10
Mode 1 Start Pressure
The start pressure can be set to any value from 1 kPa to 2000 kPa or from 1 psi
to 290 psi in increments of 1 kPa or 1 psi. Normally the start pressure would be
set to the pressure at which you want the pump to start. In normal operation each
time pressure drops to whatever value you have set, the pump will start. Once
running the pressure can fall to below the value you have set and the pump will
continue to run. In fact if you have not set the trip pressure to some value greater
than zero, the pump will continue to run in spite of a complete lack of pressure.
The start pressure can be set as low as 1 kPa or 1 psi and the E30 will function in
the manner described above. If you choose to set the start pressure to zero you
will invoke a warning message from the E30 to check your pressure settings. The
E30 will not tolerate having its start pressure set to zero. The start pressure must
always be set to a higher pressure than the trip pressure. If you have set the trip
pressure to zero and you also set the start pressure to zero then both pressures
would be the same and the E30 will not tolerate this and will display a message
telling you to check your pressure settings.
Mode 1 Stop Pressure
The stop pressure is the pressure at which the E30 will shut down the pump in
normal operation. It must be set to some value that is higher than start and trip
pressures. The range of adjustment is zero to 2000 kPa or zero to 290 psi in
increments of 1 kPa or 1 psi. If you attempt to set the stop pressure to a value
that is less than the start or trip pressures you will invoke a warning message from
the E30 to check your pressure settings.
The stop pressure can be set to a minimum of 1 kPa or 1 psi higher than the start
pressure and the E30 will function. Normally you would set the difference between
the starting and stopping pressures to some value that is much greater but for
some special applications the close operating differential capability of the E30 is
an invaluable feature and can be used in some circumstances as an alternative
to the single point snap action pressure switch described in mode 3.
Mode 1 Anti-Cycling
Electric motors are often limited in the number of times they can be safely started
in an hour. This is particularly important in the operation of submersible bore
pumps. When a motor starts there is an initial inrush of current that produces
heat in the coils and iron rotor of the motor. If the frequency of starts is excessive
the accumulation of heat within the motor can cause severe damage and eventual
failure of the motor. Submersible bore pump motors are particularly prone to
damage from excessive cycling (starting and stopping).
