Mitsubishi Electric PQHY-P200YLM-A Service Handbook page 190

[ VII Control ]
(2) Heat source unit (cooling only, heating only, cooling main and heating main modes)
"HO" / "PLEASE WAIT" blinks
on the remote controller
Protection function
self-holding cancelled.
1. 52C1 4-way valve OFF
2. Inverter output 0Hz
3. All solenoid valves OFF
*Note 1. For about 3 minutes after power on, search for the indoor unit address, for the remote controller address,
and for the group information will start. During this, "HO"/ "PLEASE WAIT" blinks on the display of the
remote controller. When the indoor unit to be controlled by the remote controller is missing,
"HO"/ "PLEASE WAIT" keeps blinking on the display of the remote controller even after 3 or more minutes
after power on.
*Note 2. The system may go into the error mode on either the indoor unit or the heat source unit side. The heat
source unit stops only when all of the connected indoor units are experiencing problems. The operation of
even a single indoor unit will keep the heat source unit running. The error will be indicated on the LED display.
*Note 3. The units will follow the operation mode commands from the BC controller
*Note 4. When the operation mode commands from the BC controllers are mixed (both cooling and heating), the
actual operation mode is determined by the heat source unit.
HWE15060
Start
Breaker
turned on
YES
*Note 1
Indoor units
registered to the
remote controller
NO
YES
2
NO
Operation
command
YES
fan
Operation
mode
*Note 2
Error mode
NO
72C ON
*Note 3
Operation
mode
Cooling Only Heating Only
Operation command to the BC controller
2
NO
Cooling only, Heating only
Mixture of units in cooling and heating
YES
Mixture of units in cooling and heating
*Note 4
Operation
mode
Cooling Main Heating Main
- 181 -
Normal operation
Error
Unit in the stopped state
Error stop
Error display on the
heat source unit LED
Self-holding of
protection function
Operation command
to the BC controller
GB