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Tandem Breakers vs Capacity

13K views 35 replies 10 participants last post by  frenchelectrican 
#1 ·
This is the first question for me and I apologize if is has been previously answered. My home is equipped with 2 ea Challenger 200 amp 20 slot main panels ( 400 amp service) with a total of 40 slots. I am in the process of completing a total load calculation for my home. When the home was built 15 years ago, the electrician told me that he had installed many circuits so that we would never experience the dreaded light flicker, etc. He unfortunately used up all 40 1" slots. I would like to add additional circuits in the unfinished portion of my home for lights, standard 110v hand power tools, and general use receptacles. Assuming the existing loads are far from capacity, how many tandem BR2020/ BR1515 breakers can be legally/practically installed in the panel boxes? I noticed that the Challenger 200 amp Panel came in 20, 30, & 40 1" slot sizes. Thank you for your response.
 
#3 ·
After looking at the the label on the covers, I did not see any reference to "Mini". However, for branch circuits, the label lists Type A, C, HAGF, GFCH where Type C is 1 pole and Type A is 2 poles. The " typical wiring diagram" on the cover shows a 30 slot main panel with the 1st 10 slots each side as Type C and the bottom 5 slots on each side with 5 Type A breakers.

Assuming that I install a sub panel, how far away from a utility sink does it have to located? Available wall space in the utility/mechanical room is at a premium.

Thanks for your previous answer.
 
#5 ·
400 amp service. That alot of juice for a house. Whats your square footage?????
If you cannot understand the markings in your panels then contact the manufacturer and see how many tandems are allowed and where they go. Use a sub panel as last resort.
 
#7 ·
Thanks for the interest in my question. We have approximately 6000 conditioned sf with another 800 sf of shop area and 900 sf of attached garage. The two existing finished floors are 4400 sf with a couple circuits utility/light circuits in the unfinished (2400 sf with shop) area. I would like to finish the downstairs and anticipate more circuits (10 or so). Unfortunately the panels are Challenger nla so no help from supply sources or pdf. files. The Cutler Hammer BR series breakers are the proper replacement. Obviously, when I spec'd the 400 amp service, I wanted room to grow and add circuits. As I have previously stated, I can't determine if the panel is restricted to 20 1" breakers or 40 1/2" breakers ( 20 tandems) or a combo of the normal 20 and 10.
I'm not doing anything unusual, just a 4BR/ 4 1/2 bath with an unfinished lower level to become a hobby room, shop area, large den, BR & bath. I have recently replaced my old 2 gas water heaters with 2 Rinaii tankless heaters, and the cooktop is gas. So the major demand is a 50 amp dbl oven circuit, 30 amp clothes dryer, 50 amp main floor AC, 30 amp upstairs AC, and 20 amp lower level AC. We have a lot of 15 amp can light circuits, and a lot of 20 amp receptacle circuits including GFCI for kitchen and baths. I am compiling appliance rating data to plug into the NEC ampacity worksheet to determine available capacity.
 
#11 ·
How big is Al Gore's family? :whistling2:

Quote:

An obscure conservative group in Tennessee claims to be offering up the utility bills on Al Gore’s 10,000-square-foot Nashville mansion.

The group cited some damning kilowatt-consumption figures — 221,000 for the Gores in 2006, compared with the American average of 10,656.
 
#9 ·
often, the panel designation will include the number of circuits it will hold. Something in the line of a XXXXX30/40 or such. Can you give us the panel model?

depending on what code cycle you are under, that may be irrelevent anyway. Up through the 05 code, you would be limited to 42 circuits. If under the 08 code that limitation was removed under most circumstances (don't have my 08 handy to tell you for sure but I believe your limitation would be removed).
 
#13 ·
The panels are Challenger SL 20(30-40) CT
200 AMP Max, Type I Enclosure

These panels were manufactured in 1993.

Actually, my wife and are empty-nesters. After putting our kids through college and getting them married off....college and weddings are sure expensive....its now time for US to pursue some quality time together. Yes we have too much house now, but we love it! Another 15 years and we'll cash it in for the "retirement home".

I did not see the designation as described on the label. I have taken a picture of the panel label and hopefully someone can "break the code." Please see the attachment. Thanks for all the interest and help!!:no:
 

Attachments

#17 ·
Even if it is only a 20 space it is 99.9% sure that it is a 20/40.

When was the last 20/20 or 20/30 200 amp panel anyone saw???

Yes, the label is misleading. According to it HH is correct, but according to the original post Nap is correct.
Either way, if it is a 20/40 then the WHOLE panel can be filled with twins.
 
#26 ·
I am not familiar with Challenger panels. I have seen stranger things.

All I know is if you look at the pic, there is a hard line after the top 20 breaker slots and it shows only the larger breakers indicated for that section. OP states there are 20 spaces, not 30.

That is why I believe the label is a generic label. It appears to include the 20 circuit panel and the 30/40 circuit panel.

the fact the panel will not accpet the 1/2 inch breakers supports my point. The 30/40 panel is designed to accept 1/2 breakers on the last 10 spaces (5 each side)

as stubbie was posting, the smaller breakers are the side clip type and it indicates these in the last 10 spaces. If these cannot be used in the OP's panel (he said he couldn't), then he has an only 20 circuit panel. It would technically be illegal to use the 1" piggyback breakers because it is listed as only a 20 circuit panel.
 
#22 · (Edited)
Thats exactly what it is. This panel is a 'slim line side clip challenger panel' it will accept 30 type C full size single pole breakers (no side clip) or 20 type C's and 20 type A slim lines. So 30 or 40 single pole circuits. The type A side clips are like GE 1/2" thqp's only they have a side mounted clip. You have to order them either left side clip or right side clip in order to stack them. The slim lines type A also come two pole with handle tie bar. A single pole 20 will be TBL120 or TBR120 depending on what side clip you need. The first one of these I worked on I went in to the supply house and asked for some challenger slim lines and counter guy said left or right clip....I hate it when the guy can tell you haven't the foggiest idea.

 
#25 ·
Gentlemen;

Thank you all for your input. The two panels in my home are 20 slot, not the 30 slot as shown in the diagram attached to the panel door (see picture above). That's exactly my dilema. Does it become a 10 + 20 with the tandems or can it become a 0 + 40 with all tandems? The 10 + 20 would give enough circuits with some planning and load balancing to do what I would like to do. As you can see in the branch circuit column on the spec sheet, it lists that the panel will accept the tandem in all branch slots. The bus bar is consistent from top to bottom and requires the tandem breakers (1" total width) versus the mini 1/2" breakers. The breaker slides onto the contact tab perpendicular to the bus bar spaced at 1" intervals starting at 1/2" from the top of the slot. My point is, the bus bar design does not restrict (as some panels do) the placement of the standard vs the tandem breakers in top portion only. If a common design is 40 circuits per 200 AMP, then why would these 200 amp panels be different?

Again thanks for the input as I am learning a lot about the differences in the equipment.
 
#27 ·
NAP said

I believe that is a generic label for a 20 circuit panel as well as a 30-40 circuit panel.
It certainly appears you are right....:thumbsup: the challengers I'm familiar with I believe were manufactured by Sylvania and then bought by westinghouse and then bought by cutler hammer....Sounds like our banking system....:)

Sooooo I better read the whole thread next time....

I don't see how you add circuits to it if it is full, at least not and stay within the listing.
 
#28 ·
Again thanks for your thoughts. This weekend I was on the professional chatroom lurking and I discovered that the Cutler Hammer tandem breakers are acceptable to use as Cutler has put out a notice to tape to the Challenger Panels stating that the BR2020 etc breakers are certified by NEC(?) for use. Any ideas where I could obtain actual manufacturer's spec/ code rating, interpretation? The whole thing doesn't make real sense to me in that only 20 circuits for a 200 amp main panel would have been designed. I am a degreed Mechanical Engineer and I run into these quirky situations and you have to drill down to the original specs, written word, certification which may or may not be the typical interpretation or use. Thanks agin for your insight.
 
#31 ·
I have worked with these Challenger and GE panels in the past. Looking at the bus stabs will make it very clear if they will accept the slim breakers or not. The stabs will have a T bar on the stab in the positions which will accept the slim breakers. This would be easy to check by pulling out the existing breakers and looking.

Did I say what I am thinking or just confuse the issue?
 
#33 ·
The Cutler BR2020 breakers fit the panel just fine. I have not pulled one of the upper breakers to see if it will fit there, but I do remember that the bus stabs were consistent. As soon as I finish the present load calc and determine my anticipated added load, I can then work on balancing the load along the 4 legs. I'm seriously considering replacing both with new 20/40 panels and be done with it. I don't want or need an inspector giving me a hassle about whether it is or is not expandable. The load will not be a problem, just the circuit number. Again, thanks to all who have responded and I appreciate the humor in some of the comments even though I have not specifically responded.
 
#35 ·
I just had a thought. I'm traveling this week so I can't check right now, but if the panels are fully convertible to 40 circuits, would the neutral bar have spaces for 40 neutrals? Or would the need to add another neutral bar be considered an accessory upgrade to permit the expansion? The electrician who wired my house was a nice young man who installed the central vac piping for me while he was doing the wiring. The fact that he knew I was going to expand the lower level.... I don't think he would have supplied 2 non -expandable panels. I may run by the local electrical supply house and check with the guy there. I'd be willing to bet that my equipment came from him.

Thanks to all who have responded!:)
 
#36 ·
I really don't recall see a 1Ø 200 amp load centre with 20 space but in 3Ø 200A 18 space yeah I did see it.

The Challanger panel yes it do have right and left tab in there but it been a very long time senice i did see that thing :whistling2:


But as Stubbie show the photo it look very simair to that.

And there is a subsance diffrence between the old challanger and GE breakers are the bussbar tabs that only way it will get ya.

Merci,Marc
 
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