Daikin EWYQ080DAYN, Operation Manual

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Operation manual
5
EWYQ080~250DAYN
Packaged air-cooled water chillers
4PW35558-1B
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4-way valve
The 4-way valve reverses the refrigerant flow in the unit to
change from cooling mode to heating mode.
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Evaporator
The main function of the evaporator is to take heat from the
water that flows through it. This is done by turning the liquid
refrigerant, coming from the condenser, into gaseous
refrigerant.
■
Non-return valve
The non-return valve prevents the refrigerant from flowing in the
wrong direction.
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Water in/outlet connection
The water inlet and outlet connection allow an easy connection
of the unit to the water circuit of the air handling unit or industrial
equipment.
Safety devices
The unit is equipped with three kinds of safety device:
1 General safety devices
General safety devices shut down all circuits and stop the whole
unit. For this reason the unit has to be manually put on again
after a general safety occurred.
2 Circuit safety devices
Circuit safety devices shut down the circuit they protect, while
the other circuits remain activated.
3 Part safety devices
Part safety devices shut down the part they protect.
An overview of all safety devices is given below.
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Overcurrent relays
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Overcurrent relay for compressors (only for SJ161-4) (circuit
safety device)
The overcurrent relay protects the compressor motor in case of
overload, phase failure or too low voltage.
■
Overcurrent relay for fans (part safety device)
The overcurrent relay protects the fan motors in case of overload,
phase failure or too low voltage.
■
Overcurrent relay for pump (general safety device)
The overcurrent relay protects the pump in case of overload,
phase failure or too low voltage.
When activated, the overcurrent relays have to be reset in the
switch box and the controller needs to be reset manually.
■
Compressor SJ161-4 thermal protector (part safety devices)
Compressor SJ161-4 is equipped with an internal overload
motor protection to protect the unit against excessive current
and temperature caused by overloading, low refrigerant flow or
phase loss. The compressor will shut down and will
automatically restart when temperature returns to normal. This
is not detected by the controller.
■
Compressor SJ180-4 electronic protection module (circuit safety
device)
Compressor SJ180-4 is equipped with an electronic protection
module to provide for efficient and reliable protection against
overheating, overloading, and phase loss. The controller will
detect the shut down of the compressor. The controller needs to
be reset manually. The compressor is internally protected
against reverse phase.
■
Compressors SJ240-4 and SJ300-4 electronic protection
modules (circuit safety device)
Compressors SJ240-4 and SJ300-4 are equipped with an
electronic protection module to provide for efficient and reliable
protection against overheating, overloading, phase loss and
phase reversal. The controller will detect the shut down of the
compressor. The controller needs to be reset manually.
■
Reverse phase protector (general safety device)
The reverse phase protectors prevent the unit from being
operated in reverse phase. If the unit does not start, two phases
of the power supply must be inverted.
■
Flowswitch (general safety devices)
The unit is protected by a flowswitch (S1L).
When the water flow becomes lower than the minimum allowed
water flow, the flowswitch shuts down the unit. When the water
flow becomes normal, the protection resets automatically but the
controller still needs to be reset manually.
■
Discharge thermal protectors (circuit safety devices)
The unit is equipped with discharge thermal protectors (R*T).
The protectors are activated when the temperature of the
refrigerant leaving the compressor becomes too high. When the
temperature returns to normal the controller needs to be reset
manually.
■
Freeze-up protection (general safety devices)
The freeze-up protection prevents the water in the evaporator
from freezing during operation.
■
When the outlet water temperature is too low, the controller
shuts down the compressors. When the outlet water
temperature returns to normal, the controller resets
automatically.
■
When the refrigerant temperature is too low, the controller
shuts down the unit. When the refrigerant temperature
returns to normal, the controller needs to be reset manually.
■
Low pressure safety (circuit safety devices)
When the suction pressure of a circuit is too low, the circuit
controller shuts down the circuit. When the pressure returns to
normal, the safety device can be reset on the controller.
■
Pressure relief safety valve (general safety devices)
The safety valve is activated when the pressure in the refrigerant
circuit becomes too high. If this occurs, shut down the unit and
contact your local dealer.
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High pressure setback (circuit safety device)
The high pressure setback prevents the high pressure to
become too high so that high pressure switch is activated.
When the high pressure is too high, the controller shuts down
the compressor. When the pressure returns to normal, the
controller resets automatically.
■
High pressure switch (circuit safety devices)
Each circuit is protected by a high pressure switch (S*PH) which
measures the condenser pressure (pressure at the outlet of the
compressor).
When the pressure becomes too high, the pressure switch is
activated and the circuit stops.
When the pressure becomes normal again, the protection resets
automatically but the controller still needs to be reset manually.
The switch is factory-set and may not be adjusted.
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Compressor protection function
The compressor protection function protects the compressor,
while running in heating mode, from operating outside operation
range.
If low pressure and high pressure temperatures are outside
operation range, the controller shuts down the compressor.
When the low pressure and high pressure temperatures return
to normal, the controller resets automatically.
The overcurrent relays are factory set and may not be
adjusted.