what is the proper name for switching breakers

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charlie b

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I tried to specify a similar item as the main on what I intended to be essentially an MLO lighting panel. I had a 100 amp cable tap riser fed via a 100 amp breaker, with a 100 amp panel on every other floor. I didn't need a main breaker on each panel, but I wanted some way to turn off the panel locally, without having to take out the entire riser. So I called for a "main switch," describing it as essentially a main breaker, but with the overcurrent "guts" removed. The panel manufacturer's representative said they could do that, but they took credit for the overcurrent aspects of the main breaker as part of their panel's fault current rating. So I couldn't get the fault rating I wanted, without either going with a main breaker, or using a standard MLO panel. I wound up deleting the "main switch" requirement, using a MLO panel, and putting a non-fused disconnect switch upstream, to allow for local isolation. Live and learn. :roll::D
 

kwired

Electron manager
Location
NE Nebraska
What I could not believe is UL allowed these to be made, without some kind of way to prevent them from being used in a regular breaker panel, like the CTL tandem breakers.

Ignorant or untrained people will find a way to use something wrong anyway. Have you never seen a piece of copper pipe in place of a cartridge fuse? What is to stop someone from placing a 125 amp breaker on a 15 amp circuit if that is their solution to whatever problem they have? There is overcurrent protection but just about to the point that there may as well not be.

I tried to specify a similar item as the main on what I intended to be essentially an MLO lighting panel. I had a 100 amp cable tap riser fed via a 100 amp breaker, with a 100 amp panel on every other floor. I didn't need a main breaker on each panel, but I wanted some way to turn off the panel locally, without having to take out the entire riser. So I called for a "main switch," describing it as essentially a main breaker, but with the overcurrent "guts" removed. The panel manufacturer's representative said they could do that, but they took credit for the overcurrent aspects of the main breaker as part of their panel's fault current rating. So I couldn't get the fault rating I wanted, without either going with a main breaker, or using a standard MLO panel. I wound up deleting the "main switch" requirement, using a MLO panel, and putting a non-fused disconnect switch upstream, to allow for local isolation. Live and learn. :roll::D

Unless part of a big order for a project, if you wanted just an individual molded case switch they often cost more than a circuit breaker, not because of what is in them - the breaker should cost more, but because of the higer manufacturing quantities, and higher inventories of most popular sized breakers. Like why 4 foot fluorescent tubes are cheaper than 2 foot tubes.
 

stjohnbarleycorn

Senior Member
Have you never seen a piece of copper pipe in place of a cartridge fuse?

Yes i have and and was shocked, I asked the local inspector about it in the mid 80's , he said that that manufacture actually used copper pipe or something that looks a lot like a piece of pipe to make it an unfused disconnect, I thought I had really found something to tell him about, but the wind went out of my sails pretty quickly. ;)
 

kwired

Electron manager
Location
NE Nebraska
I have in corner-grounded systems, but I know that's not what you mean.

Once had a farmer tell me about how he moved the non fused link in the service disconnect of his corner ground supplied irrigation service because he was tired of changing blowing fuses on one of the other lines. He said it did not take long and there was fire on one of the transformers - pole top transformers. He thought he better put the fuses back the way they were before calling POCO. Long time ago I don't even remember what his real problem was. I was fairly new to the trade, and remember that farmers story still and after seeing a lot of things that I have seen on farms it is suprising we don't have more serious accidents than we do.
 

76nemo

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Location
Ogdensburg, NY
Kevin,

The commodity 15 Amp and 20 Amp single pole circuit breaker, in most all of the manufacturers models, has the rating "SWD", meaning that it is listed for switching duty.

Is the SWD rating what you might be asking for?

I have, on occasion, installed AC disconnects, like the one in the spec sheet that McGraw just posted, that has a non-overcurrent protective device (NOCPD) switch that looks like a breaker when the cover is on. I've never seen this NOCPD loose, without an enclosure.


Did this thread get jacked, or did Al not answer the OP's question here????
 

jmellc

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Location
Durham, NC
Occupation
Facility Maintenance Tech. Licensed Electrician
I haven't seen as much of them in recent years but I know they are still around. We use to call them dummy breakers. Used them a lot in outside HVAC disconnects where OCP was not needed, but just a way to turn on and off. Now, most people around here use NF pullouts if OCP is not needed.

Switching duty breakers (SWD), on the other hand, are rated for regular use as a switch and also provide OCP. I've mostly seen this situation in warehouses or other such buildings. A few night lights are always on, maybe a few switched ones, but most are turned on each day by the breakers and off by the breakers at night. No other switches. I use to hear that some office buildings in past years had few if any switches, and lights were left on all the time. That was when power was dirt cheap.

Yea, it would be good if dummy breakers would not fit panels, but, as others have said, uninformed people also install wrong breaker sizes and fuses, so it's not a perfect world.
 

big john

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Location
Portland, ME
I'm thinking you're looking for a molded-case switch. It looks just like a breaker, has interrupting ratings, but won't provide any over-current protection.

-John
 

76nemo

Senior Member
Location
Ogdensburg, NY
I'm thinking you're looking for a molded-case switch. It looks just like a breaker, has interrupting ratings, but won't provide any over-current protection.

-John



It's a breaker listed for switching purposes, "SWD".

Any branch circuitry must have OCPD, which with these types of breakers, they do, but they are listed for switching/disconnect.
 

Jraef

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Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
Once had a farmer tell me about how he moved the non fused link in the service disconnect of his corner ground supplied irrigation service because he was tired of changing blowing fuses on one of the other lines. He said it did not take long and there was fire on one of the transformers - pole top transformers. He thought he better put the fuses back the way they were before calling POCO. Long time ago I don't even remember what his real problem was. I was fairly new to the trade, and remember that farmers story still and after seeing a lot of things that I have seen on farms it is suprising we don't have more serious accidents than we do.
For years during the 1980's, there were a group of State Inspectors in the Columbia Basin (eastern Washington and Oregon) who would not approve any irrigation Pump Panels with fused disconnects for this very reason. Anyone who argued got a full blown lecture complete with a photo album of all the disasters caused by farm workers putting pieces of copper pipe or EMT in place of fuses.
 

Jraef

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Re: Molded Case Switches

Re: Molded Case Switches

Every breaker mfr offers Molded Case Switches, a.k.a Non-Automatic Circuit Breakers, they have their place. I often use them in control panels with thru-door operators as a nice compact disconnect switch. But they generally cost more than a Safety Switch or rotary disconnect so I have to really need the small size to be worth it. Generally, you can get them for the same price as the full breaker, or really "no extra charge to eliminate the trip mechanism". So there is no real advantage to using them in a load center or panel board unless you have a specific desire to cheat, i.e. fix a nuisance tripping problem by making the symptoms go away.

You can't legislate common sense.
 

hurk27

Senior Member
Every breaker mfr offers Molded Case Switches, a.k.a Non-Automatic Circuit Breakers, they have their place. I often use them in control panels with thru-door operators as a nice compact disconnect switch. But they generally cost more than a Safety Switch or rotary disconnect so I have to really need the small size to be worth it. Generally, you can get them for the same price as the full breaker, or really "no extra charge to eliminate the trip mechanism". So there is no real advantage to using them in a load center or panel board unless you have a specific desire to cheat, i.e. fix a nuisance tripping problem by making the symptoms go away.

You can't legislate common sense.

If you go to post 6 click on the link, then scroll down to page 4 in the PDF I can get those 60 amp rated 200TDR's all day long at around $15.00, just throw away the housing, mount the buss inside your panel, and there you go.:D
 
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