Freeze Prevention Control; Hot Start Control (In Heating Operation Only) - Daikin RMXS-L Series Service Manual

SiUS181305E
8.3

Freeze Prevention Control

When the temperature detected by liquid pipe thermistor (R2T) of the indoor heat exchanger drops
too low, the unit enters freeze prevention control in accordance with the following conditions, and is
also set in accordance with the conditions given below.
Conditions for starting: Temperature is –1°C (30.2°F) or less for total of 40 min., or temperature is
–5°C (23°F) or less for total of 10 min.
Conditions for cancelling: Temperature is +7°C (44.6°F) or more for 10 min. continuously
Ex: Case where temperature is –5°C (23°F) or less for total of 10 min.
8.4

Hot Start Control (In Heating Operation Only)

Outline
At startup with thermostat ON or after the completion of defrosting in heating operation, the indoor
unit fan is controlled to prevent cold air from blasting out and ensure startup capacity.
Detail
Function
+ 7˚C
(44.6˚F)
+ 0˚C
(32˚F)
– 5˚C
(23˚F)
10 min.
Defrost ending or oil return ending
or Thermostat ON
Hot start control
H/L remote
controller setting
LL
OFF
Remote controller
setting
Level position
Freeze prevention control
Forced OFF by thermostat
Hot start in progress
The fan is not OFF before initiating the hot start: LL
The fan is OFF before initiating the hot start: OFF
TH : Temperature detected by the gas thermistor
2
Tc: High pressure equivalent saturation temperature
Function of FFQ Series
10 min.
Normal operation
(R18813)
Hot start ending conditions
·
lapse of 3 minutes
·
OR
TH > 34˚C (93.2˚F)
2
·
Tc > 52˚C (125.6˚F)
Normal operation
Normal operation
(R19187)
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