Evoqua WALLACE & TIERNAN SFC SC, Original Manual

Page: 21 / 82

SFC SC
Functions
4.
21
4.3 Outputs
4.3.1 mA output
The mA output of the SFC SC is electrically isolated and can be
parameterized to 0 – 5 mA, 0 – 10 mA, 0 – 20 mA or 4 – 20 mA in
the menu. Any of the values or Y
out
actuator outputs can be
assigned to the mA output.
4.3.2 Relay outputs
The SFC SC has two relays, each with a two-way switch. These
switches perform various switching tasks, depending on the
selected actuator. The relevant circuit diagrams are provided in
the appendix in 9. “Wiring Diagrams”. In order to switch larger
inductive load, we recommend installing an additional contact
such as a contactor or load relay, in order to guarantee the
contacts have a longer service life.
The relay contacts are protected by RC circuits ex works. These
provide radio interference suppression for inductive loads such as
pumps, motors, etc.
Connection of small loads
When connecting small loads to the mains voltage, e.g. contactors
or positioners with low power consumption (e.g. V10K), the
closed-circuit current via the RC circuits can suffice to activate the
loads (humming of the positioner, contactor is not deactivated,
etc.). In this case, the plug-in jumpers of the relevant contacts
should be removed to deactivate the RC circuits.
K1 J6/J7
K2 J8/J9
Picture 1 Relay outputs
A Plug-in jumpers
A