Installation, Start-Up, Adjustment and Maintenance Manual
56
6.3 CHILLED WATER TEMPERATURE REGULATION
When DDC is used, the following menu3 set-up is not to be done. It’s necessary to consult “Installation and Programming
manual of DDC - Direct Digital Controller”.
If the unit isn’t connected to a DDC, chilled water temperature regulation can be set up from menu 3 of the
S61 card (see APPENDIX: S61 electronic card).
MENU 3 – End User Adjustment
MENU
SIGNALS
DESCRIPTION OF MENU SIGNALS
Thermostat action
Cold water set point
Cold water temperature difference
∆
T
Exit
Table 22
– MENU 3 PARAMETERS
The
thermostat action
parameter can assume 2 values: 0 and 1. When 0 is set, temperature to drive the
unit is read by the INLET probe; when 1 is set, the temperature is read by the OUTLET probe.
The
set-point
is intended to be the pre adjusted water temperature (in/out), when being achieved, the unit
will start the switching off cycle as (since) the conditioning request is met. This parameter can assume
values from a factory set minimum value up to 77°F.
The
temperature difference
is intended to be a value, which should be summed up by the pre adjusted set
point temperatures. This parameter can assume values from 1.8°F up to 14.4°F.
The obtained value represents the water temperature. According to this temperature, the conditioning
request will be re activated and then the unit will start–up again .
For example, let us suppose the following adjustments :
-
Thermostat action: unit operation with outlet temperature
-
set-point
+44°F;
-
Temp. difference
2 ;
The unit behaves as follows :
-
One time during the unit operation, the water of HYDRONIC system is getting cold until the outlet water
temperature reaches
+44°F
(set-point temperature);
-
Up on achieving that temperature, the unit will be switched off automatically.
-
When the water temperature starts getting high, reaches
+46°F
(that is
+44°F
plus the temp difference
of
2
) the unit will start-up again to cool the water once more until reaching
+44°F
, and so on.
Then, according to these adjustments the unit switches off at
+44°F
and starts-up at
+46°F.
To set up the parameters use the encoder knob:
- To select a menu, a parameter or a value rotate the knob.
- To enter a value press the knob
(see APPENDIX: Electronic system of the ACF60-00 unit).