Minor Faults, Causes And Remedies - ProMinent mikro g/5a Instruction Manual

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ProMinent mikro g/5a
Precision feeding pump
Suction capacity
The maximum suction lift of the ProMinent
liquid end filled is 4-6 m depending on the type of pump (see technical data).
The suction capacity with the liquid end empty is lower (see technical data).
The pump cannot prime against a head.
If the pump feeds into a pressurised system and has accidentally sucked in some
air, this air will only be compressed in the liquid end and no feeding will take place.
In this case the bleed screw on the back-pressure valve is opened about half a turn
and is bled by quick priming (simultaneously pressing the Up and Down keys) until
the suction line and liquid end are filled, free of bubbles. Then retighten the bleed
screw.
If a float switch with early warning is used, the pump will switch into the early warning
status if the first switch point is reached. When the second switch point is reached
(after about 20 mm) the pump switches off so that no air can enter the line system
or the liquid end.
There is opening pressure at the suction and, if the fluid level in the chemical tank
in the operating mode is located above the metering pump and if there is a pressure-
loaded suction line. In this case the back-pressure should be so high that a minimum
differential pressure of 1.5 bar exists. Otherwise an additional back-pressure valve
or a spring-loaded injection valve with an appropriate opening pressure is to be
used.
Important: A back-pressure valve or a spring-loaded injection valve is not a device
which closes absolutely tightly. For this reason the suction side must be fitted with
an isolating valve which is closed when the pump is at a stillstand.
In order to change an output flow which has been set and possibly confirmed by
calibration and to return to the exact same original value, changing the stroking rate
is an option as this is digitally processed and reacts totally linear without mechanics.

3.4 Minor faults, causes and remedies

Pump does not prime in spite of full stroke
movement and proper air bleeding:
Crystalline deposits due to valves drying out. Take suction hose temporarily out of
the chemical tank and rinse out feeding and well. If there is no improvement
disassemble valves and clean them.
Pump does not move, yellow LED does not illuminate,
no indication in the LCD readout:
Check the mains voltage. Have the fuse checked by authorised customer service
personnel and if necessary have it exchanged.
Caution: Only use types which suit the voltage shown on the name plate. If the fault
cannot be remedied by replacing the fuse, have the electronic circuit or whole pump
checked in the factory.
No flow output although yellow indicating light
is flashing:
The stroke lenght is set to zero or too low a valve. Increase stroke length by means
of the stroke adjusting knob (2). Air could have been trapped in the liquid end. This
can be remedied by bleeding as described in section "Suction capacity" (2.3).
Instruction manual
mikro g/5a
®
mikro g/ 5a metering pump with the
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