Unit Controller Operation - York MCC Technical Manual

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 occur-
rence of a problem. Pushing the emergency switch first turns it on;
pushing it again turns if 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 dur-
ing cool or dry operation. During execution of anti-ice operation and
anti-overheating, 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 auto-
matic 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.

8 - Unit Controller Operation

Heat Pump Units Only
- Automatic mode
- Heating mode
ROOM TEMPERATURE SETTING
Press the TEMP button up or down to change the setting to the desired
room temperature. The setting range is from 16°C to 32°C.Operating
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 auto-
matically.
The Sweep button is used to control the movement of the air louvers.
By pressing the button, the louver can be set in either the fixed position
or by pressing again, it will move in a sweeping motion to distribute
the air in the room.
Applicable only for units with air sweep.
FILTER CARE AND FILTER ALARM
To keep your air conditioning unit in peak condition, the filters should
be cleaned regularly, i.e. once a month, or more frequently depending
on conditions. To do this;
-Remove the filters from the unit
-Wash them in soapy water (do not use detergent)
-Dry the filters and put them back in place on the unit.
To clean the unit casing, use a damp cloth.
The control is equipped with a filter Alarm; based on the hours of
operation, and indicated by all of the lights flashing (see the Diagnostic
Chart for details), to remind you to change the filter. To reset the alarm
press the Filter button on the remote control. If you fail to press the reset
button the alarm will automatically reset after 6 hours of operation.
CLOCK AND TIMER FUNCTIONS
To set the clock press the Clock button for at least 5 seconds, until the
Clock symbol flashes. Then use the timer buttons to set the desired
time. Finally, press the Clock button again to enter the time that has
been set.
The control is equipped with a timer that can set both start and stop
times for the unit. the operational settings that have been entered on
the control will be the ones that the control follows when it starts.
To use the timer function follow these steps;
START
1. Turn the unit on.
2. Press the start button
3. Adjust the clock display to the
desired start time
4. Press Enter
The START symbol will be shown
on the display, indicating that a
start time has been programmed.
Lights will indicate that the unit timer has been set.
STOP
1. With the unit on.
2. Press the stop button
3. Adjust the clock display to the
desired stop time
4. Press Enter
The STOP symbol will be shown
on the display, indicating that a
stop time has been programmed.
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