WH-SXC09H3E5, WH-SXC12H6E5, WH-UX09HE5, WH-UX12HE5 - Panasonic Air Conditioner Service Manual (repair manual). Page 116

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  To enable the base pan heater function, control panel initial setting has to be manually adjusted by activating 

Base Pan Heater menu. 

  There are 2 optional start condition can be selected, Type A or Type B. 

 Control 

details: 

1  Type A: (Default Auto Mode) 

Start conditions: 
o 

When outdoor air temperature ≤ 3°C during heating and deice operation is ON. 

 
Control contents: 
o 

Base pan heater is ON during deice operation and continues ON for 10 minutes after deice operation 
ends. 

 
Cancel condition: 
o 

When outdoor temperature > 6°C after deice end or 

o 

When operation is not at heating mode or 

o 

Base pan heater ON timer count is completed. 

 

2  Type B: (ON Mode) 

Start conditions: 
o 

When outdoor air temperature is ≤ 5°C and operates in heating mode, base pan heater is ON. 

 
Cancel conditions: 
o 

When outdoor air temperature is > 7°C or 

o 

When operation is not at heating mode. 

Purpose: 

-  To allow only one heater between room and tank heater to turn ON at the same time due to both heater 

power supplies is sharing the same ELCB. Prohibit two heater sources to turn ON at the same time to avoid 
overcurrent. 

 
Start condition: 

-  Tank heater function select YES by remote controller 

 
Control contents: 

a)  When there is only one heater source (Room Heater or Tank Heater) request to turn ON, operate same as 

normal room heater and tank heater operation. 

b)  When both backup heater and booster heater request to turn ON at same time, will turn ON only ONE heater 

source. Under normal condition, tank heater has priority to turn ON except below condition. 

i. 

Backup Heater Priority to Turn ON when 
-  Request Backup heater turn ON at Hex Protection control during deice. 
-  Request Backup Heater turn ON at Hex Protection Control during low water temperature. 
-  Request Backup Heater turn ON at Anti-frost control. 
-  Heat pump error and Force Mode operate. 

c)  When switching from booster heater to backup heater OR backup heater to booster heater, need to delay 5 

seconds in between Turn OFF one heater source and Turn ON another heater source.