A common misconception is that fuses or circuit breakers protect devices.
Not so. The protection is for the wire, or more precisely, the insulation
on the wire. A given wire-insulation combination can carry a certain
maximum current for a specified maximum temperature increase, and circuit
protection devices are selected on this basis.
If in your example the wire is both short in length and physically protected
---From contacting anything that could make a short circuit in the event the
insulation is compromised, protection in the form of a fuse or CB is not
required.
Best regards,
Rob Housman
Europa XS Tri-Gear A070
Airframe complete
Irvine, CA
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com]On Behalf Of Simon Smith
Subject: Europa-List: Wiring query
Hi all,
I have virtually completed the wiring in accordance with the diagram on
Page 25-11 issue 4 which I believe is the latest version. I am using a
battery isolator and, after discussion with Andy, I have swapped the 30amp
slow blow fuses on the battery feed and regulator feed to 25 amp CB's.
I crossed my fingers and powered it up and fortunately everything seems to
work. One thing that I have noticed though is that 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?
Cheers
Simon
#504 G-BZTN
80% done 90% left to do!
|