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Page 11
Multi-Point Process Switch
EX-1711
Preliminary Troubleshooting
Relay does not energize . . . LED indicator is not
illuminated
Disconnect 115 Vac power from MULTI-POINT Process
Switch and check internal fuse. If fuse is blown, replace
(see Page 6).
Check that 115 Vac power is properly connected to input
terminals and power circuit is “on”.
Relay remains energized . . . LED indicator does not
turn off
Relays and LEDs remain energized whenever input signal
(mAdc) is greater than the set-point value. If a low level
set-point is required to actuate a pump or to close a
valve, re-wire circuit at relay using the N.C. (normally-
closed) switch contact.
Unusually high load resistance (RL) at Process Switch
Possible short-circuit in signal loop. If signal current
exceeds 70 mAdc, an overcurrent-limiting PTC (PTC—
positive temperature coefficient) resistor restricts current
levels through the entire loop to only a few milliamps.
Relay remains energized too long
Deadband is adjustable over an extremely wide bandwidth
(1.0%–12.5% FS). An adjustment to the deadband may
create a situation where the relays will remain energized
much longer than desired. (See Page 9)