Heater Control (Except Ftq-Ta Models) - Daikin SkyAir RZR-TA Series Service Manual

Outline of Control (Indoor Unit)
6.9

Heater Control (Except FTQ-TA Models)

Note(s)
Optional PCB KRP1B... is required for heater control.
Heater control is conducted in the following manner.
Normal control
While in heating operation, heater control (ON/OFF) is conducted as shown on the right.
Overload control
When the system is overloaded in heating operation, the heater will be turned OFF in the following
two manners.
(1) Heater control (ON/OFF) is conducted through the liquid pipe temperature (R2T) of the indoor
unit.
(2) Heater control (ON/OFF) is conducted by converting the heater temperature into the
condensing pressure equivalent saturated temperature (Tc) according to the temperature detection
through the high pressure sensor (S1NPH) of the outdoor unit.
Fan residual operation
When the heater turns OFF, in order to prevent the activation of the thermal protector, the fan
conducts residual operation for a given period of time after the heater turns OFF. (This operation is
conducted regardless of whether or not a heater is equipped.)
Residual operation time: 100 seconds on ceiling suspended type or 60 seconds on other types
136
O N
2ºC
(3.6˚F)
43ºC
ON
(109.4˚F)
50ºC
(122˚F)
ON
S t e e t m p e a r u t e r
OFF
2ºC
(3.6˚F)
50ºC
(122˚F) Liquid pipe temperature
OFF
60ºC
(140˚F) Condensing pressure
equivalent saturated
temperature
OFF
SiUS281811EA
Part 4 Functions and Control