Where can you find/purchase a corner grounded delta (B phase) Din rail mounted 240V

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JNjie

Member
Location
United States
I am trying to find a circuit breaker for motor protection. The circuit breaker I am trying to find has the following specifications:

Must be Din rail mounted
-Provides Short Circuit Protection for a motor
-Doesn’t have to be Overload
-Has to be rated 240V,3 phase grounded, 20 hp
-Breaker has to be rated 1 phase- 3 phase suitability
-Must be corner- grounded delta (grounded B Phase).

I tried looking it up but it's hard to come across these breakers since they are rarely used anymore. Any suggestions on places to look ?
 

jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
PE (Retired) - Power Systems
I am trying to find a circuit breaker for motor protection. The circuit breaker I am trying to find has the following specifications:

Must be Din rail mounted
-Provides Short Circuit Protection for a motor
-Doesn’t have to be Overload
-Has to be rated 240V,3 phase grounded, 20 hp
-Breaker has to be rated 1 phase- 3 phase suitability
-Must be corner- grounded delta (grounded B Phase).

I tried looking it up but it's hard to come across these breakers since they are rarely used anymore. Any suggestions on places to look ?

The problem is the 20HP rating. It seems that most vendors jump up to 3pole devices above 30A.
 

Smart $

Esteemed Member
Location
Ohio
Would the NEC allow to use a 3 Pole with the specifications given?
I know the NEC permits three pole overcurrent devices as long as all poles are common trip. Never had reason to look at motor SC/GF as being any different.
 

Jraef

Moderator, OTD
Staff member
Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
I am trying to find a circuit breaker for motor protection. The circuit breaker I am trying to find has the following specifications:

Must be Din rail mounted
-Provides Short Circuit Protection for a motor
-Doesn’t have to be Overload
-Has to be rated 240V,3 phase grounded, 20 hp
-Breaker has to be rated 1 phase- 3 phase suitability

-Must be corner- grounded delta (grounded B Phase).

I tried looking it up but it's hard to come across these breakers since they are rarely used anymore. Any suggestions on places to look ?
The bolded lines seem confusing to me. Do you want a 2 pole breaker that goes on the B phase (+A or C), or do you want a 3 pole breaker?

You might be looking for something in the specs that you are not finding, because you are over thinking this. If you want a 2 pole breaker, it just needs to have a common trip, which would be as opposed to 2 single pole breakers. If you want a 3 pole breaker, there is nothing special about it. Just get a 3 pole 240V rated breaker that had a DIN rail clip on it. Pretty much everyone sells them, some you might have to use an adapter plate.

Either way, make sure you truly understand the available fault current in your system. Some of the extremely cheap little IEC style DIN rail breakers have very low ratings, as in 5kA if you are not careful. Also, make sure you understand the difference between UL1077 and UL489 listed breakers, that can get you in trouble too.
 

JNjie

Member
Location
United States
The bolded lines seem confusing to me. Do you want a 2 pole breaker that goes on the B phase (+A or C), or do you want a 3 pole breaker?

You might be looking for something in the specs that you are not finding, because you are over thinking this. If you want a 2 pole breaker, it just needs to have a common trip, which would be as opposed to 2 single pole breakers. If you want a 3 pole breaker, there is nothing special about it. Just get a 3 pole 240V rated breaker that had a DIN rail clip on it. Pretty much everyone sells them, some you might have to use an adapter plate.

Either way, make sure you truly understand the available fault current in your system. Some of the extremely cheap little IEC style DIN rail breakers have very low ratings, as in 5kA if you are not careful. Also, make sure you understand the difference between UL1077 and UL489 listed breakers, that can get you in trouble too.

A two pole or 3 pole , The breaker I want is for short circuit , the VFDs being used have a thermal lag already. I just need it to be din rail , 240VDC , 20hp , 100 A and can be corner grounded B-phase. A problem I have is getting to the UL 489 , does it state that a 3 pole or 2 pole can be used for B phase corner grounded?.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
A two pole or 3 pole , The breaker I want is for short circuit , the VFDs being used have a thermal lag already. I just need it to be din rail , 240VDC , 20hp , 100 A and can be corner grounded B-phase. A problem I have is getting to the UL 489 , does it state that a 3 pole or 2 pole can be used for B phase corner grounded?.

Nothing says you have to use all three poles, although I probably would just get a 3 pole CB and be done with it.

UL489 only cares about the maximum voltage line to line or line to ground. If the CB is suitable for ungrounded 240V 3 phase delta, it is suitable for 3 phase delta corner grounded.
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
Your concern would be if you got a slash rated (i.e. 240/120V) DIN rail breaker.
In a four wire 208Y120 system you could use a breaker rated for 240V line to line but only a maximum of 120V line to ground.
But in a corner grounded 240 delta you would need a full rated breaker instead because you have 240V line to ground.
You just need to be concerned that breaker you get is fully rated for 240V.
 

JNjie

Member
Location
United States
Ok thank you. Is there anywhere that states the 240V 3 OR 2 pole will be suitable for corner grounding delta? I just need a back up in case I have to show it is.
 

jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
PE (Retired) - Power Systems
Ok thank you. Is there anywhere that states the 240V 3 OR 2 pole will be suitable for corner grounding delta? I just need a back up in case I have to show it is.

Corner grounding is a special UL issue for 2-pole breakers.

Other than a Square D QOU3100, I am not aware of any other 100A DIN rail mounted breaker, although I am sure there most be one.

Why do you want DIN rail mounting? There are lots of breakers with line and load side lugs that mount to backpanels.
 

kwired

Electron manager
Location
NE Nebraska
Corner grounding is a special UL issue for 2-pole breakers.

Other than a Square D QOU3100, I am not aware of any other 100A DIN rail mounted breaker, although I am sure there most be one.

Why do you want DIN rail mounting? There are lots of breakers with line and load side lugs that mount to backpanels.
There are many other din rail mount type breakers out there outside of the big 4 panelboard maker's (Schnieder, Eaton, Siemens, GE) mainstream series - I think OP is looking into some of those for his application.
 

JNjie

Member
Location
United States
Corner grounding is a special UL issue for 2-pole breakers.

Other than a Square D QOU3100, I am not aware of any other 100A DIN rail mounted breaker, although I am sure there most be one.

Why do you want DIN rail mounting? There are lots of breakers with line and load side lugs that mount to backpanels.

The application I am using it for requires din rail mounted plus its easier when it comes to installing the circuit breakers.
 

JNjie

Member
Location
United States
Thank you everyone for the replies. I found a Square D breaker (HDL36100) from Schneider electric that has been tested for use on corner grounded delta systems and is UL listed. It is panel mounted but they also have a din rail kit you can use for it.
 

kwired

Electron manager
Location
NE Nebraska
Thank you everyone for the replies. I found a Square D breaker (HDL36100) from Schneider electric that has been tested for use on corner grounded delta systems and is UL listed. It is panel mounted but they also have a din rail kit you can use for it.
As should be the QOU3100 Don mentioned. The one you mentioned from what I know of their catalog numbers that is a 600 volt rated breaker - though one may need to consider other factors such as interrupt rating needed as well. The QO breaker is likely less cost if it will work - but that depends on your purchasing status with your supplier as well, depending on how sales accounts are set up seems to make a big difference on what you pay for Square D products, or which products you get a better price for.
 

JNjie

Member
Location
United States
As should be the QOU3100 Don mentioned. The one you mentioned from what I know of their catalog numbers that is a 600 volt rated breaker - though one may need to consider other factors such as interrupt rating needed as well. The QO breaker is likely less cost if it will work - but that depends on your purchasing status with your supplier as well, depending on how sales accounts are set up seems to make a big difference on what you pay for Square D products, or which products you get a better price for.
You are right , I am currently talking to a Square D vendor to verify if the breaker QOU3100 can be used for the application I want .
 

JNjie

Member
Location
United States
As should be the QOU3100 Don mentioned. The one you mentioned from what I know of their catalog numbers that is a 600 volt rated breaker - though one may need to consider other factors such as interrupt rating needed as well. The QO breaker is likely less cost if it will work - but that depends on your purchasing status with your supplier as well, depending on how sales accounts are set up seems to make a big difference on what you pay for Square D products, or which products you get a better price for.

The QOU3100 seems to be for regular panel-board. Also goes for the HDL26100 .I am actually looking for a 240 Vac breaker for an industrial control panel that can be din rail mounted and be corner ground. Its a custom design situation. These two square d breakers are for panel boards and wouldn't work for the application I would be using them for. NEC Article 409 is what i'm going by.
 

jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
PE (Retired) - Power Systems
The QOU3100 seems to be for regular panel-board. Also goes for the HDL26100 .I am actually looking for a 240 Vac breaker for an industrial control panel that can be din rail mounted and be corner ground. Its a custom design situation. These two square d breakers are for panel boards and wouldn't work for the application I would be using them for. NEC Article 409 is what i'm going by.

The QOU breaker is designed with integral DIN mounting.
Neither of these breakers is designed for plugging onto panelboard bussing, both are built with line side and load side lugs and are intended to be mounted to something like the back panel in an equipment enclosure. They are both UL 489 listed and so cane be used to meet the requirements of Article 409.
 

kwired

Electron manager
Location
NE Nebraska
The QOU3100 seems to be for regular panel-board. Also goes for the HDL26100 .I am actually looking for a 240 Vac breaker for an industrial control panel that can be din rail mounted and be corner ground. Its a custom design situation. These two square d breakers are for panel boards and wouldn't work for the application I would be using them for. NEC Article 409 is what i'm going by.

It is a QO frame, but the "U" in the catalog number denotes that it has lugs on both ends and doesn't plug/bolt onto a panelboard bus.
 
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