Old Fuses

[TexMedium]

Anyone Know anything on the subject? Specifically, the main panel in my house is a Federal Pacific Electric 200 amp, split buss panel. All fuses, NO circuit breakers, original to the house construction circa 1959. There are five two-pole breakers on the upper buss, all supplying 240volt loads. One of the blocks is big, holds 100amp fuses that feeds the lower buss, which holds 20 "Edison Base" single pole fuses. All of the upper buss fuses are old, again possibly original. There WAS an electric water heater fed by a pair of NON-30 Buss fuses. A couple of nights ago, the wife smelled what she has been calling "blue smoke", and went downstairs to find smoke and flame coming off the upper buss. She controlled it and stopped it, but it scared her spit-less. Anyway, the investigation into the cause showed that one, or both, of the elements in the water heater bridged and shorted, but only one of the fuses actually "blew". I could read zero ohms continuity on what was left of the melted down fuse block. These fuses, all of them, are either the one's that were in place when i bought the joint, or in a cigar box that was on a shelf next to the panel.

I've lived here sixteen years and have never bought any of these "cartridge type" fuses, so they are all at least that old. My best guess is that they might be much older. So, do these fuses "age out"? Should i be afraid of the one's still in place? Or, should i just replace them all with new? Replacing the panel right now isn't in the budget, time, or money.

 

[Bert_]

Usually fuses age very well. They are pretty simple and just work for the most part. Much better than circuit breakers which often have issues with age.

Did you check to see if the clips that hold the fuses are tight? That's the most common failure on those pull out fuse blocks.

 

[Mr_fixit]

Just my opinion, but the fuses would not change with age. But did the previous owner do some rigging with pennies or copper wire to bypass the fuse, maybe cause they kept blowing?

 

[TexMedium]

Yes the contacts have been checked, although i couldn't tell you exactly when i did it, i have done it. The elements in the water heater are shorted, clear and simple. The one fuse never opened, just kept passing current until it melted the bakelite housing. It still tests continuous! The consequences could have been MUCH, MUCH worse. And there was NO tampering or rigging done here. The previous owner was a widow woman who built the place with her husband. He had been passed away for quite some time. Any work down to the place before i got here would have been done by hired repairmen, and such. And i have been all over the panel. There was nothing out of place.

 

[Bert_]

It doesn't happen to be a renewable fuse does it?

 

[Norcal]

It doesn't happen to be a renewable fuse does it?

Interesting thought. Some manufacturers do recommend not using them due to overheating issues.

 

[Bert_]

Interesting thought. Some manufacturers do recommend not using them due to overheating issues.

I was wondering if it was a renewable with a couple wraps of copper wire inside.

Looks normal from the outside and lots of people don't know what a renewable is and that the end unscrews.

 

[Jim greengo]

Sounds like it's time for a service upgrade.

 

[Leaflessshadetree]

The one fuse never opened, just kept passing current until it melted the bakelite housing. It still tests continuous!

The first blown fuse opened the circuit at which point current stopped flowing through the other fuse.
A little smoke and a flash of light is normal when fuses blow, I've never seen flame.

 

[u2slow]

My house insurance with a fuse panel would either be impossible to procure, or insanely expensive. Weigh that against a service upgrade.

 

[Bert_]

I'll be honest,
If everything is in decent shape, there is enough circuits, and it's not over fused I wouldn't change it.

The insurance thing is getting to be an issue. Some are making a blanket requirement to upgrade. I've changed a few really nice fuse panels because of their insurance. Yet they ignore a lot of crappy breaker panels.

 

[Norcal]

Home inspectors would freak because it’s a FPE, but fusible panels are not the product that FPE has a bad reputation for.

 

[TexMedium]

Um, it was a wee bit more than some smoke and a flash. The eyewitness described flames. And they were Buss NON-30 fuses, NOT repairable, or tampered with, or modified in any way. It simple did not open and just kept passing current until it got hot enough to ignite and melt the fuse holder. Further, today i pulled all of the wire to the water heater, there is NO evidence of the wire being overheated anywhere on it's length, except the inch or two at the fuse holder.

As for my homeowner's insurance, well, they are pricks to start with, and will never pay any claim, ever. Weeks after moving in they tried to cancel the policy because i "failed to disclose" the home was in a flood plain, and "failed to disclose" previous flood damage. Seems there had been a tree root problem YEARS before i purchased the house, which had caused a sewer pipe failure and back-up into the basement. We are 50 feet elevation above the mean high water level of the nearest stream. And, the insurance agents father lives two doors away. Still, to this day they list me as a flood risk. Screw 'em.

 

[Norcal]

Time to find another insurance company, unless you live in a area where they are declining to write new policies, it's better to find a company that is a lesser A-hole. I live below the area where the Camp Fire occurred almost 3 years ago & insurance is a issue there.

 

[walta]

Let’s see some photos but my gut says if like you said the Bakelite was melted I think the panel done.

Lots of people will never find the money to replace the panel and put it off until they have no choice but to do it and I am thinking that is where you are now.

How well can you sleep knowing your family is in the house with that panel?

Walta

 

[Dagny]

smoke alarms?

 

[Solarphil]

All fuses (and breakers) have a trip curve - a large overcurrent event clears the element quickly, a low overcurrent can take some time. You want a certain amount of that to prevent nuisance trips. Likely when the element faulted, the one phase cleared pretty quick - btw I doubt the element shorted (a good element should measure continuity like a short, but of a known fixed resistance), but rather it corroded away until it cracked, at which point it starts acting more like an underwater arc welder. In theory on a 240v heater that should open the circuit and stop the little pixie dance. I suspect that somehow energy from the other phase continued to find a path to ground, perhaps helped through minerals and buildup in the tank, but the current level was not enough to clear the other fuse. However, whether due to level or duration, it clearly was enough to damage the fuse holder. That is one advantage of breakers over fuses, the poles are interlocked.

OP if replacement of the panel is impossible, I’d recommend close inspection of the fuse holder elements. If they are brittle, loose or otherwise damaged by the fault then I’d look at whether you can swap circuits around, are any of the other circuits not used or able to be sacrificed? If not, I’d consider bypassing the damaged fuse holder and installing a 2 pole breaker box immediately next to the existing panel, and serving the hot water heater from that.

 

[rburke65]

A FPE panel has always caused my eye brows to raise......

 

[Ado]

Took a course in the National Electrical Code years ago(It was the 1976 Code). Our instructor commented on fuses vs breakers. According to him(And he was the electrical inspector for the City of Grand Rapids, MI), a fuse is much more reliable, you can count on it to blow at the it's stated current flow with nearly 100% certainty. The people who manufacture circuit breakers will only guarantee that breaker will trip at it's stated level the 1st time it trips. Different current overloads can alter the amps it will trip at again after the first time it trips. Also he commented there are some spiders that are tiny enough to find a way into circuit breakers and spin a web in and around the trip mechanism. In his opinion, fuses can always be counted on to blow at their rated amps. Not so the breakers. But hey, this guy was an old timer. What did he know? He even said knob & tube wiring in walls is the safest wiring to have. The conductors are held away from combustible wood, etc., unlike Romex type wiring.

 

[u2slow]

@rburke65 I've yet to hear about home insurance screening/declining for FPE in Canada. It would be good to know if that has changed. Every 2nd home over 20yo seems to have FPE because it was the cheapest.

@Ado I agree that fuses are more reliable, but same thing with insurance calling the shot. Most companies (the agents anyway) don't even know their own particulars - like main fuses vs branch fuses.

 

[NUTTSGT]

Probably the biggest issue with fuses, in general, is people swapping out larger ones when smaller ones trip. Anybody will swap a fuse, buss style or screw in.

I'd guess 9 out of 10 people wouldn't open a breaker panel to swap a breaker

 

[PelicanPines]

Family owned a "State Inspected" apartment building in the 60's... had to put "limit" adapters in the majority of the fuse "sockets" that could NOT be unscrewed and stipulated the exact value of fuse allowed in that socket. I so wish I had pictures... Several of the panels were limited to 60amp TOTAL for all the fuses added together. (1 bedroom apartment)

 

[Dagny]

Your having a graduation party and have five roasters plugged in in your garage. Your ignorant you just keep turning the breaker back on. You are going to have a fire. Unless you are an electrician you probably only have a box or two of fuses so someone has to go to town for more fuses and it can cool down.

 

[u2slow]

Family owned a "State Inspected" apartment building in the 60's... had to put "limit" adapters in the majority of the fuse "sockets" that could NOT be unscrewed and stipulated the exact value of fuse allowed in that socket. I so wish I had pictures... Several of the panels were limited to 60amp TOTAL for all the fuses added together. (1 bedroom apartment)

Similar with a 70's vintage building I frequent. IIRC, they are called S-type rejection style fuses.

 

[engineer2]

My first house had a 1959-ish FPE breaker panel. During remodeling in 1994 I found some circuits would melt the wire before the breaker tripped. This was the early days of the Internet, but FPE hazard warnings were already posted. Into the trash it went.

 

[Two Speed]

Just throwing this in, I also have an old fuse panel. Had the stove lose a leg. Pull the cartridge fuses and start look up the specs, find the previous owner put in some sort of slow blow fuse (which shouldn't surprise me, every glass fuse had a slow-blo in it when I moved in, promptly replaced all of them with normal 15amp screw in fuses)
Do some spec digging on the fuses as something raised a red flag for me when looking online for a replacement fuse (If I remember right, it was something to do with resistive loads). Dug a bit on the fusetron (eaton) and bussman sites, coupled with local supplier got a proper fuse type--basically a normal blow fuse.. So ruminating, if somebody put an improper fuse type in there it may not have blown as quickly as you would expect.

 

[KenC]

. Further, today i pulled all of the wire to the water heater, there is NO evidence of the wire being overheated anywhere on it's length, except the inch or two at the fuse holder.

That sounds like the root cause may have been a high resistance connection at that point. That situation can create excessive heat without drawing enough current to blow the fuse (or a breaker). I've seen several examples due to oxidation, loose connection etc.

 

[TexMedium]

After much thinking about the evidence observed, i came to the same conclusion about a high resistance connection at the point of all of the damage. As such, i have pulled, and cleaned all of the other fuse holders. None showed any evidence of corrosion or "looseness". As for the water heater, i used two circuits on the Lower Buss, and wired them through a circuit breaker equipped disconnect at the tank, as suggested above. Two layers of protection, if you will. I sleep just fine.

 

[wyliesdiesels]

Anyone Know anything on the subject? Specifically, the main panel in my house is a Federal Pacific Electric 200 amp, split buss panel. All fuses, NO circuit breakers, original to the house construction circa 1959. There are five two-pole breakers on the upper buss, all supplying 240volt loads. One of the blocks is big, holds 100amp fuses that feeds the lower buss, which holds 20 "Edison Base" single pole fuses. All of the upper buss fuses are old, again possibly original. There WAS an electric water heater fed by a pair of NON-30 Buss fuses. A couple of nights ago, the wife smelled what she has been calling "blue smoke", and went downstairs to find smoke and flame coming off the upper buss. She controlled it and stopped it, but it scared her spit-less. Anyway, the investigation into the cause showed that one, or both, of the elements in the water heater bridged and shorted, but only one of the fuses actually "blew". I could read zero ohms continuity on what was left of the melted down fuse block. These fuses, all of them, are either the one's that were in place when i bought the joint, or in a cigar box that was on a shelf next to the panel.

I've lived here sixteen years and have never bought any of these "cartridge type" fuses, so they are all at least that old. My best guess is that they might be much older. So, do these fuses "age out"? Should i be afraid of the one's still in place? Or, should i just replace them all with new? Replacing the panel right now isn't in the budget, time, or money.

Yes the contacts have been checked, although i couldn't tell you exactly when i did it, i have done it. The elements in the water heater are shorted, clear and simple. The one fuse never opened, just kept passing current until it melted the bakelite housing. It still tests continuous! The consequences could have been MUCH, MUCH worse. And there was NO tampering or rigging done here. The previous owner was a widow woman who built the place with her husband. He had been passed away for quite some time. Any work down to the place before i got here would have been done by hired repairmen, and such. And i have been all over the panel. There was nothing out of place.

So the elements shorted to the grounded tank? If so, then thats the reason the second fuse didnt blow. Its because it was operating @ 120v which means the current draw was lower.

The first blown fuse opened the circuit at which point current stopped flowing through the other fuse.
A little smoke and a flash of light is normal when fuses blow, I've never seen flame.

not if the element was shorted to ground.

 

[nadogail]

IMHO, All FPE and Zinsco panels and their associated circuit breakers belong in the landfill.