LEAD/LAG OPERATION
The Mercoid
®
MPC pump controller is designed to easily operate a pair of pumps in the
most efficient manner possible. The controller has a 'lead/lag' feature that allows two
pumps to operate in an alternating fashion to minimize wear.
The Mercoid
®
MPC pump controller has a pair of set points each for pump 1 and pump 2. If
the lead/lag feature is turned off,
SP1H
and
SP1L
control pump 1 and
SP2H
and
SP2L
control
pump 2. If the lead/lag feature is turned on, pumps 1 and 2 will be controlled in the
alternating fashion described below. In all cases the P1 lamp will indicate activity of pump 1
and the P2 lamp will indicate activity of pump 2. The lead/lag operation is set in the Secure
menu with the item
LdL9.
Lead/Lag On
After installation, set the
SP1H
to the high level (pump on point) for standard operation. Set
SP1L
to the low level (pump off point). Set the
SP2H
to the level where you want BOTH
pumps to turn on (emergency pump on). Set the
SP2L
to the level where you want the
second pump to turn off (emergency pump off).
The controller will not allow you to set
SP1H
below
SP1L
,
SP1L
above
SP1H
,
SP2H
below
SP2L
, or
SP2L
above
SP2H
. The controller will not allow you to set any set point or alarm
point above or below the programmed scale. No error messages are generated. The
displayed value will stop at an allowable point just above (or below, as the case may be)
the maximum or minimum allowed.
In normal operation, when the
SP1H
point is reached, one of the pumps will turn on. When
lead/lag is turned on, pumps 1 and 2 will alternate. If the level reaches the
SP2H
point, both
pumps will be turned on until the
SP2L
point is reached, where one of the pumps will turn
off. When
SP1L
is reached, remaining running pump will turn off. The last pump off will not
be the next pump on.
Lead/Lag Off
If lead/lag is turned off,
SP1H
and
SP1L
control pump 1 and
SP2H
and
SP2L
control pump 2.
There is no alternating function.
SEAL FAILURE OPERATION
The Mercoid
®
MPC Pump Controller is designed to work with most types of submersible
pump moisture sensors to detect outer seal failure. Most often the moisture sensor is a
conductance device that detects moisture in the oil chamber indicating an outer seal failure.
Using a 2.5 VDC power supply sent to the moisture sensor the MPC Pump Controller
monitors the resistance between the probe lead wires or the single probe lead wire and
ground. The resistance set point is adjustable over the range of 10K to 500K ohms
adjustable in 10K ohm steps, and is set with Secondary menu items
SFS1
and
SFS2
. When
the resistance of the moisture sensor decreases below the resistance set point the MPC
controller goes into the programmed seal failure mode.
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