EWWQ090G ÷ EWWQ720L - R410a - Water-cooled scroll chillers
EWLQ090G ÷ EWLQ720L - R410a - Condenser less
EWHQ100G ÷ EWHQ400G - R410a - Heat pump scroll chillers
Water cooled scroll chillers & heat pump
Operation
Manual
Operation Manual
34
EWWQ - EWLQ - EWHQ
Water colled scroll chiller &heat pump
D-EOMWC01203-15EN
are activated according to Operating mode and Dual Setpoint selection. All default setpoint with
their ranges are reported in the table below.
Actual Operating Mode
Double Setpoint Input
LWT Setpoint
Default
Range
Cool
OFF
Cool LWT 1
7.0°C
4.0°C
15.0°C
ON
Cool LWT 2
7.0°C
4.0°C
15.0°C
Cool w/ Glycol
OFF
Cool LWT 1
7.0°C
-10.0°C
15.0°C
ON
Cool LWT 2
7.0°C
-10.0°C
15.0°C
Ice
N/A
Ice LWT
-4.0°C
-10.0°C
4.0°C
Heat
OFF
Heat LWT 1
45.0°C
25.0°C
55.0°C
ON
Heat LWT 2
45.0°C
25.0°C
55.0°C
The LWT setpoint can be overridden in case the setpoint reset (for details see chapter 5.1.7.2).
Dual Setpoint, Setpoint Reset are not operational in Ice Mode.
5.1.4 Thermostat Control Settings
Thermostat control settings allow to set up the response to temperature variations and the
precision of the thermostat control. Default settings are valid for most applications, however site
specific conditions may require adjustments in order to have a smooth and precise temperature
control or a quicker response of the unit. The parameters mentioned below can be set from the
menu 4.2.1
The following explanation can be read for Chiller/Heat Pump modes.
Compressors start conditions.
The control will start the first compressor if the controlled
temperature is higher/lower than the active setpoint of at least a
Start Up DT
value. The other
compressors will start, one at a time, if the controlled temperature is higher/lower than the active
setpoint of at least
Stage Up DT
value.
Compressors shutdown conditions.
The control will shut down the compressors, one at a time,
if the controlled temperature is lower/higher than the active setpoint of at least
Stage Down DT
value. Last compressor in run will shut down if the controlled water temperature is lower/higher
than the active setpoint of at least
Shut down DT
value.
Temperature Limitation.
The start-up and shut-down of all compressors are inhibited if the
controlled water temperature decreases/increases faster than
Pull Down Rate/Pull Up Rate
limit
value.
Time Limitation.
The start-up and shut-down of each compressor must respect the following time
constrains.
1. A compressor can start only if since the last start-up or shut-down of any other compressor
the
Stage Up Delay
has expired.
2. A compressor can stop only if since the last start-up or shut-down of any other compressor
the
Stage Dn Delay
has expired.
3. A compressor can start only if since its previous start-up the
Start to Start Delay
has
expired
4. A compressor can start only if since its previous stop the
Stop to Start Delay
has expired
The unit capacity remains constant if the controlled temperature is within the interval: