Specifications

8
8 - Defrost
Defrost is handled via a defrost management electronic control
board (model with two potentiometers and 6 dip switches, see
diagram n°2). This enables defrost cycles to be initiated when
the temperature reaches -5°C at the condenser coil bend. The
end of defrost cycle set point is +10°C. The duration of the
defrost cycle varies depending on operating conditions but it is
limited to a maximum of 10 minutes. Time delay between suc-
cessive defrost cycles is 30 minutes.
The defrost cycle can be forced into action by shunting terminals
DEF on the defrost control board in the outdoor unit.
The time delay between successive defrost cycles and the maxi-
mum duration of each cycle are adjustable. If these need to be
modified, please contact YORK first for technical advice.
- Low and high pressure switch settings on units :
MOC/MOH 35-45-55-65 LP = 1.5 Bars HP = 28 Bars
Transformateur
12 34 56
ON
DEF
Depending on the climate, it may be necessary to adjust defrost
cycle start and end temperatures.
This is done with a screwdriver : adjust potentiometers 1 and 2 .
Once the adjustment has been made, Disconnect the main
power supply, wait 2 to 3 seconds then reconnect the power
supply to reset the defrost control board.
➀ Start of defrost cycle temperature
adjustment potentiometer
➁ End of defrost cycle temperature
adjustment potentiometer
③ "Dip Switches" for adjusting time
delay between defrost cycles and
maximum defrost cycle duration.
➃ Female sensor connection
⑤ Shunt these terminals to simulate a
defrost cycle
Diagram n°2 - Adjustable Defrost Control Board
Transformer