Freeze Prevention; Heater Control - Daikin CMSQ200A7W1B Service Manual

Outline of Control (Indoor Unit)
6.8

Freeze Prevention

Freeze When the temperature detected by liquid pipe temperature thermistor (R2T) of the indoor unit
heat exchanger drops too low, the unit enters freeze prevention operation in accordance with
Prevention by Off
the following conditions, and is also set in accordance with the conditions given below.
Cycle (Indoor
Unit)
Conditions for starting freeze prevention: Temperature is -1°C or less for total of 40 min., or
temperature is -5°C or less for total of 10 min.
Conditions for stopping freeze prevention: Temperature is +7°C or more for 10 min.
continuously
Ex: Case where temperature is -5°C or less for total of 10 min.
6.9

Heater Control

The heater control is conducted in the following manner.
[Normal control]
While in heating operation, the 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) The heater control (ON/OFF)
60
is conducted through the
liquid pipe temperature (R2T)
of the indoor unit.
ON
ON 43ºC
SiBE28-805
Set temperature
2ºC 2ºC
50ºC Liquid pipe temperature
OFF
Function
OFF