Assuming the valve being controlled has limit switches which will signal a
fully open, or fully closed position, the 2403 Valve Status Module operates in
the following manner:
If the valve is
closed, the green CLOSED indicator will be lit. If the OPEN-CLOSE-AUTO
pushbuttons are indexed to the AUTO mode, and an external contact closure
signals the valve to begin to open, the red OPEN indicator will begin to flash
intermittently indicating the valve is to travel to this position.
As the valve begins
to open, the green CLOSED indicating lamp will glow steadily, until the valve is
fully open. When the valve is fully open the TRAVEL lamp will go out and the
red OPEN indicating lamp will glow steadily.
When operation is
reversed and the valve is to close, the red OPEN indicator goes out, the green
CLOSED indicator flashes, and the amber TRAVEL light glows steadily. When the
valve reaches a fully closed position, the amber TRAVEL light will go out and
the green CLOSED light will go from a flashing to a steady state condition.
A time delay valve
failure monitoring system is standard equipment, and is field adjustable from
0.2 to 60 seconds. If the valve dies not operate within the specified time, the
red FAIL indicating light will come on steadily. When coupled with the Essex
Model 2401 Alarm Module, the red FAIL indicator on the 2403 will flash and an
audible alarm will sound from the 2401. By pushing the alarm button on either
the 2401 or 2403, the alarm the alarm light will glow steadily.
An optional failure
relay is available to activate external devices should a valve fail.
are included on the OPEN-CLOSE-AUTO pushbuttons to provide remote monitoring of
these switches, or to provide the capability for interlocking. By using the
electronic CONTROL output, or the FAIL output, a remote 24V DC relay can be used
to provide additional contacts and higher current ratings where needed.