60 amp Circuit Breaker for RV-7A

[Dave Cogan]

I am using 2 x rows of the push pull circuit breakers (that look like the Klixon 7277-2 series) All black including the screw thread with a white number indicating the amp rating.

As I will have a 60 amp altinator I need a 60 amp CB.

The problem is the only 60 amp CB I can find is either the Klixon 6752 100 series which seems to have 2 x small screw either side of the push/pull knob or the 60 amp type that has a WHITE plastic pop out that you can't grab by your hand and manually pull out.

In other words my 60 amp CB is going to look different to all the others.

Any suggestions of finding one that is all black, pull out/push in, with 60 written in the middle in white numbers?

[jbDC9]

I feel your pain; went through this myself a year and a half ago. Take a look at this thread, might be some useful info there; http://www.vansairforce.com/communit...ead.php?t=5527

For what it's worth, I went with the 60 amp pullable from McMaster-Carr. It's kinda pricey at 50 bucks, but looks the part and all is well with mine at 190 hours total time. Go to http://www.mcmaster.com/ , search for p/n 6608T1 and you'll see it.

[uk_figs]

how about using a current limiter and no 60A CB in the cockpit. There are a number of threads on this subject that you can search for

[N941WR]

Dave,

There is one more option...

Put an ANL fuse on the firewall. That way you won't have to run that big wire up to the panel and back.

Check Dan's site, he has some good pictures of this.

[AltonD]

I am going to use the current limiter form B&C

http://www.bandc.biz/cgi-bin/ez-cata...58218#c905-100

You will need the base as well as the limiter

[Gsuit]

Originally Posted by Dave Cogan

I am using 2 x rows of the push pull circuit breakers (that look like the Klixon 7277-2 series) All black including the screw thread with a white number indicating the amp rating.

As I will have a 60 amp altinator I need a 60 amp CB.

The problem is the only 60 amp CB...

Originally Posted by AltonD

I am going to use the current limiter form B&C

http://www.bandc.biz/cgi-bin/ez-cata...58218#c905-100

You will need the base as well as the limiter

Ditto on the ANL current limiter.

[gmcjetpilot]

Originally Posted by Dave Cogan

I am using 2 x rows of the push pull circuit breakers (that look like the Klixon 7277-2 series) All black including the screw thread with a white number indicating the amp rating.

As I will have a 60 amp alternator I need a 60 amp CB.

The problem is the only 60 amp CB I can find is either the Klixon 6752 100 series which seems to have 2 x small screw either side of the push/pull knob or the 60 amp type that has a WHITE plastic pop out that you can't grab by your hand and manually pull out.

In other words my 60 amp CB is going to look different to all the others.

Any suggestions of finding one that is all black, pull out/push in, with 60 written in the middle in white numbers?

KEEP THE PULLABLE CB IN THE COCKPIT, GOOD IDEA. Go with the 100 series. That is what I have and it mounts up in its own little spot FAR RIGHT and the rows of CB's (7277-1) are in their happy home along the bottom right panel.

This may or may not help you, but you could get by with 50 amp CB if the total load is less. What is you max current load? Take the flaps, lights, heated pitot, 7 amps for battery charging (usually much less) and microwave and the sum is? If its less than 50 amps you can use a 50 amp CB. You really don't want to run your 60 amp alterantor at 60 amps. I am not suggesting you undersize the CB, but if you total load is say 45 amps (including 5-7 amp dead battery charge) a 50 amp CB (or what ever size your load indicates) is good enough. There seems to be jump in CB case size (and cost as well) with CB's over 50 amps. +50 amp range means more heat & the need for a bigger case.

Originally Posted by AltonD

I am going to use the current limiter form B&C
http://www.bandc.biz/cgi-bin/ez-cata...58218#c905-100
You will need the base as well as the limiter

Current LIMITER? ha-ha That's a fancy word for a FUSE, a big fat remote fuse. I know Bob of Aeroelectic promotes this remote FUSE under the cowl deal. It does have some advantages, like one less wire run of about 2 or 3 feet (to a panel mounted CB). That is it. In general Bob is a fuse-man. Nothing wrong with that, but if going CB's (like 100% of the planes in the world) than go CB. Put that BIG FAT CB IN THE PANEL!

Bob makes good points for this FUSE set-up, but I disagree that its for "noise control". No mater where you run the B-lead or if you use a FUSE or CB, its electrically connected to the airplane, including inside the cockpit. The location of fuse/cb is not critical to noise. If the alternator/regulator are making noise you will hear it regardless. Back in the OLD days regulators where "noisy", but modern alternators and regulators are not. If there is alternator noise there is a problem with it or there is a poor ground.

[w1curtis]

I know there is an off (read very, very, small) chance where pulling the field breaker will not accomplish the same thing as having a pull-able breaker for the alternator B lead itself, but it has and continues to work for certified aircraft so why re-invent the wheel?
~$16 at Spruce.

http://www.aircraftspruce.com/catalo...es/6070amp.php

I'm not a big fan of the ANL. While I will use fuses for other things, I would not use one on the alternator B lead. Also, I may be wrong but, I don't think any certified aircraft uses ANL.

[w1curtis]

Originally Posted by N941WR

..
Put an ANL fuse on the firewall. That way you won't have to run that big wire up to the panel and back.

Why would you need to run "that big wire up to the panel and back" if you are using a breaker?

[Mike S]

Originally Posted by w1curtis

Why would you need to run "that big wire up to the panel and back" if you are using a breaker?

Charge the battery.

As to using a pullable breaker for the alt output, somewhere in the deep dark recesses of my poor little brain I seem to remember reading that pulling the breaker on an alternator while it is putting out juice is not a good thing. The proper way to stop the output is to stop the field current.

That is why the "alt" switch is on the field, not the output----not to mention that the load rating of the switch can be a lot lower.