Heater Control - Daikin RXYQ5-48MAY1 Service Manual

Si39-407
(3) Thermostat OFF by discharge air temperature
<Cooling>
Target discharge air temp. Ts – Discharge air temp. T4
<Heating>
&
6.7.3 Low Outdoor Air Temperature Protection Control
Objective In cooling (or fan operation) or heating, if outdoor air is low in temperature, stop the fan forcibly.
Details [Cooling and fan operation]
Turn OFF the fan for a period of 60 minutes at a suction temperature of 5 °C or lower.
In order to monitor the outdoor air temperature, however, turn ON the fan for a period of one
minute and turn OFF the fan again at a temperature of 5 °C or lower after the said timer
completes the operative period.
Reset the 60-minute timer when the fan stops running.
[Heating]
Turn OFF the fan for a period of 60 minutes at a suction temperature of –5 °C or lower.
In order to monitor the outdoor air temperature, however, turn ON the fan for a period of one
minute and turn OFF the fan again at a temperature of –5 °C or lower after the said timer
completes the operative period.
Reset the 60-minute timer when the fan stops running.
* The thermostat will not turn ON in one minute due to the temperature while the fan stops.
6.8

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) is
Function
>5 degree continue for 5 minutes.
→Thermostat stops for 1 minute. →Thermostat ON
Discharge air temp. T4 – Target discharge air temp. Ts >5 degree 



EV opening is low limit
This control shall be disabled at test run both in cooling and heating. (The test run shall be
conducted first.)
conducted through the liquid
pipe temperature (R2T) of the
indoor unit.
→Thermostat stops for 1 minute. →Thermostat ON
ON
ON 43ºC
*47ºC on Model FXAQ, FXLQ or FXHQ
Outline of Control (Indoor Unit)
continue for 5

minutes

Set temperature
2ºC 2ºC
50ºC Liquid pipe temperature
OFF
OFF
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