Possible Faults; Maintenance; Maintaining The Servomotor; Disposal - Grundfos Vaccuperm VGS-141 Montage- Und Betriebsanleitung

6.10 Possible faults

Fault
Despite constant operating
conditions the vacuum varies
Despite constant operating
conditions the dosing flow varies
Leakage at the rate valve
Floater of the measuring tube is
not caught
Desired dosing flow is not
reached
Despite correctly displayed gas
flow the desired gas solution
concentration cannot be reached
Servomotor does not run
Servomotor does not reach the
whole range desired
Servomotor runs in wrong
direction
The adjusting spindle falls from
the "automatic" position into the
"manual" position unintentionally

7. Maintenance

Rates for cleaning and maintenance
• at least every 12 months
• in case of malfunction

Warning

Do not open the components of the device!
Cleaning, maintenance and repair only by authorized
personnel!
Warning
Switch off the whole plant before doing cleaning and
maintenance work!
Danger of gas break-out!
Warning
Check the tightness before restarting!
Danger of gas break-out!
26
Cause
Spring in differential pressure regulator is soiled
Spring in differential pressure regulator is
damaged
Diaphragm in differential pressure regulator is
soiled
Diaphragm in differential pressure regulator is
damaged
Bar gasket in the rate valve damaged
Measuring tube is soiled
Insufficient injector vacuum
Servomotor (option) does not reach the 100 %-
position
Leakage in vacuum line between differential
pressure regulator and injector
Vacuum line between differential pressure
regulator and injector too long
Vacuum line between vacuum regulator and gas
dosing system too long
Admission pressure at the vacuum regulator too
low
Regulating channel of the adjusting plunger soiled Call the service
Leakage in vacuum line between vacuum
regulator and gas dosing system
Servomotor is switched to manual operation
Servomotor resp. electronics adjusted wrongly
Servomotor resp. electronics adjusted wrongly
The spring-loaded thrust pad has been displaced
and therefore cannot deliver enough preload to
the holding groove of the adjusting spindle.
The spring-loaded thrust pad is damaged.
Correction
Call the service
Call the service
Call the service
Call the service
Call the service
Clean the measuring tube
Check injector, observe the manual of the
injector
Call the service
Eliminate leakage (see "checking the tightness")
Observe table "Recommended diameter" in
chapter 2.7
If necessary, open gas supply or clean filter
(observe manual of the vacuum regulator)
Eliminate leakage (see "checking the tightness")
Switch servomotor to automatic operation
Call the service
Call the service
Adjust the thrust pad.
Exchange the spring-loaded thrust pad
(96690346 or 50.1340); gently press on the ball.
The adjusting spindle must be able to move up
and down.

7.1 Maintaining the servomotor

The servomotor features permanent lubrication and
Note
is maintenance-free.
Warning
The entire installation should be switched off before
any repair work is carried out.
Disconnect the mains voltage before opening the
housing!

8. Disposal

This product or parts of it must be disposed of in an
environmentally sound way:
1. Use the public or private waste collection service.
2. If this is not possible, contact the nearest Grundfos company
or service workshop.