Fujitsu WATERSTAGE WOYG160LJL Maintenance Document page 77

Mixing Valve Control
Line Nr Programming line
938 Mixing valve cooling off set
941 Actuator running time
945 Mixing valve in heating mode
Mixing valve cooling off set
The cooling demand issued by cooling circuit 1 to
production is reduced by the adjusted value.
If there is a second zone, this reduction should enable
the second zone to be cooled. To achieve this result,
the sub-cooling must be determined in accordance with
the type of emitter and the parameter 963 "With prim
control/prim pump" must be set to "yes" to switch on the
pump for the second zone.
Example
Zone 1: Heating/cooling fl oor
Zone 2: Fan coils
Zone 1: Heating/cooling fl oor
Zone 2: HCF
Warning
If these settings are not chosen properly the heat pump
may stop automatically due to the fl ow temperature
being too low. A safety mechanism is triggered at 6 °C
to protect the exchanger from freezing.
Actuator running time
For the 3-position servomotor used, it is possible to
adjust the travel time. With a 2-position servomotor,
the adjusted travel time is inoperative.
Mixing valve in heating mode
Determines the position of mixing valve 1 (Y1 / Y2)
during heating operation is activated.
This parameter is inoperative in installations where
heating and cooling circuits are hydraulically separate.
• Control
The valve controls in heating and cooling mode.
• Open
The valve controls in cooling mode, and is open in
heating mode.
Waterstage / Maintenance Manual / 2105 - EN
Confi guration
938 = 10 °C,
with 924 = 18 °C
963 = yes
938 = 0 °C,
with 924 = 18 °C
963 = yes
With prim controller/system pump
Line Nr
963
This setting specifi es whether the cooling circuit is
supplied from the primary controller or from the primary
pump (depending on the installation). It can also be
used to provide cooling to the second zone.
Warning
In the case of a radiator or any other emitter which does
not support the cooling mode in zone 2, this setting
must remain on "No".
How the confi guration aff ects control
with a 35 °C outdoor temperature the fl ow setpoint
will be 18 °C – 10 °C i.e. 8 °C.
while in the fi rst zone (HCF) it will be 18 °C through
action of the mixing valve.
with a 35 °C outdoor temperature the fl ow setpoint
will be 18 °C in both zones.
Programming line
With prim contr/system pump (no / yes)
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