Resetting tripped circuit breaker

jonvcaples

jonvcaples

Pre-takeoff checklist
Gone West
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Just curious, how many times will you reset a tripped breaker while in flight? Scenario, below FL240 and you are not planning an approach requiring DME its breaker trips. No smoke, odor, or sign of failure or problem. You wait a few minutes, reset it and it trips immediately. Reset or leave tripped?
 
Your scenario: Not needing it. Trips twice, 2nd time being immediately - stays off. Especially with you saying the 2nd time was immediate.

There's an internal short somewhere, and repeatedly forcing it to be energized will create a bad, bad thing that'll find you wishing you were on the ground.
 
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jonvcaples said:
Just curious, how many times will you reset a tripped breaker while in flight? Scenario, below FL240 and you are not planning an approach requiring DME its breaker trips. No smoke, odor, or sign of failure or problem. You wait a few minutes, reset it and it trips immediately. Reset or leave tripped?
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Don’t reset.
 
One reset then leave it alone and decide if you can use something else for DME (albeit non-certified as such).
 
Anyone having a problem with Adobe? I can't open the attached file @Let'sgoflying! posted.
edit: by the way, my vote is reset 1 time
 
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During primary training I was taught one reset only, period. Doesn't matter which breaker it is either, one reset, if it pops again go without and get on the ground promptly.
 
Greg Bockelman said:
Tell me about it. I just learned that the hard way with a fuse on my truck.
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Yep. In desperation when the fuel pump fuse blew on my '93 Range Rover out in the middle of nowhere, I replaced it with a slightly higher rated fuse to get me out of the boonies. Made it closer to civilization.. but did some damage and made some bad smells in the process. Instead of just a new fuel pump, I got to replace part of the wiring harness, too. Goody. Never again.
 
Don’t reset the second time.

If it was something I didn’t need, I would not have reset it in the first place. Had my flaps breaker pop in the pattern. Leave good enough alone. Land. Diagnose with feet on terra firma. Only bad can happen by resetting, even if low risk.

Resist the urge to push the button in. It’s like those clear screen protectors on new equipment...can’t resist peeling it off...something satisfying about pushing a breaker in.

If it’s critical equipment? Make the call as PIC. Usually reset once.
 
I think I've seen reset-once-only in checklists.
 
I have had a radio fire without popping a breaker.

A breaker does no pop for fun, it is a fault in the wiring or devices, they do not fix themselves. Trouble shoot on the ground, with fire services really available.

Modern IFR equipped aircraft have enough redundancy to assure safe flight with any device out of service. That assumes that you are suitably up to date on your training and skills.
 
geezer said:
I have had a radio fire without popping a breaker.
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Me too - at night. My breaker didn't trip, but I sure pulled it fast. I never would reset a tripped breaker in my airplane in flight, even once. Nothing they power is that critical. Probably the most important one is for the flaps, but I can land without flaps just fine.
 
I don't reset a tripped CB. Resetting it once may enough to get a fire started. Best to troubleshoot on the ground.
 
Zero resets for me. I have sufficient backups in dual G5s, handheld radio (comm, VOR, ILS, external antenna), manual flaps, free-fall landing gear.
 
jonvcaples said:
Just curious, how many times will you reset a tripped breaker while in flight? Scenario, below FL240 and you are not planning an approach requiring DME its breaker trips. No smoke, odor, or sign of failure or problem. You wait a few minutes, reset it and it trips immediately. Reset or leave tripped?
Click to expand...

Key word in the linked PDF on breakers from the FAA - Essential. If having it off is going to make you crash, then try to reset it once. Otherwise you're taking a zero risk situation and turning it into a minimal risk situation.

However, i can think of nothing in the cockpit that involves keeping the spinney thing spinning, so what would really be essential for most of us that we don't probably have a backup for already?
 
The tripped breaker may have just saved your ass from a fire.
You have to think; do you really need to energize that circuit again?
 
Once on the critical, leave the others out.

Disaster Drill 2008 016.JPG On one of the routine certification flights between KGJT and CNY in a T210 I noticed the main gear hanging out of the wells. I alerted the pilot, we saw the breaker out, he began resetting it. After the second or third time I told him to stop and grabbed the POH and began pumping. When we got back to KGJT, the crowd was out to watch, I had been talking to a Bud on the ground. The tower had us fly low down the main runway to see if the gear was down and locked, observed by Bud and Bob on the ground. Low, slow, with gear hanging out, the pilot decided to bank hard to the north, right at the ascending terrain. I immediately protested that we were breaking every rule in the mountain pilots rulebook, He said the crowd needed a show. We landed safely, afterwards we found a short in the nosegear, I never flew with him again. He was later fired for attempting to start a King Air with all the plugs still in the engines.

I've seen the crash trucks out 3 times in my career, thanks to a guy upstairs, only once did we need them. The biggest takeaway was how distracted the pilots became. The(hopefully) last time, the guy told me "if this ever happens again, I hope your with me".

I was taught three things to do no matter what happens in an aircraft. #1 fly the airplane, #2 fly the airplane, and #3 fly the airplane.
 
Here's a twist on the question, and a more common scenario I think.

How do you feel about pulling a cb then re-engaging it, to reset something? (typically an electronic device.. maybe a hydraulic pump)

It hasn't tripped. You are choosing to de-energize a device temporarily.
If you are ok with it, how many times at once, or over 30 minutes?
 
Ravioli said:
Tin foil makes a good fuse, too. <- Dear Lord, don't let anyone take that seriously.
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There is no such thing as 'tinfoil" any more since w learned how to mill aluminum foil to one mil thick. HOWEVER, a gum wrapper will do as well :fingerwag:

Jim
 
Greg Bockelman said:
Why would you need to do it more than once? Same scenario as resetting one.
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Im asking b/c I’ve seen it done & did not understand why, or potential consequences. Can find nothing written about it.
It is different than the first scenario. In the first scenario, there was a fault that caused the cb to do it’s job; detect & trip.
Not so in the 2nd case.
 
Anybody who said "never reset", you may wish to consider this. Every now and again a queer electron decides to run the other way through the electrical system and creates a glitch. If the circuit breaker/fuse is close to its ratings, the glitch may overcurrent the circuit for a few milliseconds, which is enough to pop a breaker run near its limits. Reset once. If the breaker pops right away, no more. If it happens again in a half an hour or so, reset again and get a competent sparky mechanic that understand electrical systems to find the glitchy component when you get the sucker on the ground.

Jim
 
First off, if a device is not working, I don’t see how cycling a CB will help. And I don’t see how cycling it more than once will help either.

One and done.
 
I was taught a breaker should be rated at 150% of the max load.

In today's world, pulling and resetting a breaker, is done to reboot a software controlled device many times.

I do believe there is a finite number that can be put on the cycles of both a manual pull and reset, and an over current trip and reset.

My experience has been that the over current trip cycle seems to weaken the breaker more quickly.

I've found more failed breakers and systems caused by loose connections at the breakers, and continually preach to tighten every connection you see.

We need to put into perspective just how many wires and connections, and switches, and breakers, and relays, and connectors, and bulkhead feed thru's, etc... in these aircraft.

They're several decades old in many cases, and we are relying on all of this, with minimal inspections.

The most important components in older aircraft are the wiring harnesses in my opinion. I have not seen a program that outlines inspections like engines, landing gear, control cables, etc...

I always felt a bit more secure flying in the 441's with all new wiring, than the evaluation flights before we tore into them..
 
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