EVCO S.p.A.
During the active defrost phases the refrigeration circuit function is inve
defrosting and to avoid both pressure imbalances and emitting freezing air into the room, both fans are switched off.
N.B.: the compressor is only switched on when the time A06 (flow alarm bypass)
guarantee airflow and avoid any possible imbalances.
10.7.1
Defrosting the refrigeration circuit
In order to determine both when it is necessary to perform a defrosting cycle and to end this, the probe located on
(
Compressor defrost probe)
is used according to the parameters governing this function (d01
According to the parameter d01 value, defrosting can be:
d01 = 0 Defrost not enabled
d01 = 1 Defrost by temperature, described below
When the compressor is active and the value detected by the probe located on the coil falls below d02, a counter begins and when this
reaches a value of d03 the defrost cycle is activated. If during counting the temperature returns to above d02 or if the comp
switched off, the count is suspended. If during counting the temperature detected by the probe falls below the value d08 defros
activated with a wait reduced to 10 seconds.
When the defrost cycle starts up the compressor is switched off for the d06 ti
After a further d06 period the compressor is reactivated for the active defrost cycle phase. The purpose of the waiting time
balance the pressures in the circuit (this could also be set
The compressor remains on until the temperature detected by the probe on the coil rises above d04, in which case the active p
comes to an end. If this condition is not achieved within the d05 time, the activ
the compressor. After this the drip phase begins, after d07 the reversing valve switches to heating status and after a furthe
compressor is reactivated in heating mode.
The diagram below shows how defrosting by temperature takes place:
d01 = 2 Defrost by compressor off, described below
To defrost the coil the compressor is switched off, in which case the fans remain on and the warm expelled air removes the ic
Compared to the last process, this one avoids the active phase of the defrost cycle (compressor on with reversing valve in the cooling
position)
d01 = 3 Defrost timed, described below
In this situation everything works as for d01=1 apart from the exit from the defrost active phase
maximum time (d05).
10.8
Constant capacity/pressure regulation
The controller can regulate the fan speed to maintain constant pressure or air capacity if the differential pressure sensor i
and not in alarm mode.
EV3 MVC & EVD MVC
| Application manual ver. 2.2
page 54 of 74
During the active defrost phases the refrigeration circuit function is inverted. To retain the heat localised on the coil that needs
defrosting and to avoid both pressure imbalances and emitting freezing air into the room, both fans are switched off.
N.B.: the compressor is only switched on when the time A06 (flow alarm bypass) has elapsed from when the fans are switched on to
guarantee airflow and avoid any possible imbalances.
Defrosting the refrigeration circuit
In order to determine both when it is necessary to perform a defrosting cycle and to end this, the probe located on
is used according to the parameters governing this function (d01-d08).
According to the parameter d01 value, defrosting can be:
d01 = 1 Defrost by temperature, described below
ssor is active and the value detected by the probe located on the coil falls below d02, a counter begins and when this
reaches a value of d03 the defrost cycle is activated. If during counting the temperature returns to above d02 or if the comp
itched off, the count is suspended. If during counting the temperature detected by the probe falls below the value d08 defros
When the defrost cycle starts up the compressor is switched off for the d06 time, at the end of which this switches the reversing valve.
After a further d06 period the compressor is reactivated for the active defrost cycle phase. The purpose of the waiting time
balance the pressures in the circuit (this could also be set to zero if a running defrost is required).
The compressor remains on until the temperature detected by the probe on the coil rises above d04, in which case the active p
comes to an end. If this condition is not achieved within the d05 time, the active defrost phase is in any case concluded by switching off
the compressor. After this the drip phase begins, after d07 the reversing valve switches to heating status and after a furthe
hows how defrosting by temperature takes place:
d01 = 2 Defrost by compressor off, described below
To defrost the coil the compressor is switched off, in which case the fans remain on and the warm expelled air removes the ic
ess, this one avoids the active phase of the defrost cycle (compressor on with reversing valve in the cooling
In this situation everything works as for d01=1 apart from the exit from the defrost active phase that is always determined by the
Constant capacity/pressure regulation
The controller can regulate the fan speed to maintain constant pressure or air capacity if the differential pressure sensor i
| Application manual ver. 2.2c | Code 1443DMVCI224
rted. To retain the heat localised on the coil that needs
defrosting and to avoid both pressure imbalances and emitting freezing air into the room, both fans are switched off.
has elapsed from when the fans are switched on to
In order to determine both when it is necessary to perform a defrosting cycle and to end this, the probe located on the coil
ssor is active and the value detected by the probe located on the coil falls below d02, a counter begins and when this
reaches a value of d03 the defrost cycle is activated. If during counting the temperature returns to above d02 or if the compressor is
itched off, the count is suspended. If during counting the temperature detected by the probe falls below the value d08 defrosting is
me, at the end of which this switches the reversing valve.
After a further d06 period the compressor is reactivated for the active defrost cycle phase. The purpose of the waiting time 2xd06 is to
The compressor remains on until the temperature detected by the probe on the coil rises above d04, in which case the active phase
e defrost phase is in any case concluded by switching off
the compressor. After this the drip phase begins, after d07 the reversing valve switches to heating status and after a further d07, the
To defrost the coil the compressor is switched off, in which case the fans remain on and the warm expelled air removes the ice.
ess, this one avoids the active phase of the defrost cycle (compressor on with reversing valve in the cooling
that is always determined by the
The controller can regulate the fan speed to maintain constant pressure or air capacity if the differential pressure sensor is configured
