Technical Electrical: circuit breaker works in place of inline fuse?

Am in the middle of rewiring the path from my electric fuel pump, isolating it away from the main fuse box, calls for a 30A inline fuse between the relay and battery. Found a new 30A circuit breaker forgot I'd had, could save me a trip to the store.
Will this inline breaker work in it's place?

 

Yes it will work just fine,it does what it is,it will reset after cooling off,if it kicks off again you have a short

 

In theory it seems like it should work OK. But for automotive use it seems like circuit breakers are mainly used in higher amp draw circuits with short term usage. Things like power windows and power seat adjusters. Unfortunately I don't know why this is, and it may just be a coincidence.

Provided that the breaker is working properly I don't see any harm in trying it. Maybe the breakers are more or less sensitive to current spikes. Don't know if fuel pumps are prone to those issues, maybe a current spike when first turned on that trips a breaker?

At work I see customers wanting to replace circuit breakers ***uming that they are the reason their power windows quit working. I'm sure that the breaker can fail, but I doubt that they ever consider that there's maybe something wrong in the circuit that's creating a high amp load which is causing the breaker to do its job.

 

Only drawback to breakers is in a high resistance short. They will continue to reset and trip, so each time you have the chance of igniting the insulation unless the wire melts in half. I'm not a breaker fan. I'd rather have a fuse blow and keep the circuit open until I can find the short.

 

1971BB427 sounds the most sensible and safe. Use an in line fuse.
Isn't 30 AMPS kind of high. I use a 15 amp for my electric fuel pump.
What's the data on the pump say?

 

each time it heats up & trips it is weaker trips easier

 

Why not just go hey an inline atc fuse holder and fuse.

 

Most hi performance electric fuel pumps draw about 3 amps contiuous, and even with inrush currents they wont go over maybe 7 amps. I always use a relay, and a 20 amp fused circuit across the contacts to feed the pump, with #12 wire. (rated 20-25a depending on insulation)

 

?Que?

 

Thanks for the feedback. Got it all hooked up, Fuel Pump grounded to frame and connected to Relay, Relay branches out to battery (with CB, replace with fatty fuse tomorrow) as well as floor-mounted toggle, grounded to frame.
Nothin yet, trying to recall where/what prong two of the toggle should go to... ground, I think....

 

Fuel Pump power line used to go to fuse box (fuse-tapped), but disconnected that from the box, connected it to relay...

 

I'll get an inline fuse this week, just broke-Sunday and wanted to get the main setup up, for today...

 

There are a lot of cars that also have CB in the wiper circuit. Nothing wrong with using a breaker in the FP circuit, it might just get you safely off the side of the road some time not having to stand along the freeway to replace a blown fuse. (I feel this is the reason behind CB in wiper and HL circuits). The reasoning behind CB in power seat and window circuit is there is no "stop" built in and if someone sits there holding the ****on too long the motor could burn out.

 

Fuel pump switch should be fed from a smaller 1-2a fused control circuit. Then to a switch and out of the switch to the coil of the relay. The other side of the relay's coil should be grounded. The power fuse (suggested 20a.) should go to one side of the contacts, and the other side to your fuel pump. The other side of the pump lead to ground.

 

That's how I have it set up, except I'm missing a connection to one of the toggle's two prongs. Trying to avoid fuse-tapping it back into the fuse box (unless the short from before would now be prevented by the inline relay system).

 

i first came accross relays rewireing my 77 xlch.i didnt trust them at first.but when the headlight circuit tripped out one evening in the middle of nowhere i soon spotted the problem and was able to make it home with lights.i didnt have a pocket full of fuses.once the relay reset i was good to go.a great invention

at a later date i had a circuit breaker fail but that was on a 75 flh stroker thatwas over 35 years old at the time

 

Headlight relay is actually next on my list....

 

over here available from your local harley dealer at inflated pricrs

 

subscribed?

 

to the thread

 

Oh hell, Tim, just do it the Eureka/Arcata "Tweeker " way, and wire that ****er direct...figure 14 gauge wire will melt at about 35 amps anyway, so there ya go... 8=)
(just kidding, HAMB-ers, just kidding)
I guess I missed the antique drags at Samoa, huh? and don't forget, Sea Cruise is coming up fast, been out in the garage during this rain storm with the radio on, workin' on the '26 and the '57...

 

DAVE! yes, you did. When is the Sea Cruise? Rain here, too, trying to wrap up this under-the-truck stuff soon... my duplex garage leaks ground water from the retaining wall, like the Blob, slowwly advancing its stream towards my work area, gotta get back to it...

 

I think your response answers my question but that diagram seems to be lacking something. Somewhere in that "red wire" circuit there should be another fuse for the fuel pump, correct? Would it make any difference which side of the relay the fuse was installed on?

 

The wire on the 86 terminal in drawing has a draw of 150 to 200 milliamps, triggers the relay only.

 

Here ya go, Tim:


http://www.northernknights.us/Sea_Cruise.php

Hope to see you there, the friday night before is Cruisin' Hiway 101, unless you get really stupid, the local gendarmes tend to look the other way...