MSAT 102-122-142-162-182-202-242

LOW PRESSURE SHUTDOWN
LOW PRESSURE SHUT-DOWN
YES
Indoor unit working
correctly?
NO
Check operation
of the indoor unit ( 1 )
Check operating conditions
of the indoor unit ( 2 )
Check connection pipes
( 3 )
YES
Dewatering filter
working efficiently?
NO
Check ∆t from upstream
to downstream ( 4 )
YES
Refrigerant charge
correct?
NO
Check
superheating ( 5 )
YES
Intake valve completely
open?
NO
Check and open if
necessary
YES
Intake temperature and/or
pressure correct?
NO
Check operation
of outdoor unit ( 6 )
Unit working
Notes
1) Check:
- That there is sufficient air flow.
- That the direction of rotation of the fans is correct.
- That the exchanger is not dirty or blocked, and can provide maximum heat exchange.
- That the solenoid valve is working.
- That the thermostat is working.
2) Check that the temperature/humidity conditions of the air being treated falls within the design conditions.
3) Check that the layout and the diameter of the pipes are correctly sized (see the section on REFRIGERANT PIPES). If not,
unacceptable pressure drops may occur for the correct operation of the unit.
4) Check, using a thermometer in direct contact, the temperature upstream and downstream of the dewatering filter. If the
difference in temperature is higher than 1°C, the filter is not working efficiently or is under-rated; in both cases, replace the
filter.
5) For information on how to perform the checks, please refer to section on START-UP.
6) If the condensing pressure is below 1200kPa there may be irregular supply to the expansion device and as a
consequence too low inlet pressure.
Check that the ventilation system for the outdoor unit is working perfectly (that is, modulates or stops the fans).
49