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Manual RS8CS302 © Danfoss 07-2005
EKC 315A
Appendix 5
Standby temperatures for TQ valves.
TQ valve
The valve’s actuator temperature is limited, both when regula-
tion is stopped and when the valve is right out at the opening
point and closing point.
(The opening and closing points may fluctuate a couple of de-
grees up or down, depending on pressures and tolerances).
n26
The setting is based on the TQ valve’s closing curve. With a plus
value the valve can be kept slightly open. With a minus value the
valve can be closed completely. If the minus value is high you
can be sure that the valve will close, but then it will also react
slowly when it has to open again.
n27
This setting defines the number of degrees the actuator has to
be warmer when the valve is completely open. If the value is
high you can be sure that the valve is completely open, but then
it will also react slowly when it has to close again.
Appendix 6
The two types of regulation for superheat are, as follows:
Adaptive superheat
Regulation is here based on the evaporator’s load by means of
MSS search (MSS = lowest permissible superheat).
(The superheat reference is lowered to the exact point where
instability sets in).
The superheat is limited by the settings for min.and max.super-
heat.
Load-defined superheat
The reference follows a defined curve.This curve is defined by
three values: the closing value, the min. value and the max.
value. These three values must be selected in such a way that
the curve is situated between the MSS curve and the curve for
average temperature difference
∆
Tm (temperature difference
between media temperature and evaporating temperature.
Setting example = 4, 6 and 10 K).