circuit and the oil
pump power supply.
Only emergency shut-downs initiated by the machine
control must be used to carry out this type of shut-down.
If the factory-set parameters are kept, the starter is not
likely to generate motor protection alarms. These are
generated by and can be checked on the PIC control.
Internal starter fault and faults relating to its power supply
and control circuit are however generated at starter level.
In this case a fault information is reporteed to the PIC
control.
A "STARTER FAULT" indicates the problem on the PIC
display. The diagnosis must now be made by consulting the
messages displayed on the starter screen. Refer to the
manual for starter 3RW44.
NOTE: An emergency shut-down initiated by the PIC
control will automatically generate a starter fault, indicating
voltage loss at the main power circuit.
Starter input 4 (reset) is connected in parallel with input 1
(start command). In this way the starter faults must be
re-initialised at each start-up demand. If this automatic
reset does not work, it may be necessary to carry out a
manual reset:
1. Disconnect inputs IN1 and IN4 at the starter.
2. Install a jumper between terminals L+ and IN4 of the
soft starter.
3. Apply power and check on the display that the alarm
has disappeared.
4. Disconnect the jumper installed in step 2 - then
reconnect inputs IN1 and IN4 at the starter.
The voltages applied during tests with the unit energised
(isolation and dielectric) can damage the starter.
When the motor isolation is checked, the power supply
conductors between the motor and the starter must be
disconnected.
The normal maintenance operations for electrical equip-
ment apply:
• Re-tightening of the electrical connections
• Elimination of dust
• Checking for signs of localised overheating.