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Electric control
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Control of auxiliary electric heating
The start of electrical heating is to provide an auxiliary heating function at low temperatures. The inlet and outlet of
the auxiliary electric heating are connected in series to the total outlet pipe of the air-cooling module unit, and the
control node for auxiliary electric heating is provided in the electric control cabinet of the main module of the unit
(only 220V output control signal is provided, and the electric heating control part is provided by the user).
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Selection of auxiliary electric heater
According to the needs of the project, it is recommended to install an auxiliary electric heater as the backup
system. When the equipment is frosted or the equipment has temporary failure, it will be opened as a backup
system. The main consideration of the selection of the water temperature auxiliary electric heater for the unit
is: the winter outdoor minimum Average ambient temperature, the size of the capacity used for the backup
system. According to the local minimum winter ambient temperature and the unit's outlet water temperature, the
corresponding capability value Q1 can be found in the “performance correction curve”. Compared with the unit
nominal value Q, the unit capacity attenuation value Q2 can be obtained.
Q2=Q- Q1
Generally choose the auxiliary electric heater ability W
W=a* Q2=a*(Q- Q1).
Where a is the margin coefficient, the value range is 1.0~1.5, and the value of a in the northern region should be
larger, such as 1.5 in Hubei and north.
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Pump operation control
In order to ensure the normal operation of the unit, it is necessary to use the pump and unit linkage control. The
chilled water pump linkage control contact is provided in the unit control cabinet (only 220V output control signal
is provided, and the pump control part is provided by the user). When the unit is in the standby state, the water
pump does not start. When the standby state enters the working state, the water pump is started first, and when
the machine is switched from the working state to the standby state or when the machine is shut down, the water
pump is automatically stopped after the operation is completed.
The choice of pump should meet the requirements of the unit: the water flow and the nominal value of the
nameplate should not exceed ± 30%.
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End linkage control
Pass the passive normally open contact of the end controller (open when the end is not activated and closed when
the end is started) to the main module linkage contact (LINE, OV). When the unit is in the power-on state, when
at least one end is started, the unit starts automatically. When all the ends are closed, the unit delay automatically
turns off. If the unit does not use the end linkage control, LINE and OV should be shorted.
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Overload protection control
In the unit control cabinet, the pump overload protection control contact and the auxiliary electric heating overload
protection control contact are provided (only 220V output contr ol signal is provided, and the passive thermal
relay for overload protection is provided by the user). The normally closed contact of the passive thermal relay is
connected to the overload protection control contact. When the current is too large, the thermal relay protection is
disconnected, and the unit alarm stops. If the unit does not use overload protection control, the overload protection
control contact should be shorted.
Note:
air conditioning side pump overload control contact (OV-P1, N), hot water side pump overload control
contact (OV-P2, N), air conditioning side auxiliary electric heating overload control contact (OV-H1, N), hot water
side Auxiliary electric heating overload control contacts (OV-H2, N).
In the heating mode, since the unit will attenuate with the decrease of the ambient temperature, in the area
where the outdoor outdoor ambient temperature is at the end of the winter, the user is strongly required to add
an auxiliary electric heater on the hot water side, otherwise the user's use effect will be affected.
WARNING