When servicing equipment & a bad fuse is found. I only have a limited amount of fuses to use to test the equipment. Glass fuses, i believe they are called buss fuses.

Is there a tool, such as a low amp mini breaker i can use instead of using up fuses.

 

You could use an amp meter to determine the load on the circuit with a good fuse in place. If the fuse blew because of a short you would use a multimeter to check continuity .

 

What application are we discussing...... old home fuse panels ?

 

Hi Fortis and welcome to the forum.
As Pj asked what is your application?
When working on circuit boards if I ran into a pico fuse or other direct wired fuse I would wire in a fuse holder so I could use the less expensive 1" glass fuses. Sounds like it is the glass fuses you want to avoid using up. If so, are they just in short supply or do they cost a lot.

Another approach would be the meter that pcboss described and a slow blow fuse. Typically they will give you a brief second to get an indication from an analog meter as to short or normal current. You can't leave it on in a short condition or smoke may point you to the bad component.

 

Remember the fuses car's used to use, the glass fuses. They are in microwave ovens & many types of equipment .

Heres my situation, let's use a microwave oven as an example. If i find a blown fuse & i think i might have found the issue. I then put in a new fuse but it blows. As a service tech i only have a limited amount of fuses in the van. So i'm forced not only to order fuses but i still don't know the issue with the equipment.

I'm trying to find a way to test the equipment without using a new fuse, i don't know if there is some type of low amp breaker i can use instead of using new fuses only to blow.

But, fuses have different amp ratings, so is there a mini, low amp breaker with adjustable amp ratings or some type of homemade device to avoid blowing new fuses.

 

It's not cost that's an issue, as a field service tech it's not good to order parts.I'm trying to ordering fuses.

 

They make automotive mini ckt breakers. You'd have to so some soldering to an old blow fuse, but that might work. The problem is automotive fuses are rated DC, are the situations you are talking about DC or AC?

BUSS is just a brand name. Littlefuse is another. Either of those sites should have size charts.

 

I mainly deal with AC, as 1 member mentioned a slow blow fuse. But, that would give me seconds to troubleshoot the equipment.

Companies supply techs with limited supplies. I might only have only 1 fuse for the equipment in question. If i use it & it blows i have to order another 1 & companies frown on this.It's not like i can buy a box of them for my personal use.

Lets say a member here is working for a company & they only have 1 fuse in the service vehicle. Ok, you are servicing equipment & when you arrive at the customer & find the fuse bad.

I don't want to use the only fuse i have in the service vehicle, i don't want to risk jumpimg the fuse holder with alligator clips since this might cause more issues.

I might take me quite some time to troubleshoot the equipment, i'm trying to find a way to run the equipment with something, other than a fuse to troubleshoot the equipment. That's why i was thinking that there might some type of mini, low amp breaker. But i don't know if this exists.

 

I'd suggest stopping by an electronic or electrical supply house. Or perusing some manufacturer sites. Of course the breakers exist...you can buy all sorts of things with mini ckt breakers incorporated into them, from table saws to garbage disposals to outlet taps to extension cords. You need to know voltage and current rating of the fuse you will be bypassing.

 

First, you can't troubleshoot a circuit with power and a short, so start with no power and your ohm meter. Factory testing often establishes expected ohm readings for a given good circuit board and you can do some of the same if you are dealing with the same boards over and over. Until you can get a good resistance reading don't apply power, that will save some fuses.

Over current protection seems like a hot topic when searched. I didn't read this entire link but "In this project I will show you how to create a simple circuit that can interrupt the current flow to a load when the adjusted current limit is reached." Seemed to be talking about something similar to what you are asking.
DIY Short Circuit (Overcurrent) Protection

Bud

 

For a service company to send a tech with only one fuse is ridiculous .

 

When troubleshooting short circuit issues in building/home wiring I will put an incandescent light bulb in series with the circuit to have enough resistance that the fuse/circuit breaker does not trip/blow. The handy thing about the light bulb is it will glow brightly while the short is present, but when it is eliminated the light goes out.

You could likely use the same concept in troubleshooting appliances. You might have to find the right bulb that works for your application.

 

The thing is there are many manufacturers, different types of equipment & many models from new to 20 years old. A tech would need 10 tractor trailers following him to have all parts needed. What the companies do is provide the techs with the basic parts & only parts that are used mostly. A certain part, in this case a fuse might not be used enough for the company to include in the van inventory.

 

And fuses are a pain as even with a dozen on hand you can still run out while trouble shooting.

One tool you might consider, since they have dropped dramatically in price, would be an infrared camera. When there is a short that takes out a fuse sometimes the offending component/s get hot. I bought my IR camera after retiring from the field service business but on the bench it sure would have avoided a few burnt fingers. That was the old way to find hot components.

Bud

PS, you might do some searching at "ThomasNet". That is the online version of the old Thomas Register that helped me many times.

 

The issue is that the customer calls for service & by the time the tech arrives it's many hours, or even days.