Operation manual
5
EWWD120~540MBYNN
Packaged water-cooled water chillers
4PW22685-1
Safety devices
The unit is equipped with three kinds of safety devices:
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. For this
reason the unit does not need to be manually put on again after
a circuit safety occurred.
3
Part safety devices
Part safety devices shut down the part they protect.
An overview of all safety devices is given below.
■
Overcurrent relay
The overcurrent relays (K*S) are located in the switchbox of the
unit and protect the compressor motors in case of overload,
phase failure or too low voltage. The relays are factory-set and
may not be adjusted. When activated, they must be reset
manually, followed by a reset of the controller.
■
Compressor thermal protectors
The compressor motors are equipped with thermal protectors
(Q*M). The protectors are activated when the compressor motor
temperature becomes too high.
When temperature returns to normal, the protectors reset
automatically, but the controller needs to be reset manually.
■
Flowswitch
The unit is protected by a flowswitch (S8L).
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
The unit is equipped with discharge thermal protectors (S*T).
The protectors are activated when the temperature of the
refrigerant leaving the compressor becomes too high. When the
temperature returns to normal the protector resets automatically
and the controller needs to be reset manually.
■
Freeze-up protection
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 circuit.
When the outlet water temperature returns to normal, the unit
can start up again.
When freeze-up protection occurs several times in a certain
period, the freeze-up alarm will be activated and the unit will be
shut down. The cause of freezing up should be investigated and
after outlet water temperature has risen enough, the alarm
indicator on the controller needs to be reset manually.
■
Low pressure safety
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
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.
■
High pressure switch
Each circuit is protected by two high pressure switches (S*PH)
which measure the condenser pressure (pressure at the outlet
of the compressor). They are installed in the compressor
housing of the circuit. When the pressure becomes too high, the
pressure switches are activated and the circuit stops.
The switches are factory-set and may not be adjusted. When
activated, they must be reset by means of a screwdriver. The
controller still needs to be reset.
■
Reverse phase protector
The reverse phase protectors (R*P) prevent the screw
compressors from running in the wrong direction. If the
compressors do not start, two phases of the power supply must
be inverted.
Internal wiring - Parts table
Refer to the internal wiring diagram supplied with the unit. The
abbreviations used are listed below:
A1,A2..........** ....... Current transfo circuit 1, circuit 2
A1P........................ PCB-controller
A2P,A3P................. PCB-EEV driver circuit 1, circuit 2
A11P...................... Expansion board controller
(only for EWWD360~540)
B1P,B4P................. Low pressure transmitter for circuit 1, circuit 2
B2P,B5P................. High pressure transmitter for circuit 1, circuit 2
B3P,B6P................. Low pressure transmitter EEV for circuit 1 (A2P),
circuit 2 (A3P)
C11,C21 ................ Capacitor for capacity control
(only for EWWD360~540)
E1HC,E2HC .......... Crankcase heater compressor circuit 1, circuit 2
F1R,F2R ................ Fuses for reverse phase protector circuit 1,
circuit 2
F1U~F3U ....# ........ Main fuses
F6B,F11B .............. Fuse for primary of TR1
F7B ........................ Fuse for secondary of TR1
F8B ........................ Fuse for EEV driver
F8U........................ Surge proof fuse for A1P
F9B ........................ Surge proof fuse for secondary of TR2
F10B,F14B ............ Autofuse for secondary of TR2
F10S,F11S ............ Circuit breakers with fuses for circuit 1, circuit 2
(only for EWWD360~540)
F11U~F13U ........... Main fuses (only for EWWD360~540)
F21U~F23U ........... Main fuses (only for EWWD360~540)
H1P.............*......... Indication lamp general operation
H2P.............*......... Indication lamp alarm
H3P.............*......... Indication lamp operation compressor 1
H4P.............*......... Indication lamp operation compressor 2
(only for EWWD360~540)
H4P,H5P .....*......... Changeable output (only for EWWD120~280)
H5P,H6P .....*......... Changeable output (only for EWWD360~540)
J1........................... Power supply
J2,J3,J6,J20 .......... Analog input
J4........................... Analog output
J5,J7,J8,J19 .......... Digital input
J11......................... RS485 connection
J12~J18,J21,J22 ... Digital output
K1A,K4A ................ Auxiliary relay for safeties circuit 1, circuit 2
K1M,K4M............... Linecontactor for circuit 1, circuit 2
K2A,K5A ................ Auxiliary relay compressor thermal protector
circuit 1, circuit 2
K2M,K5M............... Deltacontactor for circuit 1, circuit 2
K3A,K6A ................ Auxiliary relay for discharge thermal protector
circuit 1, circuit 2
K3M,K6M............... Starcontactor for circuit 1, circuit 2
K7A,K8A ................ Auxiliary relay for high pressure circuit 1, circuit 2
K17S,K18S ............ Overcurrent relay for circuit 1, circuit 2
L1,L2,L3................. Main supply terminals
M1C,M2C .............. Compressor motor circuit 1, circuit 2
