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Access 4.x |
Plate exchanger defrosting with temperature monitoring |
Exhaust air (alternatively Defrosting) temperature is constantly measured.
The defrosting controller (PID) will take over control of sequence output (exchanger bypass) if temperature falls below [-3] oC.
The flow of cold Outdoor - Supply air is gradually diverted from the exchanger to bypass while the flow of warm Extract - Exhaust air remains unchanged.
The intended imbalance of the air flows through the exchanger reduces transfer of thermal energy and as a result has a defrosting effect.
Configuration of defrosting with temperature monitoring |
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Variable |
Available options & Selection |
Note |
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Sequence selection |
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Configuration > Functions > Function activation > Heating/Cooling sequence setup |
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Sequence for exchanger |
...| SEQ-B Exchanger |... |
Select sequence for exchanger |
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Sequence settings |
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Configuration > Functions > Function activation > Heating/Cooling sequence setup > Exchanger |
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Type of sequence |
...| Exchanger |... |
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Type of exchanger |
| Rotary | Plate | Liquid | |
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Type of defrosting |
...| Temperature monitoring |... |
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Defrosting configuration |
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Configuration > Functions > Temperature control > Defrosting temperature monitoring |
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Temperature sensor |
| Exhaust air | Defrosting | |
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Extract air fan speed when fan stop defrosting |
|Auto | Low | Normal | High | |
Operation level of the extract air fan when the supply air fan is stopped |
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Allocate analog input |
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Configuration > I/O allocation settings > Analog inputs |
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Exhaust air temperature |
Any available I/O |
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PID Settings |
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Configuration > PID controllers > Defrosting |
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P-band |
[16] oC |
PID settings for the defrosting controller |
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I-time |
[240] s |
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D-time |
[0] s |
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Defrost operational settings |
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Data & Settings > Temperature control > Exchanger > Defrosting temperature monitoring |
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Setpoint min limit |
[-3] oC |
Defrosting starts when the exhaust (defrosting) temperature is < -3 oC and will continue until it becomes +1 oC (-3 oC + 4 oC), but not less than 15 minutes |
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Hysteresis to end defrosting |
[4] oC |
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Min time |
[15] min |
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Stop supply air fan if outdoor temp < |
[-100] oC |
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