Unit Controller Operation - York MKL/MKM 25 Technical Manual

10 - UNIT CONTROLLER OPERATION

EMERGENCY OPERATION
Units are equipped with a switch to run in emergency operation mode. The switch is on the infrared receiver board
where the LED lights are located, or in the case of wall mount units it can be accessed by opening the front grill. This
switch is used for manual operation upon expiration of service life of remote control batteries, or upon occurrence of
a problem. Pushing the emergency switch first turns it on; pushing it again turns it off (toggle action). During emergency
operation, the remote controller cannot be used and the power LED light will flash in intervals, while the other LED
lights will indicate the operation of the Diagnostic Codes.
In Emergency Operation in cool mode, the temperature will be set at 24°C and the fan on Auto. In heating the unit will
switch to auto mode at a temperature set point of 24°C and the fan will run on auto mode.
AUTO RESTART FUNCTION
Upon suspension of electrical power supply during operation for any reason, when supply of power resumes the unit
operation will restart automatically according to all parameters set before the suspension of power.
ANTI-ICE AND ANTI OVERHEATING
This feature is used to prevent the evaporator unit from freezing during cool or dry operation. During execution of
entice operation and antioverheating, the compressor will stop operating and the fan will continue to run until the coil
temperature reaches predetermined set points, at which time the unit will resume normal operation.
LOW VOLTAGE
The feature is used to protect against any damage to the unit caused by fluctuation of voltage. If voltage is lower than
the lower limit for approximately 10 seconds or longer, compressor operation will be temporarily stopped. Normal
operation will resume when the voltage returns above the set limit for a minimum of 10 seconds. If the time elapsed
is less than 3 minutes then the compressor start up will be delayed until 3 minutes has passed.
SYSTEM OPERATION MODE SELECTION
There are five different operating modes;
Cool Only and Heat Pump Units
- Cooling mode
- Dry mode
- Fan mode (only on Cooling units)
The required mode can be selected by pressing the System button until the corresponding mode symbol appears on
the display. In automatic mode the unit operates automatically between Cool and Heat modes based on the change
in the room temperature and the temperature set point entered on the control.
ROOM TEMPERATURE SETTING
Press the TEMP button up or down to change the setting to the desired room temperature. The setting range is from
18°C to 32°C. Operation the unit below 18°C may result in the coil freezing.
FAN SPEED AND LOUVER POSITION SETTING
Low - Medium - High speeds are available. Press the FAN button for the desired air flow. The FAN symbol shows the
speed that has been selected.
Automatic fan speed is available in Cooling and Heat modes only.
When the dehumidification mode is used, the fan speed is set automatically.
14
CASSETTE
03_MKL-MKM.p65
Heat Pump Units Only
- Automatic mode
- Heating mode
14 13/6/02, 11:08 am
YORK CASSETTE (EN) 035T76015-000