Panasonic WH-MDC05J3E5, Service Manual, Page: 131 / 246

131
14.20 Boiler Bivalent Control

Boiler is an additional or alternative heat source to heat up the room when necessary.

Purpose of this control is to turn ON and turn OFF the Boiler output signal when boiler heating capacity needed in
the system.

Boiler is possible to connect to DHW Tank and Buffer Tank depends on the installer.

Boiler operation parameter need to be set on Boiler itself, indoor do not control the boiler operation direction and
operation.

There is two option of control pattern can be set by remote controller : AUTO OR SG ready Mode
AUTO Control Mode:

There are Alternative mode, Parallel mode, & Advance Parallel mode available to select by installer to fit to the
total system.
Bivalent control selection by remote controller
Remote control setting value:
1 Outdoor Ambient Set = (Range: -15°C ~ 35°C)

Alternative Mode
o
Only one heat source operates at one time, either heat pump or boiler depends on condition.
o
External pump will turn ON when the external pump selection is ON when boiler is ON even heat pump is
OFF.
Control detail:
During Operation ON at Heat mode or Tank mode or Heat + Tank Mode
o
Boiler signal turn ON and heat pump and water pump turn OFF when:
 Outdoor ambient < Outdoor Ambient Set AND

Boiler prohibit flag = 0
** However indoor water pump can operate when Anti-freeze control condition fulfilled.
o
Boiler signal turn OFF and heat pump and water pump turn ON when:
 Outdoor ambient > Outdoor Ambient Set + [2°C] OR
 Boiler prohibit flag = 1

Parallel Mode
o
Parallel mode allows heat pump and boiler ON at the same time. Boiler operates as an additional heating
capacity when low heat pump capacity at low ambient condition.
Control detail:
During operation ON at Heat mode or Tank mode or Heat + Tank mode
o
Boiler signal turns ON when:
 Outdoor ambient < Outdoor Ambient Set AND

Boiler prohibit flag = 0
o
Boiler signal turns OFF when:
 Outdoor ambient > Outdoor Ambient Set + [2°C] OR
 Boiler prohibit flag = 1

Advance Parallel Mode
o
Advance parallel mode allow heat pump to operate and turn ON boiler only when ambient and temperature
condition is fulfilled.
Remote control setting value:
1 Outdoor Ambient Set = (Range : -15°C ~ 35°C)
2 Selection of boiler connection direction. (Heat only, DHW only, Heat & DHW)
3 Setting data under Heat Direction
o
Start Temperature | START_TEMP |
o
Start Delay Timer | START_TIMER |
o
Stop Temperature | STOP_TEMP |
o
Stop Delay Timer | STOP_TIMER |
4 Setting data under DHW Direction
o
Delay Timer | DELAY_TIMER |