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AB Industrietechnik srl – Via Julius Durst, 70 – 39042 BRESSANONE (BZ) Italy – Tel: +39 0472/830626 – [email protected] – www.industrietechnik.it
21. Regulation with free cooling, free heating
•
Operation with on/off bypass damper for cross-flow heat exchanger
if the damper used is bypass for heat exchanger (based only on free heating/cooling,
010
=5), the damper is regulated directly
with free cooling and/or heating conditions defined in the previous paragraph, regardless request of cooling and/or heating.
The following settings must be done:
-
170
=1 or 3 (authorization of free cooling regardless the working season), or
170
=4 or 6 (authorization of free cooling in cool
-
ing mode only), or
170
=2 or 3 (authorization of free heating regardless the working season), or
170
=5 or 6 (authorization of
free heating in heating mode only),
- do the regulation on room sensor (internal or remote sensor)
001
=0;
in case the remote sensor is used set an analogue input as remote sensor
019
=1 (AI1) or
021
=1 (AI2) or
023
=1 (AI3)),
- set an analogue input as external sensor
019
=3 (AI1) or
021
=3 (AI2) or
023
=3 (AI3),
- set a digital output as on/off bypass for heat exchanger (based only on free c/h):
025
=20 (DO1) or
026
=20 (DO2) or
027
=20
(DO3) or
028
=20 (DO4) or
029
=20 (DO5), action on damper
011
=1,
- set the type of heat exchanger to cross-flow heat exchanger
012
=1.
Free cooling:
Free heating
Treg - Text
ON
OFF
Text - Treg
Bypass
172
171
ON
OFF
Bypass
172
171
Treg - Text
ON
OFF
Text - Treg
Free heating
conditions
172
171
ON
OFF
Free cooling
conditions
172
171
Treg: room control or return temperature
Text: external temperature
171
: differential setpoint for free cooling/heating
172
: proportional band for free cooling/heating
Using the free cooling conditions:
Text >=
174
Treg >=
175
(Treg - Text) <
173
If (Treg - Text) >
171
-> the bypass damper is activated (open).
If (Treg - Text) <=
172
the bypass damper is disabled (closed).
Using the free heating conditions:
Text <=
176
Treg <=
177
(Text - Treg) <
173
If (Text - Treg) >
171
the bypass damper is activated (open).
If (Text - Treg) <=
172
the bypass damper is disabled (closed).
