Danfoss EKC 316A Reference Manual page 12

The diagram is a simplified form of the EKC 316A algorithm,
where sections (1) and (2) have been added in connection with
modifications made in software version 1.24.
Sections (1) and (2) are active when parameter o10 is set to 5
or 6, and in this situation, the analogue current signal applied
to terminals 16 and 17 in certain circumstances can control the
opening degree OD% of the valve. With o10 set to 5, a current
signal 0 to 20mA can be applied to terminals 16 and 17. Similarly a
4 to 20mA signal can be used when o10 is set to 6.
When the sections (1) and (2) are active, the function in section
(2) will choose the lowest value of OD%, that comes from either
sections (1) or the PI Control.
This means that the valve can be manually controlled by the
external analogue voltage as long as the output of section (1) is
smaller than the output from the PI Control section. If output of
the PI Control section is smaller than the output from section (1),
then the valve opening degree OD% will regulated according to
superheat values and MOP setting. This prevents excessive values
of opening degree OD% that might cause low superheat values or
high suction pressure.
The opening degree OD% will go to zero if there is a fault in any of
the sensors.
12 Reference manual RS8ED102 © Danfoss 03-2006 EKC 316A