Breaker application

[Jim Dungar]

This is a basic 3 pole panel or din mount breaker, when in the OFF position I expect the terminals the switch is pointing towards to be de-energized.

If this is your thought process then expected to be suprised some day.

I have no problems with vertical mounting but hate to see a breaker mounted upside down. If ON/OFF looks like this:

This is against the NEC, UL and most manufacturers instructions.

 

[rsdoran]

I have been surprised quite a few times, alas still around.

My point is/was be aware. There are some guidelines offered by NEC, IEC, CEC, OH SAY CAN YOU SEE ANY BEDBUGS ON ME?

Just because all the C's or whoever say you can does not mean you should.

They need to quit trying to write law books and just state things the way they should be i.e. label one side input and the other output.

The real issue is that the engineers, electricians etc. al should get on the same page and ALWAYS use the same procedure(s)

Alas, there are engineers and others like you that read all those C's and decide "OH I can do this because they do not tell me I can not".

 

[ndzied1]

Back to the main question, some breakers, especially ones also capable of motor protection have phase loss tripps. In this case, it is necessary to loop one of the phases through two poles of the breaker or it will not reset becasue one of the phases is missing.

This is typical of the Moeller PKZM0 style breaker, also sold in the XT line from Cutler Hammer, also sold in the 140M Line from Allen Bradley.

 

[Jim Dungar]

Alas, there are engineers and others like you that read all those C's and decide "OH I can do this because they do not tell me I can not".

Are you accusing me of designing deliberately dangerous systems? Or are you saying that I have no regard for standard practices?

 

[rsdoran]

I am not accusing anyone of anything. The fact is that all too often people recite standards that state the minimum guidelines etc.

The fact is WE, the people that do this, need to get on the same page and do things in a consistent manner.

NOTE: norms picture shows L1 etc, L usually denotes LINE "voltage", have no idea why T is used tho. For me that designates the top or incoming point of the breaker. TO ME, it should designate the same to ALL.

ALAS, I am not dumb enough to think that everyone does though, because as I mentioned people will read the C's and decide "I can do this because the standards do not say I can not".

What is worse is that people that should be conforming to specific formats are the ones that point out that those standards etc. state it is not disallowed.

 

[allscott]

Chill Ron. If you reread post #16 you will see that he is agreeing with you and is posting a published standard as reference.

No one should assume anything. I see as many bottom fed main breakers as I see top ones. Simply because the PDC feeds in most of the plants I have worked in are embedded in concrete. It just makes sense to come up through the floor into the bottom of a breaker.

Whenever I have done this I label everything in site that says "bottom fed breaker, breaker reverse fed". Not because I have to because of some code but because it is right. I don't want an electrian at the end of a 12 hour shift making any assumptions.

And because I have seen enough of these installations not labeled I never assume which side of any breaker is the hot side.

Never underestimate the stupidity of those who have gone before you whether they have a piece of paper in hand or not.

 

[rsdoran]

What you are refering too is MAIN breakers that are fed from the bottom of the panel, do not agree with bottom feeding at all BUT that can easily be seen in most cases.

This discussion is more about panels with din rail etc style breakers that may be bottom fed WHEN it is not obvious.

IN these situations there may be several breakers involved with some being bottom fed while others are top fed.

Like I said, just makes things simple when people attempt to follow some form of guidelines.

 

[Jim Dungar]

Ron,

I sit on one of the standards committees for my company. I am very concern with following guidelines. However in-flexible guidelines and simplisitic panel layouts are often not compatible.

The device that Norm posted is not a circuit breaker as defined by UL1077 (usually DIN rail style) nor by UL489 (industrial/panel style). In the US this device is called a Motor Protector or Manual Starter (in Europe it is called a breaker), this is why it has the T terminals designation for motor leads.

 

[stasis]

The device that Norm posted is not a circuit breaker as defined by UL1077 (usually DIN rail style) nor by UL489 (industrial/panel style). In the US this device is called a Motor Protector or Manual Starter (in Europe it is called a breaker), this is why it has the T terminals designation for motor leads.

quite right, it's not a breaker. Main breakers that are mounted in panels (thru-door type) are commonly called lug-in/lug-out breakers. Din mount breakers are just that. The starter is NOT a breaker and should never be substituted for one. The NEC states that starters require overcurrent protection, whereas breakers are overcurrent protection.

to the OP, most use phases A & C to feed the primary...anyone remember the high leg of older 480 systems? This was always put in the B phase, hence using A & C.

Ron, I agree 110% that all sides of this industry need to have a meeting of the minds, take regional control from local munincipalities (why is 480V Brown, Purple, Yellow in San Antonio, as per city codes?), and institute/enforce a set of uniform standards that span the entire electrical industry!...wow, when put like that it sounds so, well, logical.

 

[leitmotif]

The Navy taught me
Black White Red
1 2 3
A B C
gives you clockwise rotation.

Also on DC Red was positive and black was negative.

Then they switch from white (on ungrounded 480 for shorepower) to blue.

Then I become a civilian and I learn about neutrals.
White (or gray) is the neutral

Then as time goes on I learn about wild legs
Orange is wild.

Then at Boeing in 90s I learn that
Brown Orange Yellow is 480 three phase
Black Red Blue is 240 3 phase.

Then when you get into an appliance say a washing machine Green is not necessarily the ground.

I am sure people wonder why I mumble this litany of colors at times.
I agree it sure would be nice to have a standard set of colors that don't conflict and give me cause for people to wonder about what little sanity I have left.

In my mind Brown Purple Yellow makes sense for 480, except that purple and brown (was it??) was used for 125 VDC at Trojan which was an utility who were a world by themselves.

Dan Bentler

 

[ndzied1]

quite right, it's not a breaker. Main breakers that are mounted in panels (thru-door type) are commonly called lug-in/lug-out breakers. Din mount breakers are just that. The starter is NOT a breaker and should never be substituted for one. The NEC states that starters require overcurrent protection, whereas breakers are overcurrent protection.

I'm pretty sure the device pictured is also rated as a UL489 Circuit Breaker. Not at work to look up the papaer work but I'll check later.