Lennox EMEA DUO CU Série Notice Technique D'installation page 30

441
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In the table below, you will find the abbreviations of the different types of pressure switches and an explanation
of their usefulness (note that the pressure switches HPS1 and HPS2 are not adjustable and must be replaced by
those provided in spare parts for operation in R134A, R450 and R513)
Designation
General safety low pressure switch
Compressor safety low pressure switch
Compressor safety high pressure switch
Regulated low pressure switch
Regulated high pressure switch
Low pressure frame switch
High pressure frame switch
GB
Abbreviation
Shuts down all compressors via
BPG
common relay for all compressors
Shut off the compressor on which
BPS
it is connected
Shut off the compressor on which
HPS
it is connected
Regulates the operation of the
compressor on which it is
connected in emergency mode in
BPR
the case of an installation with PLC
(Programmable Logic Controller)
or pressostatic operation
Regulates the operation of fan
condensers in emergency mode in
HPR
the case of an installation with PLC
or pressostatic operation
Engages the rescue mode after a
delay during a malfunction of the
BPE
PLC (non-functioning of the
Engage the rescue mode
immediately when the PLC
HPE
malfunctions (non-functioning of
the condenser fans)
30/72 -
Function
compressors)
Setting
Its cut-off value must be
equal to the minimum
operating value of the
compressor
Its cut-off value must be
2°C higher than the
maximum operating
value of the compressor
Its cut-off value must be
2°C lower than the
maximum operating
value of the compressor
It must enable the
operation of the
compressor for the
nominal value of low
pressure
It must enable the
operation of the fan
condenser for the
nominal value of high
pressure
Its threshold value must
be equal to the lowest
temperature produced
Its threshold value must
be equal to the
condensation set point
temperature + 5 ° C
DUO CU