Daikin EUWA/Y5-30HB/C(Z) - Defrost Principle (Only for EUWY5-30 HB;C(Z))

ESIE98–06A Functional Control
Part 2 – Functional Description 2–7
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2
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1.4 Defrost Principle (only for EUWY5-30HB/C(Z))
Introduction This chapter explains the principle of defrost. In the next chapter (refer to 1.5 – Defrost Circuit Control)
we concentrate on the location of the defrost PCB in the switch box and on the wiring diagram and we
will give an overview of the different defrost circuit combinations.
Defrost control
overview
The defrost start condition needs to be activated for 2.5 minutes (150 seconds) before the actual
defrost starts. The minimum time interval between two defrost cycli is 20 minutes.
Start condition
detail for
EUWY15-30HC
The relation between the coil sensor temperature and the ambient temperature for chiller types
EUWY15-30HC is illustrated in the figure below:
Unit Start condition Display Stop condition Display
5-10HB T
coil
< -10 °C d1 ■ T
coil
> +10 °C ■ normal display
■ after 10 min ■ the display flashes, alternately
showing r1 and the inlet water
temperature
15-30HC T
coil
< 0.6 x T
amb
- 10
(±3)
Range ±3 adjustable
with variable resistor.
DEFROST BUSY ■ T
coil
> +10 °C ■ normal display
■ after 10 min ■ normal display
-5 +5 +10 0
-10
-7
-13
T
coil
(°c)
coil sensor temperature
T
amb
(°c)
ambient temperature
adjustable with variable resistor on the print
range: ± 3°C
T
coil
< 0,6 • T
amb
- 10 (±3)
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