Fused Disconnect vs. Enclosed Circuit Breaker

[jap]

If you had your choice which would you choose for a service disconnect.
I used to be a pro breaker guy but as cheaply as things are being made anymore the Fused Disconnects seem to have sustained their robust integrity.
There are pros and cons to both.

If price wasn't an issue, I'm talking 400 amps or less, which would you choose?


JAP>

 

[augie47]

If total cost (material & labor) was not a factor, I would recommend fusible for the reason you stated. I have seen far more breakers needing replacing than I have fusible disconnects.

 

[ron]

I hate when the main fuse blow and there is no replacement available.

I also hate it when a 3 phase service has one phase blow, and down stream 3 phase motors that may not have phase loss detection get damaged.

I like breakers, although for high fault current applications (>65kA), fuses are a better option

 

[Carultch]

I also hate it when a 3 phase service has one phase blow, and down stream 3 phase motors that may not have phase loss detection get damaged.

I've always wondered why a set of fuses is acceptable as a general purpose OCPD in a 2 or 3 pole application, for precisely this reason.

 

[petersonra]

Modern circuit breakers are every bit as reliable as fuses and disconnect switches if they are properly maintained. In general, they are also more cost-effective above about 200 amps most of the time at least in my experience. Most of our customers make us include a spare set of fuses if they're over 60 amps and big fuses can get real pricey real quick.

 

[jap]

Modern circuit breakers are every bit as reliable as fuses and disconnect switches if they are properly maintained. In general, they are also more cost-effective above about 200 amps most of the time at least in my experience. Most of our customers make us include a spare set of fuses if they're over 60 amps and big fuses can get real pricey real quick.

What maintenance procedures are performed on a breaker?

JAP>

 

[iwire]

What maintenance procedures are performed on a breaker?

JAP>

Should be done or are done?

In most places no upkeep is done.

 

[petersonra]

What maintenance procedures are performed on a breaker?

JAP>

most big breakers you are supposed to do some kind of testing on now and then. if they are kept in a clean area, you can probably get by with not doing much of anything for the life of the product. I don't know anyone that actually does any testing of them.

I think you should operate them once a year or so just to make sure you still can, but really they are pretty reliable.

For the most part, the instructions I have seen basically seem to suggest vacuuming the dust off of them and a visual inspection being about all that is necessary for the typical person to do. That's probably all I would do unless there was some reason to do something different or it was a large breaker. Anything much beyond cleaning and a visual inspection requires equipment most of us don't have.

 

[jap]

Should be done or are done?

In most places no upkeep is done.

On a breaker type service disconnect that usually stems from the fear of when you turn it off it wont latch back on.
I think everyone breathes a sigh of relief every time they have to shut a main off and when they go to turn it back on it actually does.


JAP>

 

[iwire]

On a breaker type service disconnect that usually stems from the fear of when you turn it off it wont latch back on.
I think everyone breathes a sigh of relief every time they have to shut a main off and when they go to turn it back on it actually does.


JAP>

Been there too many times, that awful feeling of the breaker not latching on and jumping to the tripped position.

But that problem is a direct result of not turning the breakers on and off per the manufacturers maintenance recommendations. The grease sets up and gets more like paste than grease.

 

[jap]

Been there too many times, that awful feeling of the breaker not latching on and jumping to the tripped position.

But that problem is a direct result of not turning the breakers on and off per the manufacturers maintenance recommendations. The grease sets up and gets more like paste than grease.

But you got to admit it makes you feel like a hero when you beat on it all the way around with a rubber mallet for a while and it sometimes magically resets.
That along with a blade on a disconnect breaking off in the stabs makes the choice between the 2 a tough one.

JAP>

 

[iwire]

But you got to admit it makes you feel like a hero when you beat on it all the way around with a rubber mallet for a while and it sometimes magically resets.

I have no idea what you are taking about, I would never go gorilla on a large breaker that had to turn on or food would go bad. :angel: