Supplied By www.heating spares.co Tel. 0161 620 6677
24
DOMINA PLUS F 24 - 30 E
FERELLA EXTRA F 24 - 30 MEL
Version - 09.2002
Air pressure switch
This is used to check whether the fumes are adequately evacuated. The pressure switch compares the static
and dynamic signals coming from the pressure test points on the fan according to the figure. The pressure switch
is connected to the card and is normally open (see diagram). Before the card initiates the ignition procedure
(opening the valve, etc.), you must make sure that the fan works properly and that the air pressure switch
ensures this by closing its contacts. This happens if the difference in pressure is 165±15Pa. So the signal must
be at least 180Pa. To open its contacts again, the difference in pressure must drop under 150±13Pa. To perform
checks on contact opening and closing, it is always recommended to check directly on the card (X5 - 3/4).
Checks
It is necessary to check:
·
Whether the electrical connections are correct.
·
Whether the pressure test point pipes are clean and contain no condensation water.
·
That the signal is open when the fan is not working.
·
That the pressure is at least 180Pa and that above this pressure the pressure switch closes its contacts.
·
If the signal is low, it is necessary to check that the fume diaphragm is correct, the fan has 230V, the pressure
test points are properly inserted and the Venturi tube has no burrs of any kind. Lastly, check that the ends
of the pipes are not obstructed.
N.B. The pressure difference must be measured with the airtight chamber closed. The pressure gauge
connections can come out through the hole, which is closed by a silicone plug, on the front of the cover.
C
NC NO
Pressure
gauge
pa
Key
NO =
Normally open
NC =
Closed
C =
Common