Daikin EWYQ130DAYN [384/524] Anti freeze function or inlet outlet water temperature

Functional Control for a Standalone Unit ESIE06-05

2–158 Part 2 – Functional Description

3.18.1 Anti-Freeze function or inlet/outlet water temperature

Freeze-up

prevention

Freeze-up prevention will request a load-down when the temperature of the evaporator outlet water

gets below the freeze-up disable setpoint +0.5 °C. If 1 compressor is reduced immediately, reset the

load up/down timers (and start recounting). After reducing 1 compressor in operation, when the

temperature is still in this area, reduce 1 more compressor after 15 seconds. Repeat this until only 1

compressor remains in operation. If only 1 compressor remains on, do not execute this procedure.

Freeze-up

protection for

software version

2.1

When the evaporator outlet water temperature sinks below Freeze-up disable setpoint freeze-up

protection is activated and the unit is shut down. When the temperature rises above the reset setpoint,

protection is reset and the unit will work in its initial mode after compressor timers. The compressor

will go back to the necessary capacity step, depending on the load-up possible status.

Important : No alarm is displayed after freeze-up protection. Unit will restart after the REF GRD

EXTEND timer (12 min).

Characteristics Freeze-up prevention

Control device Sensor

Diagram name R3T, R4T

Activation

Result

When 2 or more compressors are in operation

AND

If leaving water temperature < FREEZE UP DIS +

0.5 °C.

Load down compressor every 15 seconds until 1

compressor is in operation.

Reset

Result

If leaving water temperature > RESET value

Normal mode.

Characteristics Freeze-up prevention

Control device Sensor

Diagram name R3T, R4T

Activation

Result

Leaving water temperature < FREEZE UP DIS

Unit disabled

Reset Reset when leaving water temperature rises

above MOW setpoint.