Calorex monitair DH44 Series Owners & Installation Manual page 19

VOLT FREE TERMINALS
Six pairs of Volt Free terminals are present on th e printed circuit board. Five of th em can
be used to connect th e DH44/66 to a BMS system or to lamps to monitor th e status of th e
dehumidifi er.
The Maximum Inductive Load for th ese connections is 3A.
Compressor running.
Zero volt connection is closed when th e compressor is running.
Fan running.
Zero volt connection is closed when th e fan is running.
LP Fault.
Zero volt connection is closed when th e Low Pressure switch is open.
HP Fault.
Zero volt connection is closed when th e High Pressure switch is open.
If a volt free common fault is required for th e LP and HP switches, th ey can be linked in
parallel. See diagram below.
LPHW
When th e Dehumidifi er is fi tted with an LPHW valve th e Zero volt connection is closed when
heating is required. Also known as th e Boiler Go Signal.
External fan.
Not used on th is type of dehumidifi er.
ZERO VOLTS
EXT FAN LPHW
ZERO VOLTS
EXT FAN LPHW COMP
ZERO VOLTS
COMP FAN LP
FAN LP HP
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HP
SD496251 iss 9