Operation manual
25
EWAQ080~260DAYN
Packaged air-cooled water chillers
4PW35556-1E
A
NNEX
I
Thermostat parameters
Water temperature control
The figures below show the thermostat diagram in case of inlet water temperature control.
■
Stand alone thermostat
(1)
(inlet or outlet)
The default value and the upper and lower limits of the
thermostat parameters are listed in the table below.
■
DICN thermostat
(1)
(inlet)
The default value and the upper and lower limits of the
thermostat parameters are listed in the table below.
■
If the temperature is below the setpoint, the thermostat control
will check every LOADDOWN TIMER.
According to the deviation to the setpoint, no action, load up,
down is required.
■
If the temperature is above the setpoint, the thermostat control
will check every LOADUP TIMER.
According to the deviation to the setpoint, no action, load up,
down is required.
(1) Loadup request of 1 compressor: request to add one additional compressor.
Loadup request of 2 compressors: request to add 2 additional compressors (with interval of 15 seconds inbetween).
The maximum number of compressors that can possibly be added in 1 request is limited to the total number of units that are present in the DICN setup:
Example: A DICN setup with 2 units means load up requests of maximum 2 compressors at a time.
INLET CONTROL
Default value
Lower
limit
Upper
limit
Units 1
circuit
Units 2
circuits
Step difference - a
(K)
4.0
(*)
(*)
can only be modified in the service menu
2.0
(*)
—
—
Steplength - c
(K)
0.2
(*)
—
—
Loadup timer
(sec)
180
15
300
Loaddown timer
(sec)
30
15
300
Setpoint
(°C)
12.0
7.0
23.0
OUTLET CONTROL
Default value
Lower
limit
Upper limit
Units 1
circuit
Units 2
circuits
Step difference - a
(K)
4.0
(*)
(*)
can only be modified in the service menu
2.0
(*)
—
—
Steplength - c
(K)
0.2
(*)
—
—
Loadup timer
(sec)
30
15
300
Loaddown timer
(sec)
15
15
300
Setpoint
(°C)
7.0
4.0
20.0
c
c
a/2
a/2 a/2
a/2
c
c
a/2 a/2
c
c
a/2
a/2 a/2
a/2
c
c
a/2 a/2
Inlet setpoint
Load up request of 1 compressor
no action
Load down request of 1 compressor
Outlet setpoint
INLET CONTROL
Default value
Lower limit
Upper limit
Step difference - a
(K)
4.0
(*)
(*)
can only be modified in the service menu
—
—
Step difference - b
(K)
3.6
(*)
—
—
Step difference - c
(K)
0.4
(*)
—
—
Loadup timer
(sec)
180
15
300
Loaddown timer
(sec)
180
15
300
Setpoint
(°C)
12.0
7.0
23.0
c
c
c
c
b
b
a/2
a/2 a/2
a/2
c
c
c
c
b
b
a/2 a/2
Inlet setpoint
Load up request of 4 compressors
Load up request of 3 compressors
Load up request of 2 compressors
Load up request of 1 compressor
no action
Load down request of 1 compressor
Load down request of 2 compressors
Load down request of 3 compressors
Load down request of 4 compressors