Daikin EWWQ-AJYNN Service Manual page 59

ESIE07-05
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Other settings
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EXAMPLE: Upload
1)
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2)
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3)
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4a)
4b)
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Part 2 – Functional Description
Start up ∆T : 2.7°C
Shutdown ∆T : 1.7°C
Regulation band : 3°C
If the water temperature is above 9.7°C the chiller can start (below 9.7°C the chiller will wait)
Unit will start leader compressor
Unit will load leader compressor till 75%
If temperature is in Regulation Band
wait interstage time (default 210 sec)
If temperature is approaching setpoint (after interstage time)
wait (no need to start new compressors because chilled water temperature is decreasing,
prevent undershoot)
After interstage time check if temperature is in unloading band
No: Unit will add next compressor (25% capacity) and keep the leader compressor at 75%
Leader comp : 75%
Next comp : 25%
Yes: Unit will first unload leader compressor to 50%, when this is done the next compressor
will start (25%)
Leader comp : 50%
Next comp : 25%
This will give you again 75% capacity but now the unit is able to upload in small steps.
Unit will upload the running compressors to 75%
■ If another compressor is present and there is still demand for load, the regulation cycle will
continue from point 3.
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If no other compressors are present and there is still demand for load, the compressors will
upload to 100% capacity according to the PID regulation (if needed).
When the temperature is in the dead band, the unit will operate with the same capacity (no upload
or download)
Functional Control
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