Replacing Circuit Breakers

So I'm going to replace a couple of circuit breakers today and I have a couple quick questions.

The breakers in question are Siemens and mounted in a Square D panel. Should I be able to replace these QP breakers with 50 and 100 Amp Homeline breakers? I've found the direct replacement for the bottom breaker but I can't find any reference to the top breaker using google.

The panel is probably about 20 years old and you can see from the picture the Siemens breakers don't fit very well. On top of that, the bottom breaker trips about 3x a day now. The bottom breaker feeds a newer Square D panel with 2X15 amp and 1x20 amp breakers in a garage, none of these have tripped.

Also, do they make low temp breakers, I'm not finding much with breakers this size? This panel is in the middle of a field but these breakers all seem to be rated to 40. It doesn't seem to me like it's tripping due to temp since my understanding is that the lower the team the less likely the breaker would trip due to heat.

Attachment 62991

If it is a Square D panel, get breakers that are compatible to the panel. The top breaker appears to not be seated correctly, or is mismatched to the panel.

Home Depot will carry Square D compatible two pole breakers.
As far as the one breaker tripping 3X Dailey, you may have other problems than a weak breaker, you need to check current draw on the load side of the one that is tripping.

Quote:

---

Originally Posted by SideShow Bob

As far as the one breaker tripping 3X Dailey, you may have other problems than a weak breaker, you need to check current draw on the load side of the one that is tripping.

---

This is what I was thinking, and I know nothing about home electrical.

Mr. Breaker in Highlands Ranch will do R&R on old breakers and lots of new old stock.

Your tripping that breaker because your load is too high on that circuit. The reason the breakers aren't tripping on the garage panel is that the load on those individual circuits aren't too much for that point in the circuit, but it's too much for the main coming out of your main panel. Picture one man holding up 3 people each holding 50lbs. While the individuals holding the 50lbs can handle the load, the one man trying to carry all 3 of the others is too much for him.


You really need to determine the draw on that circuit and modify the main panel accordingly. Too much load on a circuit with a failure to trip the breaker could be devastating. While it's been 30+ years since then, I had extensive residential wiring training but I know my limitations and won't attempt breaker panel work on my own. It's too easy to put my home at risk, violate local codes, etc.

OK, so I'm learning a lot here but no closer to the issue. I went and bought one of the Klein clamp meters to test with.

I'm getting 245 volts on the breaker which I think is fine.

When I test the hot wires on 200/400A it shows 0, when I drop to 2/20A it shows .07 on the black and .04 on the red. I know they should be similar, is that close enough? Do those numbers make sense?

There is very little on the circuits, a couple of lights and a garage door opener is all that is attached to the circuits in the house. There is no correlation between the garage door opener being used and the breaker tripping but I'm going to do some testing and see what measurements I get when the door is opened and closed.

Here's a picture of the inside of the panel in case it might lead to some other suggestions.

Attachment 62994

Tested with every light and every device plugged in turned on, got a steady state reading of .8. Opened and closed the garage door and maxed at 4.8A. That was on the 2/20 setting.

IMHO, breakers can age and relax over time and number of trips and become unstable. If it were me, I would replace the breakers with Square D and then see if you have any other issues.

I also had an issue with one of those dual/shared breakers in my RV. They put the A/C and something else on the same breaker pair. It would always trip when only the A/C was running on a really hot day (100* +) when we were out on the lake. Nothing like coming back to the RV to find it at 130* internal. Replaced the dual breaker with two singles and haven't had an issue since.

If you Amp draw's do not exceed 80% of rating it could be a "weak" breaker.. Most manufacturers state the breaker is designed to only work once. that doesn't mean they will only work once but they will get weak due to varying factors. that's how it was explained to me buy guys that rebuild breakers out at MillerCoors

Quote:

---

Originally Posted by brutal

IMHO, breakers can age and relax over time and number of trips and become unstable. If it were me, I would replace the breakers with Square D and then see if you have any other issues.

I also had an issue with one of those dual/shared breakers in my RV. They put the A/C and something else on the same breaker pair. It would always trip when only the A/C was running on a really hot day (100* +) when we were out on the lake. Nothing like coming back to the RV to find it at 130* internal. Replaced the dual breaker with two singles and haven't had an issue since.

---

This is NOT recommended when you have 240V appliances on those circuits (like well pumps)... because it would pop one leg of the 240V, but the other leg would still be hot. The 2 are joined specifically drop both sides of the 240V. if the circuits serve nothing but 120V, then they shouldn't be joined.

Quote:

---

Originally Posted by Walker2970

If you Amp draw's do not exceed 80% of rating it could be a "weak" breaker.. Most manufacturers state the breaker is designed to only work once. that doesn't mean they will only work once but they will get weak due to varying factors. that's how it was explained to me buy guys that rebuild breakers out at MillerCoors

---

Good info, I'd be surprised if these were less than 10 years old and it has tripped at least 20 times in the last two weeks.

Quote:

---

Originally Posted by th3w01f

Good info, I'd be surprised if these were less than 10 years old and it has tripped at least 20 times in the last two weeks.

---

IF your tire went flat 3x would you keep fixing it? Same for the breakers, Replace with Square D. Then see what issues you're having. More then likely it's the end use item or wiring.

Quote:

---

Originally Posted by Great-Kazoo

IF your tire went flat 3x would you keep fixing it? Same for the breakers, Replace with Square D. Then see what issues you're having. More then likely it's the end use item or wiring.

---

If you go back to my original post, my plan was to replace them before doing any troubleshooting. :) At least I now know how to check the current draw on a breaker.

I finally have an electrician coming out so I'm going to replace the entire panel and go from there. The only end use item I can think of is the opener and that's about 15 years old, so it's going too. Last night it was making a strange electrical humming sound for no reason. The breaker didn't trip but no idea why the opener was making such a loud noise when it hadn't been used in about 2 hours.

Breakers are simply mechanical devices, and mechanical devices fail. Nothing lasts forever. Replacing questionable breakers is cheap insurance, but make damn sure you get the RIGHT ones for replacements! Different manufacturers and panels use their own proprietary breakers/parts, incompatibility is the rule.

Quote:

---

Originally Posted by 68Charger

This is NOT recommended when you have 240V appliances on those circuits (like well pumps)... because it would pop one leg of the 240V, but the other leg would still be hot. The 2 are joined specifically drop both sides of the 240V. if the circuits serve nothing but 120V, then they shouldn't be joined.

---

In my case, the breakers are not "joined," and I didn't mean to imply anyone should ever split a dual pole breaker. What I'm talking about is two single pole 120V breakers built in a single housing that heat soak and cause unnecessary trips. I believe they call these tandems or "cheaters."

http://www.structuretech1.com/wp-con...02/Tandems.jpg

Quote:

---

Originally Posted by brutal

In my case, the breakers are not "joined," and I didn't mean to imply anyone should ever split a dual pole breaker. What I'm talking about is two single pole 120V breakers built in a single housing that heat soak and cause unnecessary trips. I believe they call these tandems or "cheaters."

http://www.structuretech1.com/wp-con...02/Tandems.jpg

---

Those are half breakers. They make 2 circuits off the same phase of that slot. The slots are phased A, B, A, B.............. Starting from the top slot.

To the OP, the wiring to that bottom breaker is way undersized for the rating on the breaker, ( 100 A ? It is too faded to read from the picture ), especially if it is of any length, if I recall you said approximately 100 feet.
Not only do you need to replace the breakers, you need to upsize the wire size using the de-rating for the distance to the equipment.

New 50A breaker installed in place of the old 100A, this is actually an old Siemens panel. Total load of all breakers in the sub panel is 50A and highest measured while running everything including opening and closing the garage while turning on the TV is ~7A.

A Phase input wire connector was loose so I tightened that.

Attachment 63132

Quote:

---

Originally Posted by SideShow Bob

To the OP, the wiring to that bottom breaker is way undersized for the rating on the breaker, ( 100 A ? It is too faded to read from the picture ), especially if it is of any length, if I recall you said approximately 100 feet. Not only do you need to replace the breakers, you need to upsize the wire size using the de-rating for the distance to the equipment.

---

The wire run is probably 60 - 100', what gauge would be required to support the 50A? I've been searching but I don't understand the answers at this point. It the wire looks to be 6 - 8 gauge but that's just a guess.

Bob I don't mean to be a jerk but you are incorrect and if you would like I will put a 200 dollar bill down on each of the things I am going to say and will directly donate your money to the OP.
Starting from the top. 60 Amp 2 pole breaker A Phase , B Phase, 240 V Next one down 15-15 twin each circuit of this Siemens ITE twin is A Phase 115V - A Phase 115V because it connects to the A phase buss, Next one down is a 20-20 twin each circuit of this breaker is B Phase 115 V - B Phase 115 V because it is attached to the B phase , the next breaker down is a single pole 20 full size breaker and is on the A phase. This has so many code violations that it should be shut down. The number one reason your breakers are failing is corrosion from water damage, you can see this by the white water marks on the breakers in the first pick. Bob if this was a GE load center GE calls there breakers like this " thins " and the Buss arrangement is set up different. If a breaker is sized properly 80% of the full load of the nameplate rating of the appliance and if it is a continues motor load you need to add 125% to that calculation and the wire is sized properly for voltage drop 2*K*I*L / CM The breaker will not over heat.

Quote:

---

Originally Posted by TheSparkens

Bob I don't mean to be a jerk but you are incorrect and if you would like I will put a 200 dollar bill down on each of the things I am going to say and will directly donate your money to the OP.
Starting from the top. 60 Amp 2 pole breaker A Phase , B Phase, 240 V Next one down 15-15 twin each circuit of this Siemens ITE twin is A Phase 115V - A Phase 115V because it connects to the A phase buss, Next one down is a 20-20 twin each circuit of this breaker is B Phase 115 V - B Phase 115 V because it is attached to the B phase , the next breaker down is a single pole 20 full size breaker and is on the A phase. This has so many code violations that it should be shut down. The number one reason your breakers are failing is corrosion from water damage, you can see this by the white water marks on the breakers in the first pick. Bob if this was a GE load center GE calls there breakers like this " thins " and the Buss arrangement is set up different. If a breaker is sized properly 80% of the full load of the nameplate rating of the appliance and if it is a continues motor load you need to add 125% to that calculation and the wire is sized properly for voltage drop 2*K*I*L / CM The breaker will not over heat.

---

Calm down everyone. MY post/picture was only an example I found online of the cheater breakers I replaced in my RV, nothing really related to the OP, just color commentary about what can happen to breakers to cause them to trip - degradation, etc.

That looks to be # 10 Copper and should be # 4 Aluminum or # 6 Copper at 100' length. Maximum over current protection for a number 10 wire is 30 Amps period. QUOTE=th3w01f;1944735]New 50A breaker installed in place of the old 100A, this is actually an old Siemens panel. Total load of all breakers in the sub panel is 50A and highest measured while running everything including opening and closing the garage while turning on the TV is ~7A.

A Phase input wire connector was loose so I tightened that.

Attachment 63132



The wire run is probably 60 - 100', what gauge would be required to support the 50A? I've been searching but I don't understand the answers at this point. It the wire looks to be 6 - 8 gauge but that's just a guess.[/QUOTE]

I also should have said your #10 copper will be fine at that 7 amp load at that footage with the proper 30 amp breaker.

Quote:

---

Originally Posted by TheSparkens

This has so many code violations that it should be shut down. The number one reason your breakers are failing is corrosion from water damage, you can see this by the white water marks on the breakers in the first pick.

---

TheSparkens, I want to clarify what you're saying. Most of your post is referencing the picture from burtal but this last part sounds like it's about my picture. This panel has probably been untouched, in the same place in a field, for 20 years and there is a lot of corrosion on the bus. I had an electrician out yesterday to look things over with me and we're planning on replacing it once it warms up a bit.

Other than the double tapped ground, what code violations do you see? I want to make sure I'm addressing everything properly.

If it was my pic you were referencing, here's a better picture.

Attachment 63140

Quote:

---

Originally Posted by TheSparkens

Bob I don't mean to be a jerk.

---

But you are.........

Your post went about two miles over the OP's head....

I was just trying to make a over simplified description of an electrical panel to the OP.

As far as to what a half breaker is called it all depends on who and where you did your apprenticeship at. There are diffent trade names for items in different regions across this country.

Replacement will fix it all. I would not use an electrician that installs a new breaker of that size on that size of wire.

Quote:

---

Originally Posted by TheSparkens

Replacement will fix it all. I would not use an electrician that installs a new breaker of that size on that size of wire.

---

The new breaker was my doing but it was replacing that old 100A that kept tripping. No tripps yet but we'll see over the next few days, from 2 - 3 a day, this has been an improvement so far.

Serious question here, does the size of the breaker actually make any difference in this case? I'd already installed the 50A before I read your post about installing a 30A so I left it, but I'd really like to understand this piece and I can easily swap it for a 30A if needed.

With everything plugged in and every light on it doesn't even hit 10A load during startup of things like the garage door opener and TV and the constant load is MUCH lower. Given that the panel this is feeding has 2 X 15A and 1 X 20A, if something was to suddenly pull a much higher load shouldn't it trip one of those breakers first? Given what's running off the panel, I can't see a scenario where the combined load would exceed 40A (135%) or 60A (200%) of the 30A breaker. I understand redundancy, is the reason for the 30A also based on the shorter allowable trip time vs the 50A?

I measured today and it's about 50' from panel to panel so probably 60 - 70 total, depending on how it's run.

PM me it looks like we live in the same area and I can come over and look and explain all of this and look at your system. It doesn't matter what part of the country one is from the code is set up to protect people from bodily injury and fire that is caused by electricity. I will not charge you, I have been an electrician for over 35 years and never fail inspections because of code violations. If you don't want it installed correctly then don't call.

Quote:

---

Originally Posted by SideShow Bob

But you are.........

Your post went about two miles over the OP's head....

I was just trying to make a over simplified description of an electrical panel to the OP.

As far as to what a half breaker is called it all depends on who and where you did your apprenticeship at. There are diffent trade names for items in different regions across this country.

---

Yeah I call them half breakers as well

It's not about what it is called. We can go on forever about that or most parts how about a F-strap, battle ship, pistol strap, gun boat its about the safety of that panel and after looking at it, its not that bad. It does have water damage and after removing the breakers the water was setting on them at the time of removal, Because it is in the middle of the field it is subject to expansion of the soil and there is some damage because of that, the buss bars are corroding because of the water and the aluminum has some pretty good oxidation but all of this can be repaired with a little help and the OP has a very good electrician (Not recommended by me but I do know him) that will be working on it and other things like sizing the breakers properly because none are overloaded just over sized for the type and size of the wire that it is terminated to the breaker, sealing the panel so water doesn't get inside and repairing the broken and exposed conduit and wire so he doesn't get any more damage he will be good to go. To the OP it was good to meet you and you have a great place.

I always called those breakers "tandems" along with the other electricians that I associate with. I'm not an electrician but that's what I've always have heard them call those types of breakers...

Usually used when you're out of space and you need another circuit.