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AB Industrietechnik srl – Via Julius Durst, 70 – 39042 BRESSANONE (BZ) Italy – Tel: +39 0472/830626 – [email protected] – www.industrietechnik.it
During operation, the ON or OFF icons indicates the status of the heat exchanger:
Icon status
Indication
ON icon is on
pump activated, heat recovery in progress
OFF icon is flashing
Pump closed for free heating or free cooling
OFF icon is on
Pump closed, heat exchanger off
By Modbus, it is also possible to see the status of the heat exchanger (see
“41. Modbus (for AHU-xMxSx1 models)” page 137
).
Note: Frost protection of heat exchanger is not considered on double battery heat exchanger as there is never frost on bat
-
teries. If a frost protection heat exchanger alarm occurs, a message of alarm appears on alarm pages only.
• Rotary on/off heat exchanger:
To be able to operate, ventilation must be activated; otherwise, it is always disabled.
if a request of cooling/heating is present with cooling recovery/heating recovery conditions, the rotary on/off heat exchanger
is activated.
If a on/off bypass damper is present, it operates opposite to heat exchanger.
If a modulating bypass damper is present, the modulating damper modulates the recovery based on cooling/heating request.
Operation with modulating bypass heat exchanger and modulating cooling valve:
Do following settings:
- set type of heat exchanger
012
=3
,
- select a digital output for the rotary on/off heat exchanger
025
=14 (DO1) or
026
=14 (DO2) or
027
=14 (DO3) or
028
=14 (DO4)
or
029
=14 (DO5)
- do the regulation on room sensor (internal or remote sensor)
001
=0;
- define the return air sensor
019
=1 (AI1) or
021
=1 (AI2) or
023
=1 (AI3)
-
define external sensor
019
=3 (AI1) or
021
=3 (AI2) or
023
=3 (AI3).
If return sensor or external sensor is broken (open or short-circuit), heat exchanger is deactivated.
- Modulating bypass damper for heat exchanger
010
=4,
011
=1,
030
=13 (AO1) or
031
=13 (AO2) or
032
=13 (AO3).
- modulating cooling valve
003
=1 and
030
=4 (AO1) or
031
=4 (AO2) or
032
=4 (AO3)
or modulating mixed-use cooling valve
002
=2
003
=1 and
030
=5 (AO1) or
031
=5 (AO2) or
032
=5 (AO3).
100%
0%
Treg
114
WHS
114
/2
100%
0%
Treg
116
WCS
116
/2
Treg
178
100%
0%
100%
0%
Treg
WCS
178
Treg
178
100%
0%
100%
0%
Treg
116
WCS
116
/2
178
Treg
178
100%
0%
P
Bypass
100%
0%
Treg
WCS
178
Treg
178
100%
0%
Bypass
P
Treg
178
100%
0%
100%
0%
Treg
WHS
Treg
178
100%
0%
178
100%
0%
Treg
114
WHS
114
/2
178
100%
0%
Treg
178
Bypass
100%
0%
Treg
WHS
178
100%
0%
Treg
178
Bypass
P
P
Bypass
Bypass
P
P
Treg: control temperature
WCS: cooling operation setpoint
116
: cooling proportional band
178
:
hysteresis regulation free heating/cooling
solid curve upper part: modulating bypass damper output
dashed curve: modulating cooling valve output
P: rotary on/off heat exchanger output
With cooling recovery conditions:
If temperature of regulation sensor rises above WCS, icon
is switched on, the rotary on/off heat exchanger is activated
and the modulating bypass damper goes from the maximum opening position (parameter
165
) to the minimum opening posi
-
tion (parameter
164
) in the band defined by
116
/2. The cooling valve goes from closed position to open position when Treg
changes from (WCS +
116
/2) to (WCS +
116
).
The rotary on/off heat exchanger is deactivated if Treg <= (WCS -
178
). The icon is switched off.
