Tandem-breakers installation

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  #1  
Old 08-31-16, 07:11 PM
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Tandem-breakers installation

Looking at the main panel in my house I noticed that tandem-breakers are installed in the slots where (if I understand the picture on the door correctly) only ‘regular’ breakers are allowed.


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Should I consider replacing breakers in the designated 'single' slots?

What is the reason for the manufacturer to not allow tandem-breakers in specific slots?
 
  #2  
Old 09-01-16, 03:51 AM
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Looks like spots 2 and 5 only accept single breakers, not tandems. The panel may be too full so tandems were installed for the additional two circuits. The tandems should be removed by code. A sub panel can be installed for additional breaker space.

The panel needs to be used the way the manufacturer states and listed the panel.
 

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Old 09-01-16, 07:50 AM
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Thanks a lot for the answer!

I guess, the simplest option to ‘fix’ would be to put a ‘Triplex’ breaker instead of the existing double-pole circuit (i.e. two outer 15 Amp single-pole and one Inner that matches the existing double-pole-circuit) to free up extra slots.

Now I have 2 related questions:

- The panel says, it supports Murray Style MP & EP breakers. It looks like MP-T are single breakers and compatible Murray duplex circuit breakers that are “1 inch wide and consist of (2) 1-pole breakers, in varying combinations” are rather of type MH-T – could you please advise?

- When I look at what is actually installed in the panned, I also see the ‘Cutler-Hammer DNPL’ type breakers. Those breakers are (obviously) physically compatible and are there for years, but not listed on panel. Is this acceptable?
 
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Old 09-01-16, 11:35 AM
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I guess, the simplest option to ‘fix’ would be to put a ‘Triplex’ breaker instead of the existing double-pole circuit
You can relocate some 1" double pole breakers and move tandems to that location as well.

ie. Move 3rd right double pole to top and move top 2 tandems down to where double pole used to be.
Move green double pole on left to bottom and move blue tandem to where double pole used to be.

The panel says, it supports Murray Style MP & EP breakers. It looks like MP-T are single breakers and compatible Murray duplex circuit breakers that are “1 inch wide and consist of (2) 1-pole breakers, in varying combinations” are rather of type MH-T – could you please advise?
MH-T is tandem breakers and should be compatible.

I also see the ‘Cutler-Hammer DNPL’ type breakers. Those breakers are (obviously) physically compatible and are there for years, but not listed on panel. Is this acceptable?
Only breakers "UL Classified" to be compatible to the panel are allowed. Cuttler hammber breakers you have are not.

Eaton UL Classified breakers (type CL) are compatible and as far as I know they are the only manufacture with UL Classified breakers.
I don't think they have any tandem breakers in that line.
 
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Old 09-01-16, 12:13 PM
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You can relocate some 1" double pole breakers and move tandems to that location as well.
Thanks for the great idea - I hope it works/wires will be long enough to move existing breakers two slots down

Only breakers "UL Classified" to be compatible to the panel are allowed. Cuttler hammber breakers you have are not.
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Some of the breakers already installed are Cuttler- Hammer breakers. Would you recommend to replace by Murray MH-T type?
 
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Old 09-01-16, 12:31 PM
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Some of the breakers already installed are Cuttler- Hammer breakers. Would you recommend to replace by Murray MH-T type?
They work fine in most occasion, but would feel safer by replacing with correct type.
At least check if they clip to the tab tightly.

Insurance may not cover electrical fire if it was caused by the wrong breaker.
 
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Old 09-02-16, 05:00 PM
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When I look at what is actually installed in the panned, I also see the ‘Cutler-Hammer DNPL’ type breakers. Those breakers are (obviously) physically compatible and are there for years, but not listed on panel.
That looks like an old Arrow-Hart Murray panel, I haven't seen one in years. Check that label in the panel again and look to see if the label doesn't list Bryant BR breakers as acceptable, I believe it should, but you check. If so, the Eaton/Cutler-Hammer BR series breakers can be used.
 
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Old 09-02-16, 05:57 PM
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CJ, the panel label says Arrow-Hart.
 
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Old 09-03-16, 11:24 AM
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That looks like an old Arrow-Hart Murray panel, I haven't seen one in years. Check that label in the panel again and look to see if the label doesn't list Bryant BR breakers as acceptable, I believe it should, but you check. If so, the Eaton/Cutler-Hammer BR series breakers can be used.
I think you are right - the are 3 types of the breakers I can see:
- Murray
- Bryant BR
- Cutler-Hammer BR

The label says, however: "Use class NI Circuit Breaker, Murray Style MP &EP, I.T.E Style EQ-P Or Westinghouse Quicklag P.

There are only 2 Cutler-Hummer twin breakers that will be easy to replace.
 
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Old 09-03-16, 11:35 AM
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I guess, making panel fully compliant to the rules will be not possible (with a small effort). The problem I see after a short inspection:

- Label says that "The sum of breaker ratings connected to any one stab is 140 amp". The actual sum if you also count a 40 amp (not used) line to the eclectic stove (marked "keep off") is higher on both stubs.

- One of 20 amp / 240 v breakers is connected to #14 wire. This is a dedicated ~20 feet line going to washer/gas dryer. In my understanding, 20 amp is not permitted on #14 even for a short run.

Replacing wire is not simple (runs under the dry wall to a nearby room) and I am afraid, just replacing the breaker will not work as it will trip the 15 amp breaker when washer + dryer runs together.
 
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Old 09-04-16, 07:04 PM
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- One of 20 amp / 240 v breakers is connected to #14 wire. This is a dedicated ~20 feet line going to washer/gas dryer. In my understanding, 20 amp is not permitted on #14 even for a short run.
That is a problem. That breaker needs to be changed to a 15 amp or the circuit replaced with #12 wire.

I also noticed the picture of a tandem breaker in post #5 that I believe is the breaker at the top right of the panel. That specific space can only have a full sized single pole breaker and not the tandem. When I looked closely at that picture of the tandem I see it is a BR1515 non-CTL tandem breaker, but you have a CTL panel. That is another code violation that needs to be taken care of by rearranging of the breakers and using a BD1515 CTL tandem breaker in a space designated for tandem breakers where the stab is notched for the rejection clip feature on the CTL tandem breaker. The non-CTL tandems are "For Replacement Purposes Only" in pre 1968 vintage panels, but many people cheat the CTL system and put them anywhere in a panel that was never designed for tandem circuit breakers. Even the most saavy inspectors will sometimes miss this.
 
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Old 09-04-16, 11:06 PM
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When I looked closely at that picture of the tandem I see it is a BR1515 non-CTL tandem breaker, but you have a CTL panel. That is another code violation that needs to be taken care of by rearranging of the breakers and using a BD1515 CTL tandem breaker in a space designated for tandem breakers where the stab is notched for the rejection clip feature on the CTL tandem breaker.
This seems to be easy to fix - I already ordered replacement breakers to replace the Cutler-Hummer' breakers that seems not be permitted in this panel anyway.

I actually ordered the 'correct' version just because Murray CTL was less expensive - it is good to know that Non-CTL are also not permitted in my panel.

----

P.S. I (obviously) had inspection before buying the house some time ago - it looks like issues like these will be not noticed during the regular house inspection.
 
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Old 09-10-16, 03:01 PM
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I decided to "relocate some 1" double pole breakers and move tandems to that location” to avoid having non-CTL twin breakers in the position designed for single breakers only.

I now see that one of the lags in the double-pole breaker is ‘keyed’, and the corresponding latch in the panel is modified (see below):

Should I modify latch in the new breaker position or buying a new Murray double-pole breaker would be a better idea?

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Another question is related to the rated current of the breaker. I see 30 amp breakers feeding a pretty loaded sub-panel (see below). Are there any sizing rules for the breakers?


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Last edited by igorn; 09-10-16 at 03:32 PM.
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Old 09-13-16, 07:28 PM
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Should I modify latch in the new breaker position or buying a new Murray double-pole breaker would be a better idea?
You shouldn't have to modify anything. I am having trouble understanding that first picture in your last post, exactly what is that?

Another question is related to the rated current of the breaker. I see 30 amp breakers feeding a pretty loaded sub-panel (see below). Are there any sizing rules for the breakers?
The feed breaker cannot exceed the rating of the subpanel or rating of the feeder. You could upgrade the breaker to 50 or 60 amps and upgrade the feeder to 6-3 NM-B cable provided that the subpanel rating is higher than the new feed breaker. It's most likely 100 or 125 amps, but it needs to be checked.
 
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Old 09-13-16, 09:41 PM
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You shouldn't have to modify anything. I am having trouble understanding that first picture in your last post, exactly what is that?
The picture shows the the bottom part of a 30 amp Murray double-pole MP-type breaker and the corresponding latch that (as you can see on the picture) is modified.

I would like to reallocate this breaker to a different position within the panel.

Should I buy a new double-pole breaker or modify the new slot in a similar way?

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Old 09-13-16, 10:12 PM
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The breaker that has been modified should be replaced.
 
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Old 08-06-18, 04:45 PM
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Hi this seems to be a older post i have a question about the 2 black breakers on the very top those are bd1515 which is 2 15 amp breakers it is a single pole breaker! is this actually 2 breakers in one or are they separate breakers on one pole?
 
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Old 08-06-18, 04:50 PM
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Originally Posted by mdh83 View Post
Hi this seems to be a older post i have a question about the 2 black breakers on the very top those are bd1515 which is 2 15 amp breakers it is a single pole breaker! is this actually 2 breakers in one or are they separate breakers on one pole?
They are two breakers (one case) in one space so are on the same pole. That makes them 2 single pole breakers.
 
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Old 08-07-18, 10:07 AM
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the 2 black breakers on the very top those are bd1515 which is 2 15 amp breakers it is a single pole breaker!

Look again and a little closer. The black breaker at top right is definitely a BR2020.
 
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Old 08-07-18, 03:36 PM
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Originally Posted by CasualJoe View Post
Look again and a little closer. The black breaker at top right is definitely a BR2020.
I believe he's looking at the pic in post #1.
 
 

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