Steve,
Yes, physical protection includes everything necessary to prevent the
insulation being breached. This includes the routing of any slack in the
cables to allow you to remove the panel and disconnect the cables -- where
does the slack cable rest when the panel is refitted? Could it be pinched,
or chafe on anything?
Since you raise the subject of firewall penetration, I strongly commend Bob
Nuckolls' AeroElectric Connection and his website
http://www.aeroelectric.com. Look for the article on firewall penetration.
You may not wish to use quite as elaborate a form of protection as required
for certified aircraft, but he clearly recommends Firestop/Firesleeve to
withstand the full 2000 degrees F of a fuel fire. I suspect silicone
compound may not match this.
Just to clear up a further point from the comments following Simon's
original posting, the battery isolator solenoid circuit is indeed
permanently connected to the positive side of the battery, but it is not
'energised' until the ground connection is made by the master switch. I'm
sorry this was not clear from my previous response. On an aircraft this is
usually the only power (as opposed to avionics control, e.g. PTT) circuit
where the switch is on the ground side. Because the isolator is normally
located immediately adjacent to the battery, no electrical circuit
protection is needed, although good physical protection such as neoprene
covers should be provided on any terminals that are permanently live.
Regards
Mike
Europa Club Safety Officer
Mike - when you say 'physical protection' are you talking about anti
chaffing or 'p' clip support? I have put both of my cbs in the panel but
have tried to anchor every 3-4''.
Where I breach the firewall I have put in a proper bulkhead seal which I
will fill with silicone once the panel is finally in.
Steve Pitt #403
>
> The wiring to engage the isolator is not given a fuse or circuit breaker
to protect it because it is on the ground side of the device. In contrast,
there is protection for the starter relay solenoid circuit because that is
supplying a positive to cause it to engage.
>
>
> if the batt master CB is pulled, power is removed from the aircraft but
the isolator remains energised (which I think is correct according to the
diagram). Does it matter that there is no fuse/cb protecting the isolator?
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