(a)
(b)
(c)
(f )
(g)
(h)
10sec
Figure 15: Short cycle protection
(g)
(b)
(c)
(a)
(f )
(h)
CC-000212
Start signal is given by the unit controller
Compressor started
Compressor stop requested by the unit controller
Start signal is given by the unit controller
Start Command is ignored. Start delay warning (A96)
Compressor starts after the timer interval between starts (10s) has elapsed.
Interval between stop and start
Drive alarm
Drive alarms can be a problem with the drive itself or with the compressor. It is necessary to identify the alarm
code to determine appropriate trouble shooting actions.
Drive alarms will trip the compressor; therefore, the unit controller must get feedback that the drive is in a fault
condition.
The feedback is typically via modbus.
By default, alarms are reset automatically after 30s and the compressor restarts.
If the
specified
number of automatic resets (10x) is reached within 10 minutes, the drive enters manual reset mode.
Manual reset is via [OFF] key on the LCP or via Modbus. After the manual reset is performed, the drive reset mode
returns to automatic reset.
If an alarm cannot be reset, the reason may be that its cause has not been
rectified,
or the alarm is trip locked.
Trip lock
Alarms that are trip-locked
offer
additional protection, meaning that the mains supply must be switched
off
before
the alarm can be reset. After being switched back on, the frequency converter is no longer blocked and may be
reset as described above once the cause has been
rectified.
© Danfoss | Climate Solutions | 2023.08
AB392939083370en-000202 | 29
Scroll compressors, VCH115 | Frequency converter