Application guidelines
20
FRCC.PC.021.A5.22
Operating conditions
2 status LEDs are present on OCS:
LED 2 displays the motor protection status.
Compressor models PSH051-064-077 are
delivered with a pre installed motor protection.
This device provides efficient and reliable
protection against overheating, overloading as
well as phase loss/reversal.
The motor protection is effective thanks to PTC
sensors embedded in the motor winding and
OCS control. The close contact between sensors
and windings ensures a very low level of thermal
inertia.
The motor temperature is constantly measured
by a PTC thermistor loop connected to the OCS.
If any thermistor exceeds its response
temperature, its resistance increases above the
trip level (4,500 Ω) and the output relay then trips
– i.e. contacts M1-M2 are open.
After cooling below the response temperature
(resistance < 2,750 Ω), a 5 minutes time delay is
activated. After this delay has elapsed, the relay
is once again pulled in – i.e. contacts M1-M2
are closed. The time delay may be cancelled by
means of resetting the mains.
Compressor protection
Overheating/overloading
protection
LED1 (red) displays the
board general status
LED2 (yellow) displays the
motor protection status
LED1 displays the board general status with the following blinking codes
LED 2 Status display
Blinking sequence
Status
continuous on
Ready for starting
0.1secON/ 0.3secOFF
for 5 min 0.1secON/0,7secOFF.
ALARM 22
: Motor overheating
ACTION
: STOP COMPRESSOR
RESTART
: 5min Delay after motor cooling.
LED 1 Status display
Blinking sequence
Status
Reset
continuous on
OCS powered and stable
NA
slow blinking
1.5secON/1secOFF
Warning without requirement
for immediate action.
Come back to stable status
by automatic or manual reset.
fast blinking
0.5secON/0.5secOFF
ALARM
, requires
maintenance intervention
Come back to stable status
by specialist intervention
