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12.6 Indoor Back-Up Heater Control
12.6.1 Indoor Electric Heater Control
1 Normal Heating Mode
o
Heater
On
condition:
a. Heater switch is ON
b. After Heatpump thermo ON for
[30]
mins
c. After water pump operate
[9]
mins
d. Outdoor air temperature < Outdoor set temperature for heater
e. When water outlet temperature < Water set tempe
[-4
°
C]
f.
[20]
minutes since previous Backup heater Off
* When heatpump cannot operate due to error happens during normal operation, heater will go into
force mode automatic
* Heater need to operate during deice operation
o
Heater Stop Condition:
a. When outdoor set temperature > outdoor set tempe
[+2
°
C]
for continuous 15 secs OR
b. When water out temp> water set tempe
[-2
°
C]
for continuous 15 secs OR
c. Heater switch is Off OR
d. Heatpump thermo-off or OFF condition
2 Force
Heater
Mode
o
Heater
On
condition:
a. After water pump operate
[9]
mins
b. When water outlet temperature < water set tempe
[-4
°
C]
c.
[20]
minutes since previous Backup heater Off
o
Heater Stop condition
a. Force mode off
OR
b. When water outlet temperature > water set tempe
[-2
°
C]
for continuous 15 secs
* Do not operate heater at the following situation
1 Water outlet temperature sensor, and water inlet sensor abnormal
2 Flow switch abnormal
3 Circulation pump stop condition