Carel MPXPRO User Manual page 37

1. Heater defrost (d0 = 0, 2, 4): duty cycle
The duty cycle refers to the default values of parameters F2 and F3. The
valve can be opened to the initial value set for cP1 for a period equal to
Pdd.
refrig pump
down
ON
SV/CMP
OFF
ON
EEV
OFF
ON
FAN
F2
OFF
ON
DEF
OFF
Fig. 5.k
Key
t Time SV/CMP Solenoid / compressor
FAN Fan EEV Electronic expansion valve
Valve position maintenance time after
DEF Defrost Pdd
defrost
drip dripping post drip post dripping
2. Hot gas defrost (d0 = 1, 3): duty cycle
The duty cycle refers to the default values of parameters F2 and F3.
The valve can be opened to the initial value set for cP1 for a period equal
to Pdd.
refrig pump
down
ON
SV/CMP
OFF
ON
EEV
OFF
ON
FAN
F2
OFF
ON
DEF
OFF
Key
t Time SV/CP
FAN Fan EEV
DEF Defrost Pdd
drip dripping post drip
The pump down phase is the period in which the evaporator is emptied
of liquid refrigerant, and can be disabled by setting dH1=0. See the
chapter on Advanced functions. The operation of the fan during the
Pump down and Hot gas phases depends on parameters F2 and F3.
During the dripping and post-dripping phases, it is always off .
res drip post drip refrig
(dd) (Fd)
cP1
F3
Pdd
hot gas drip post drip refrig
(dd) (Fd)
cP1
F3
Pdd
Fig. 5.l
Solenoid / Compressor
Electronic expansion valve
Valve position maintenance time after
defrost
post dripping
3. Multiplexed hot gas defrost (d0 = 5, 6) : duty cycle
The duty cycle refers to the default values of parameters F2 and F3.
The valve can be opened to the initial value set for cP1 for a period equal
to Pdd.
refrig
ON
SV
OFF
ON
EEV
OFF
ON
SSV
OFF
ON
HGSV
t
OFF
ON
ESV
OFF
ON
FAN
OFF
Key
t Time
FAN Fan
SSV Suction valve
ESV Equalizing valve
drip dripping
37
pump hot gas drip post drip
down (dd)
dHG dHG
F2
Fig. 5.m
SV Solenoid
EEV Electronic expansion valve
HGSV Hot gas valve
Valve position maintenance time
Pdd
after defrost
post drip post dripping
MPXPRO - + 0300055EN rel. 1.1 30/08/10
ENG
refrig
(Fd)
dHG dHG
t
Pdd