Replace Old Breakers?

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mkgrady

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If a circuit breaker is say 40 years old should it be replaced? This is a hypothetical question. Let’s stipulate that the breaker is in a good environment. No corrosive, damp or dusty atmosphere. If it should be replaced, what would be the reason? I ask because I see some are of the opinion that a 40 year old breaker should be replaced because of its age. I’m trying to figure out why.
 
I think you will get a mix of answers both for and against replacing them.

I'm 50 years old, maybe I should be replaced:blink:

Let me add this: the only real way to know if a breaker is good is through testing. For smaller framed breakers - like 400 amp or less and under 600 volts it cost more to perform proper testing then it cost to replace so that is why you see some that just replace after a certain time period.
 
Zog would perhaps be the most qualified person here to answer your question.

It seems to me that the type and manufacturer of the original breaker would have a lot to do with its suitability 40 years later.
 
Turn them off and on a few, 40, times to make up for the 40 years they were never exercised annually. How do they ‘feel’? Certainly a subjective decision and it doesn’t mean they won’t trip when needed. I wouldn’t replace them just because of age.

i am getting close to my second replacement if age is the only determining factor.
 
Had an I line breaker that is probably 40 years + old trip the other day, for a condition it should be expected to trip. But really no way to know before hand if it was functioning properly, nor is there any guarantee it will work again.
 
mkgrady said:
If a circuit breaker is say 40 years old should it be replaced?
...
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Disclaimer: Response is aimed at industrial process.
Assuming you meant 480V or less - and molded case:

One of my customers has a lot of 40+ year old MCCs and switchboards. It is pretty good gear and they keep up the maintenance. New CBs are not generally available. Replacing with a new style (new manufacture) is expensive.

They keep watch with thermography surveys. When one starts getting hot, they look at rebuilt if they can get one. If not, they spend the required ft^3 of money to get a listed replacement.

So, for this case - no.

I hear brainwaves from someone asking, "Why don't they put in new MCCs?"
They will, but it is expensive and a lot of down time.

the worm
 
kwired said:
.... But really no way to know before hand if it was functioning properly, nor is there any guarantee it will work again.
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See previous post disclaimer.

kw -
What you say is true. However also true of newer stuff.
I'm currently working a hidden failure on a current production electronic tip unit on a metal clad drawout.
Discovered during a 5 year PM. Trip contacts were stuck. Fixing it was easy - change the trip unit. I'm far more concerned with how many more of these they have - and how many fail the day after they were installed.

No, I have not yet had any flashes of brilliance.
 
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electricguy61 said:
I typically trust SquareD QO breakers from that era unless there’s a specific question about it’s operational status.

Wouldn’t say the same thing about a Waddsworth, Zinsco/Sylvania or a Federal Pacific.
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Let's see, my parent's house was built in 1961 and still has the original FPE panel in it...
 
kwired said:
Let me add this: the only real way to know if a breaker is good is through testing. For smaller framed breakers - like 400 amp or less and under 600 volts it cost more to perform proper testing then it cost to replace so that is why you see some that just replace after a certain time period.
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^^accurate

Molded case low voltage circuit breakers are typically tested to UL standard 489. UL uses the following test goals to determine if a breaker is considered to be safe (incompliance with their safety standard):
• The breaker must interrupt the maximum short circuit current two times.
• The breaker must protect itself and the connected conductor and the equipment it is installed in.
• After having been tested the breaker must be fully functional and pass a thermal calibration trip test at 250% of its rated ampacity; and pass a dielectric withstand test at two times its rated voltage or a minimum of 900 volts.
• The tested breaker must also operate properly and have continuity in all of its poles.

So how many times has that 50 year old breaker interrupted a fault?

Power breakers are a different story, they are designed to be rebuilt and sometimes upgraded and when properly maintained and overhauled per OEM recommendations can last forever. Half of this country's power probably runs through 50 year old GE Magneblast breakers, best breaker ever made IMHO.
 
iceworm said:
I hear brainwaves from someone asking, "Why don't they put in new MCCs?"
They will, but it is expensive and a lot of down time.

the worm
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We build direct replacement MCC buckets for older designs that use new components , easy swap out and only down time is time is takes to pull one bucket and slap in the new one.
 
iceworm said:
See previous post disclaimer.

kw -
What you say is true. However also true of newer stuff.
I'm currently working a hidden failure on a current production electronic tip unit on a metal clad drawout.
Discovered during a 5 year PM. Trip contacts were stuck. Fixing it was easy - change the trip unit. I'm far more concerned with how many more of these they have - and how many fail the day after they were installed.

No, I have not yet had any flashes of brilliance.
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True you don't really know if a brand new unit is good, not too many are interested in using fuses for everything though they are nearly guaranteed to always work on some level.
 
zog said:
We build direct replacement MCC buckets for older designs that use new components ....
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And I'm sure you do an excellent job. And they are listed - right?

This particular customer does buy listed, retro-fit buckets - current manufacture parts. I think AB makes them. Yes, they want listed. Yes, they are a bit expensive.

The worst are the bolted-in, wired direct to bus, larger CBs - MCC, not draw-outs, typically molded case above 200A (400A+ frames). Getting those listed is cubic money. Yes, they do all they can to get used, rebuilt when they have to replace one.
 
It seems like the age of a breaker has no bearing on its functionality. I think I’m reading here that exercising them would be a good thing.

I’m guessing no load exercising would be preferred.

Now I’m wondering if 20 years from now 60 year old breakers will still be reliable as compared to new.

Again this is assuming a clean dry atmosphere.
 
zog said:
Power breakers are a different story, they are designed to be rebuilt and sometimes upgraded and when properly maintained and overhauled per OEM recommendations can last forever. Half of this country's power probably runs through 50 year old GE Magneblast breakers, best breaker ever made IMHO.
Click to expand...

Does GE still make then today?
 
fwiw.. began my career in San Francisco with alot of aging infrastructure- i learned early that every time you operate a main of any kind, dont expect it to work when you throw it back on!

its a good idea to get the dust off of mcb's before operating it. i believe dust/dirt/drywall crap can get on the internals and possibly bridging the gap on the contacts...
 
iceworm said:
I'm currently working a hidden failure on a current production electronic tip unit on a metal clad drawout.
Discovered during a 5 year PM. Trip contacts were stuck. Fixing it was easy - change the trip unit. I'm far more concerned with how many more of these they have - and how many fail the day after they were installed.
Click to expand...

Interesting, I'm trying to think of a current production trip unit that still uses internal trip contacts? What type was it?
 
Interesting, I'm trying to think of a current production trip unit that still uses internal trip contacts? What type was it?
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These are not part of my client's equipment, however they are examples:
As I recall:
Micom (generation protection)
C-H Digitrip 1150 (+ and +i)

I think these two use contacts and are still in current production.
 
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