Switches - Which Way Up?

[jsharkey]

How do you know which way up to mount the breaker switches supplied by Van's such that "down" is "off" per US convention?
Jim Sharkey
RV6 - Getting there!

[gmcjetpilot]

Originally Posted by jsharkey

How do you know which way up to mount the breaker switches supplied by Van's such that "down" is "off" per US convention? Jim Sharkey RV6 - Getting there!

Just get out your ohm meter or continuity tester and check. If you get continuity or low resistance (like a few ohms), that is the ON position. Put a little dot on the case as a reminder. I assume there's a KEY way in the threaded mount? Once you figure out which way is on they should all be the same.

The next question you might ask, does it matter what wire goes on what terminal of the CB/switch? Usually no, but sometimes CB's are marked with load & source, source being battery/buss. It will work either way; there is no polarity for a fuse or CB usually, but follow the manufactures instructions.

On larger planes with overhead toggles it gets more confusing. On older Boeing aircraft Fwd is ON and I believe Douglas is opposite. New Boeing overheads are mostly push button and rotary dial switches.

[n815vp]

I just position the switch or breaker so that the breaker rating on the lever or breaker button is up.
Watch the Vans battery master switch. It has no marking.

[jsharkey]

All good stuff that I should have worked out myself - but the sense of community makes it worth asking the questions.
Jim Sharkey

[uk_figs]

Just a quick note, if you use B&C switches the B&C 1-2 on/off switch is inverted from the rest and with keyway up and the toggle down the contacts are closed (i.e the switch is ON). If you use a 1-3 instead you get the same functionality but also the correct keyway orientation.