5310923-06/02UK
Technical Manual TAR 1310 / 2310 / 4310
Page 3
Defrosting
One relay output contact is used to control a
defrosting device. Defrosting can be initiated by
the internal timer or manually. The defrost times
are set with parameters P13 thru P16.
The defrosting device is always driven from the
n/o contact of relay K2. There is no need for
interlocking the defrost with the cooling function
since with parameter P12 you select the de-
frosting mode and the controller automatically
decides on the cooling output. For information
there is parameter P26 showing the remaining
time of the momentary defrost cycle until termi-
nation by time.
Defrosting Modes (set with P12)
Refrigeration (precondition P07=1)
1=
Heater or Free Air Defrost
Relay K2 is energized and K1 is de-energi-
zed.
2=
Hot Gas Defrost
Relays K2 and K1 are energized.
Freezing (precondition P07=2)
1=
Hot Gas Defrost
Relay K2 is energized and K1 is de-energi-
zed.
2=
Heater or Free Air Defrost
Relay K2 is energized and K1 is energized
.
Manual Defrost
Parameter P30 allows you to start a defrost
cycle with the "
ñ
" key, unless the sensor is
already above termination temperature.
Defrost Termination
There are three ways for terminating a defrost
cycle:
1st:
thermal termination.
Whenever the evaporator sensor tem-
perature (P02) is warmer than the tem-
perature limit set with parameter P11,
defrosting is terminated.
2nd:
termination by (safety) time.
The time set with parameter P17 is the
maximum time a defrost cycle can last
before it is terminated automatically.
3rd:
manual terminating.
Under parameter P30 you can termina-
te a defrost cycle by pressing the "
ò
"
key.
Evaporator Fan Control
The K3 relay can be used for controlling the fan,
if it is not used for alarm purposes (see P25).
Different modes of fan operation can be selec-
ted with parameter P20.
Fan Modes
1 = Fan runs when compressor output (K1) is
on. After defrosting, the fan output is OFF
until the programmed Fan Delay Time (P21)
is complete.
.
2 = Fan runs continously, except during defrost
and Fan Delay Time (P21).
3 = Fan runs when the compressor output (K1)
is on, and during defrost. There is no fan
delay time.
A thermostatic fan control is always available.
Fan runs when sensor temperature (P02) is
below setpoint for the programmed Fan Start/
Stop Temperature (P19).
If you don't need this function, set parameter
P19 to the highest value.
The fan is always run from the n/o contact of
relay K3.
When fan delay is active, parameter P28 shows
the remaining time.