Message text written by INTERNET:forum@europaclub.org.uk
>My 914 manual sez ground the 'mag' wire shields at the engine end
only.<
Although both ends is advocated by Europa to ensure grounding there are two
good reasons to ground at one end only:
1. To reduce the risk of interference from ground loops.
2. Should another ground between the engine and panel fail if the mag lead
is grounded at both ends an electrical fire could start due to this wire
trying to provide an earth return at much higher currents than it is
designed for. This has actually happened at least once.
Whilst grounding the mags is important for safety any failure would
instantly show up at shutdown. Also with Rotax engines the rpm needed to
start the engine is much in excess of that achieved by turning the prop
slowly by hand so the danger is already minimised. With dual grounding no
failure would show up anyway until the second connection fails.
Nigel Charles
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