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Building Technologies
Basic Documentation LMV27...
CC1P7541en
7 Basic unit LMV27
17.12.2018
7.5.3.10. Continuous fan
With burners that can be damaged by heat (e.g. several burners using the same
combustion chamber), continuous purging may be required. In that case, the fan
operates continuously in all phases.
For that purpose, the fan motor contactor is to be connected to X3-05, pin 3, tapped
after the unit fuse and the safety loop.
For checking the air pressure switch, a pressure switch relief valve must be connected
to fan motor contactor X3-05, pin 1. When output X3-05, pin 1, is activated, the relief
valve diverts the fan pressure to the air pressure switch and, when deactivated, ensures
that no pressure is fed to the switch.
Example:
LMV...
Bild 296e/1010
X3-
0
5
X3
-0
2
Figure 34: Continuous fan