The remote switch can be installed some distance from the F29. The
maximum distance is limited by cable resistance and capacitance. The total
cable resistance must not exceed 5K Ohms with the remote switch closed.
The total capacitance of the cable must not exceed 25nF with the remote
switch open. Wires to the remote switch should be run separately from
power carrying cables. Do not run the remote switch wires in a conduit that
also contains power cables. Capacitive coupling between the adjacent
cables may cause false triggering of the F29’s remote input. For cable runs
longer than 150 metres we suggest using 2 separate wires to reduce
capacitive coupling between the adjacent wires. When set up this way
cable resistance becomes the limiting factor for distance. The table below
sets out the resistance of typical copper wire of various diameters.
Note that the cable resistance refers to the total resistance out to the
remote switch and back, as measured at the controller across the 2 remote
connection wires with the external remote switch closed.
A mains voltage rated external switch with voltage free contacts such as a
pressure switch, tank level switch or a set of external relay contacts can be
used to control the F29. The supply to the external switch must be taken
from the LV terminal of the F29 when the controller is powered from the
mains or from a 24V source. The F29 must always be powered from the
same source as the supply to external switch. The supply to the remote
switch on the F29-12 (low voltage DC model) must be taken from the
supply positive terminal. In all cases the external switch return wire must
be connected to the Remote input (R) terminal on the F29. Relative to
neutral, the supply to the external switch will range from 12 to 24 VDC or
from 20V to 35V AC depending on the supply voltage.
WARNING:
Never connect an external power source of any kind to the F29’s
remote input terminal.
WARNING:
The low voltage source available at the LV terminal is non-
isolated and must be regarded as operating at full mains potential whenever the
F29 is powered from the mains. Relative to earth, the LV terminal is at mains
potential.
REMOTE INPUT
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