Pump on demand can be used on hydraulic positional
systems and refers to operating a pump to open and/or
close the actuator. To use pump on demand features,
Pump On Demand must be turned active.
If Run Pump To Opn is active then when the actuator is
opening Pump Output is set active.
If Run Pump To Clse is active then when the actuator is
closing Pump Output is set active.
In certain cases the pump is required to continue running
for a set time once the actuator has stopped moving,
either to prevent constant stop/start of the pump, or to
build pressure at the actuator limits.
To use this feature Pump Run On time should be set to
the required run on time and once the actuator is stay
put, the Pump Output will be held active for the duration
of the run on time. If a pump run on is not required then
the Pump Run On time should be set to zero seconds.
Pump on pressure can be used on hydraulic positional
systems and refers to operating a pump to maintain
pressure in an accumulator. To use pump on pressure
features, Pump On Pressure must be turned active.
Two methods of maintaining pressure can be used –
using a pressure transmitter or using pressure switches.
If using a pressure transmitter then Press Swtch Ctrl
should be turned off and Accum Pressure should be
linked to an analogue input to indicate the accumulator
pressure.
Four pressure set points can be set to provide actions
based on the accumulator pressure.
Pump Start SP is the minimum desired accumulator
pressure. Pump Stop SP is the maximum desired
accumulator pressure. When Accum Pressure drops
below the Pump Start SP, the Pump Output is latched on
and will remain on until Accum Pressure rises above the
Pump Stop SP at which point the Pump Output will be
turned off.
Low Pressure SP is a low pressure alarm set point which
is used to indicate that the pump is not able to build
pressure in the accumulator. If the Accum Pressure
drops below the Low Pressure SP for greater than Px
Limit Delay then Low Press Fault output is set active. If
Fail On Pump Flt is active then the actuator will position
based on the fault override settings.
High Pressure SP is a high pressure alarm set point which
is used to indicate that the pressure has exceeded the
maximum allowable accumulator pressure possibly
caused by the pump continuously running. If the Accum
Pressure rises above the High Pressure SP for greater
than Px Limit Delay the High Press Fault output is set
active.
If using pressure switches to control accumulator
pressure then Press Switch Ctrl should be set to active.
If using a single pressure switch then Single Px Switch
should be set active and the pressure switch must be
linked to Pump Start Swtch. The application
automatically sets Pump Start Swtch and Pump Stop
Swtch active and off based on the single pressure switch
status.
If using two pressure switches then Single Px Switch
should be turned off, the switch indicating low pressure
should be linked to Pump Start Swtch and the switch
indicating high pressure should be linked to Pump Stop
Swtch.
For both cases, if the Pump Start Swtch is active for
greater than Px Limit Delay, the Pump Output is latched
on and will remain on until the Pump Stop Swtch is
active for greater than Px Limit Delay at which point the
Pump Output will be turned off. The Px Limit Delay can
be increased to prevent signal noise causing the pump to
start and stop frequently, or set to zero to cause the
operation to be instant.
For both pressure switch control and pressure
transmitter control, if Manual Stop Pump is active then
when the controller is in Manual mode and the switch is
in the centre, Pump Output is set off. This is such that if
there is an issue with the pump, the pump can be
stopped instantly by going into Manual mode.
NOTE: If in Manual mode, Manual Stop Pump is active
and the switch is turned either away or towards the
pump will operate as normal such that pressure can be
built in the accumulator when trying to position the
actuator.
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