Functions - York YLHA 50 User Manual

1 User manual
1.2 Operating instructions µC2 (YLHA 50, 60 and 80)

1.2.14 Functions

Alarm reset
Pressing the UP and DOWN keys for 5 seconds cancels alarms present in the memory. At the same
time, the alarm message disappears from the display and the alarm relay is deactivated.
Forced defrost (heat pumps)
Pressing the SEL and UP keys simultaneously for 5 seconds activates forced defrost of the unit.
Clearing hour counters
While reading compressor or pump (c10, c11 and c15) operating hours, said counters can be cleared
by pressing the UP and DOWN keys simultaneously.
Pump operation
4 operating modes can be selected in accordance with the value given to parameter H5. H5=0 (pump
disabled). H5=1 (pump permanently on), H5=2 (pump ON controlled by the regulator or in parallel with
the compressor), H5=3 (pump goes on and off at regular intervals, independent of compressor operation)
(parameters c17 and c18).
Calibration of sensors
If necessary, sensors can be calibrated by using parameters /13, /14, /15, /16, /19 and /20. See Table
Parameters relating to sensors, see on page 12 .
Remote ON/OFF
A remote ON/OFF inlet can be connected between terminals D5 and B on the connecting strip. To activate
said inlet, a value of 1 should be given to parameter H07 (H07= 1). With this inlet open the unit is OFF;
when closed, the unit is ON. This option does not disable the ON/OFF function of the keyboard.
Remote COOL/HEAT
A remote COOL/HEAT inlet can be connected between terminals D2 and B on the connecting strip. To
activate said inlet, a value of 1 should be given to parameter H06 (H06= 1). With this inlet open the unit
is in HEAT; when closed, the unit is in COOL. This function disables the COOL/HEAT function of the
keyboard.
Partialisation of compressors in (HP Prevent) high pressure
This function is activated if P04 = 1. If for any reason the high pressure is near the disconnecting point
(P18-0.5 bar), this control deactivates one of the compressors and waits 10 seconds. After this interval,
if the alarm persists, the unit will stop. If, on the other hand, the alarm disappears, the unit will continue
to operate with one single compressor. In this situation, the message PC1 appears on screen. This
condition will remain activated until the pressure drops below the F5 + F6 value. In this case, the unit
recovers the previously deactivated compressor.
24