The Essex 2402 Pump Status Module operates in the following manner:
Assuming the pump is in the off condition, the green OFF indicator is lit. If
the HAND-OFF-AUTO pushbuttons are indexed to AUTO, and an external contact
closure occurs which enables the pump or motor to start, an amber CALL indicator
will light. Once the pump starts, an auxiliary contact on the motor starter
pressure switch, flow switch, etc. sends a "report back" signal to the 2402
causing the red RUN light to come on and the green OFF indicator and amber CALL
indicator to go out.
If the pump fails to start, or fails to stop within a 0.2 to 60 second field
adjustable time, the red FAIL lamp will flash, indicating trouble and an
optional external horn will sound. Depressing the ALM/SIL button will silence
the horn and cause the FAIL indicator to light steadily.
If the HAND-OFF-AUTO pushbuttons are indexed to HAND, an amber CALL indicator
will light and the unit will operate as described above.
Auxiliary contacts are included on the HAND-OFF-AUTO push buttons to provide
remote monitoring of these switches, or to provide the capability for external
interlocking. Field selectable power up or control input timing is standard.
This provides staggered starting of unit after a power failure or delayed
starting each time the unit is activated. All indicators light for
approximately 1 second on power up or can be checked at any time using ALM/SIL
All of the switches and indicators on the instrument face are sealed for ease of
cleaning and the prevention of switch contamination from grease, dirt,etc...Units
are provided with a custom engraved label identifying the use of the Pump Status