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WITT-GASETECHNIK GmbH & Co KG
Salinger Feld 4-8
: +49 (0)2302 89010
www.wittgas.com
Gas Safety- & Control Equipment
D-58454 Witten
Fax: +49 (0)2302 89013
witt@wittgas.com
7.4
Checking inlet filters for blockages
7.4.1
Plug filters (for version MG 50, MG 100, MG 200)
To check these proceed as follows:
First take the gas mixer out of operation.
Undo supply pipes on the gas inlet connections.
Pull out and clean the filters (e.g. blow out with N
2
) and refit, or, if necessary, replace (only
genuine spare parts).
7.4.2
Screwed filters (for version MG 200, MG 500)
We recommend to check these in case of a pressure drop between the supply pressure and inlet
pressure of 0.6 bar. Proceed as follows:
First take the gas mixer out of operation.
Unscrew the filter receiver, loose the hex-nut and pull out the filter element.
Clean the filter element (e.g. blow out with N
2
) and refit, or, if necessary, replace (only genuine
spare parts).
Fix the filter element with the hex-nut. and consider a perfect sealing of the O-rings.
Screw on the filter receiver.
7.5
Functional check on the electrical equipment
A simple functional check on the electrical equipment (pressure switch / transmitter, alarm module
and audible alarm device) is to be simulated every six months by means of insufficient pressure.
Proceed as follows:
Switch on the unit electrically.
If there is no gas pressure or the gas pressure is below the minimum pressure, an according
error message is shown on the LCD display.
In the case of the
GB
version an audible alarm device sounds and the solenoid valve in the
outlet closes.
If this is the case, deactivate the related alarm circuit by pressing the corresponding „OK/ON“
button.
Then increase the gas pressure to the stipulated minimum pressure and reactivate the alarm
monitoring.
If the visual, and in the case of the
GB
version also the audible warning, is now not triggered,
the unit is ready for use.
7.6
Setting the receiver pressure
If a pressure switch is used in position
(29)
, the receiver pressure is set at the pressure switch.
Please refer to the separate instructions of the pressure switch in the appendix (Section 9).
If a pressure transmitter is used in position
(29)
, the receiver pressure is set at the alarm mod-
ule (see Section «2.3», separate alarm module manual).
In the case of gas mixing units
PvDu
and
GB
versions, the pressure switches on the inlet connec-
tions must also be reset if the pressure ratios are adjusted upwards.
If pressure transmitters are used on the inlet connections the pressures are set at the alarm mod-
ule (see Section «2.3» separate manual of the alarm module).
PvDu
GB
PvDu
GB
