Low Pressure Cut Out - Lennox CLIMATIC 50 User Manual

LOW PRESSURE CUT OUT

Description
The low pressure cut out limit depends on the type of refrigerant which is inside the circuit and is defined as
following:
R407C 1,5 bar abs. (Or –28°C Vapour Saturated Temperature).
One compressor on circuit n does not work for 2 minutes and in the case of a unit with low ambient kit and
Thermostatic Expansion Valve, the TXV bypass valve has been closed for 1 minute, but the low pressure is
too low.
NOTE: Only units with thermostatic expansion valves and Low ambient kit options are fitted with TXV
bypass.
Action
If the Low Pressure of a circuit is below the safety limit for more than an hour, then the considered
circuit is not allowed to start again.
This circuit is shut down immediately.
A fault signal is shown on the display.
The remote fault signal is delayed by 6 minutes.
Reset
Automatic reset of the fault signal as soon as the low pressure moves above the "CUT OUT" limit
If the low pressure fault is activated more than three times during the same day, the fault signal is locked out
and must be reset manually.
The auto reset limits are detailed below
R407C 2.5 bars abs. (or –16°C saturated vapour temperature).
Note: Fault counter is cleared and reset every day at 10 am, as long as the maximum number of faults
has not been reached.
Possible causes
Not enough refrigerant in the circuit.
Faulty expansion valve.
Dirty filter drier.
Faulty low pressure sensor.
CLIMATIC 50 user manual – Chillers ranges
n7
Fault Code: 1
Adjust the refrigerant charge
Check the good working of the expansion valve.
Change the filter drier
Replace the low pressure sensor.
Solving the problem
CL50-CHILLERS/IOM/1105-E
FAULT CODES
31
31