Pump Down Operation [Service Mode: 01]; Flow Switch - Panasonic WH-MDC05F3E5 Service Manual

12.2.4 Water Pump Speed Feedback Error

Basically pump speed feedback is control by micon.

When pump speed is below low limit or over high limit for a few seconds, micon detect pump error and
system is stopped.

Error detection conditions:
 Current pump speed < 1000 rpm or
 Current pump speed > 6000rpm for 10 seconds.

Control contents:
 When error occurs, water pump, heating and heater is stopped for 30 seconds then restart again (Retry
control).
 When micon detect error again, system is stopped and error code [H20] is displayed at control panel.
12.2.5 Water Pump Only Operation
Purpose
Circulate and fill the piping with water during installation time

Water pump only circulation can be set from the control panel SERVICE S/W when the operation is in
Standby Mode.

Press the SERVICE S/W for continuous 5 sec to enter Service Mode.

In Service Mode, select SR: 02 and press SET S/W to start water pump only operation.

3 way valve turn OFF and 2 way valve turn ON.

Water pump will stop operation when H62 is triggered.

Press the OFF/ON button to stop the water pump only operation.
12.3

Pump Down Operation [Service Mode: 01]

Purpose
Ensure the pump down operation when relocating or disposing of the unit. The pump down operation will extract all
refrigerant from the piping into the outdoor unit.
Controls:
1 Press the SERVICE S/W for continuous 5 seconds to enter Service Mode.
2 In service mode, select Sr: 01 and press SET S/W to start Pump Down operation.
3 There will be no low pressure error and freeze prevention judgement during Pump Down operation.
4 3 ways valve will shift to room side and 2 ways valve will turn ON.
5 Press OFF/ON button to stop the unit.
12.4

Flow Switch

12.4.1 Flow Switch Control
1 The water flow switch serves as an overload protector that shuts down the unit when the water level is
detected to be low.
2 Detection is Lo (0 V) when there is no water flow, and detection is Hi (5 V) when there is water flow.
62