Talk:Distribution board

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Canadian imperialism

Is "Dief box" a common phrase other than in Canada? I could only find one reference with Google, and that was to a Canadian manufacturer of distribution boxes. --Wtshymanski 23:11, 4 May 2005 (UTC)[reply]

Never heard it used in the UK Rob cowie 20:51, 17 January 2006 (UTC)[reply]

Duplicate picture

A fine picture, but do we need it twice in one article? And shouldn't the article indicate that panelboards usually have a cover (even in the UK, I assume). --Wtshymanski 03:33, 18 January 2006 (UTC)[reply]

You got a pic (under a suitable license of course) of a board with the cover on, maybe we could use that as the initial picture. the reason for the duplication is i wanted pictures asside detailed descriptions (which were way too long for an image caption) but i still wanted to have a picture in the standard initial picture position. Plugwash 14:29, 18 January 2006 (UTC)[reply]

GE/US board pic added. 68.39.174.238 00:28, 28 March 2006 (UTC)[reply]

We've got a live one!

The article currently contains the following statement:

American breaker panels commonly have many live parts exposed with the lid off.

While it's true that our panelboards (load centers, etc.) have exposed live parts, I think I'd disagree about the word "many". Basically, the readily-exposed live parts are limited to the 1, 2, or 3 phase bars and their associated connection lugs. The terminals on the individual circuit breakers are usually shrouded so you'd have to make an effort to contact them. I gather that continental breakers have about the same exposure.

Any thoughts?

Atlant 14:45, 18 January 2006 (UTC)[reply]

(I agree with Plugwash's edits -- thanks!)

Atlant 14:57, 18 January 2006 (UTC)[reply]

I was wondering if someone else noticed that tone in this. I have no objection to the fact that the British ones may have a shield over the incoming lines, but the way it's stated (Twice for that fact, and the comments about "better safety") make it seems like it's trying to make a case against US (Or for UK) boxes.

Almost forgot this one, what exactly is a "IP20" ?

See Ingress protection rating Plugwash 19:22, 20 March 2006 (UTC)[reply]

New one on me... 68.39.174.238 16:48, 21 March 2006 (UTC)[reply]

Its not just the incoming lines that are covered. Its the main busses, the bulk of the breaker terminals (the screws are visible but not touchable with a finger) and everything else. If the board has been wired correctly its perfectly safe to take the lid off with the power on (you do generally expose a live part when you remove a breaker or blank though) . Plugwash 17:25, 21 March 2006 (UTC)[reply]

You mention dead front but fail to discuss anything in regards to Arc Flash. For residential no you really dont have to worry about it much but in commercial or industrial applications you best have the proper PPE on depending on the circuit (even for a 20 Ampere single phase). You also make it sound like all Circuit Breakers are rated for switching duty which is not the case and simply stating a C/B is used to de-energize a circuit for servicing is a somewhat incorrect statement considering the primary design is to clear faults. Circuit Breakers are NOT "safety switches". —The preceding unsigned comment was added by 64.252.208.50 (talk • contribs).

Hmm, maybe this is a difference in regional practices but i'm pretty sure the MCBs used in the uk are designed to be able to act as isolating switches. Plugwash 14:21, 21 March 2007 (UTC)[reply]

The name

While I think this is the most likely "internationally" understandable name, I suggest adding "electrical" to it, so it's more obvious on looking at the title what it is, since it's probably not immediately understandable to someone who isn't familiar with this turn of phrase. 68.39.174.238 08:41, 20 March 2006 (UTC)[reply]

Upside down picture?

That so-called "American" panel is very strange looking to me...you're not supposed to have the line lugs at the bottom! It may well be a Code violation, too. It is certainly unusual and I've never seen one with the live feed at the bottom. --Wtshymanski 18:50, 21 March 2006 (UTC)[reply]

I don't think there's anything in the code that requires your line lugs to be at the top. In fact, the instructions for a Murray (?) distribution board specifically described the board as being invertable.

Atlant 00:11, 22 March 2006 (UTC)[reply]

While I'm pretty sure it's legit (A public building I'm regularly in, that is not that old, has some like that), however it IS defiantely VERY strange comparatively, especially WRT residential installations, which I think are probably in the 90th %ile top-feed boxes. I have a pic of mine (Top feed) which I intend to upload to illustrate that as well as give a better example of the entire box, not just the line in part. Also, weird colors for a "US" box (IMAO, I haven't seen in a really new box though). 68.39.174.238 00:26, 23 March 2006 (UTC)[reply]

I looked through my CEC and NEC and couldn't find a prohibition - but I'm pretty sure there's a NEMA spec that says power should come in at the top. The panel shown is a 3-phase panel, which explains all the colors - unusual for a single-family home. It's also unusual in that it is a sub-panel - no main breaker, not a service entrance. Contrary to the caption, you can see the white neutral wire but it's not easily made out in the thumbnail image. --Wtshymanski 18:49, 23 March 2006 (UTC)[reply]

Weird... and its in his (her?) LIVING ROOM... Gotta wonder where they live... a lighthouse? 68.39.174.238 22:58, 27 March 2006 (UTC)[reply]

Careful: the lack of main breaker might not mean "sub-panel", it might just mean that it has a remote main breaker. This is the fashion in which my house is wired: the service entrance and main breaker is out in the garage near the meter and a length of SE cable connects to a lugs-only distribution panel down in the basement.

Atlant 19:33, 23 March 2006 (UTC)[reply]

Panel boards, or load centers, depending on the brand, may be configurable for bottom or top feed. The reason is so that the service entrance cable does not have to make a U-turn anywhere when feeding the panel - if it comes from above or from below. SquareD's QO panels are a perfect example. JAK83 05:57, 5 February 2007 (UTC)[reply]

I second this, with one small exception...As long as you don't violate wire bending space and radius as specified by the AHJ, and you abide by manufacturer's specs, you can do any damn thing you want with your panels. Top, bottom, backfeed, you name it. If you know what you're doing this should be a non-issue here (read-this comment thread should not exist) (64.50.228.36 03:04, 6 September 2007 (UTC))[reply]

Folks, I have been an electrical designer for nearly 20 years in industrial engineering with projects on 5 continents. Please take it from me, feeding a panelboard from the bottom is permissible and common -- in fact, most panelboard manfacturers design the interiors to rotate 180 degrees (invertible) within the enclosure to allow for top feed or bottom feed. Also, according to the IEC/NEC (NFPA 70), a main circuit breaker is not required anywhere unless a panelboard has more than 6 branch circuit breakers, which most do.

Now, here's what really throws people for a loop -- an otherwise normal branch circuit breaker may serve as a main circuit breaker (a.k.a. "back-fed") for a panelboard, energizing the bus bars and the branch circuit breakers. Of course, it must have sufficient current rating to serve as the main circuit breaker. 60 ampere and 100 ampere, 2-pole or 3-pole circuit breakers of the branch variety are often used as "main" circuit breakers in panelboards to avoid the expense of line lugs. Danger! Learn your stuff or hire an electrician to risk his life instead!

BTW, this article is full of misinformation and sloppy misuse of terminology, but I don't have anymore time to spend on it -- back to work. 204.58.248.32 (talk) 20:11, 1 April 2009 (UTC)[reply]

Pics

I've added a few of my own pics. I'm open to comments on all parts of the change. Thanx. 68.39.174.238 01:41, 28 March 2006 (UTC)[reply]

sub-panels?

The article is much appreciated. A discussion of sub-panels common in today's construction would be appreciated by me. Especially the limitations on them. For example is it legit to add a 200 amp sub-panel(s) with its own main breaker by attaching the new sub-panel to the entrance lug on an existing main panel?Fried! 03:31, 29 September 2006 (UTC) In other words can one add a 200 amp sub-panel to a 200 amp panel which is already occupied by for example 150 amps of breakers?Fried! 03:39, 29 September 2006 (UTC)[reply]

I'm no electrician, but I don't think that's legit. I'm reasonably sure that (at least in residential setups), there has to be a single "MAIN" breaker that will cut off all power service. 68.39.174.238 21:12, 9 December 2006 (UTC)[reply]

NO!!!!!!!! That is downright scary. Anyways... a 200A sub-panel? Are you feeding an entire separate house, like your neighbor? The next device after the meter has to be the main breaker (even if there is a separate service disconnect near the meter.) If your existing load center is 200A then your service entrance cable and meter are probably rated for that also. Your power utility would have to install new service entrance cable and meter if you need another 200A of service. HOWEVER, you could easily (and safely) add <50A sub-panel fed from your existing main load center by replacing four single space / single circuit breakers with two single space / two circuit breakers, making room for a 50A two space breaker for your sub-panel. BTW, what is it you need 200A for??? 50A should be plenty for a workshop or garage, even a large addition. JAK83 06:07, 5 February 2007 (UTC)[reply]

Electricity Demand

It would be interesting to note how much the amp rating of main breakers has risen over the years, like in the 1920s a U.S. house may have had a 50A or 75A main breaker, and today new homes are built with 150A, 200A, and 250A main breakers, just to keep up with the demand for electric stuff.

I noticed while I was in Japan, their household electric is a split-phase system like the U.S., 100V phase-to-N and 200V phase-to-phase, however, it is not uncommon for a Japanese home to have a main breaker of only 30A. JAK83 06:18, 5 February 2007 (UTC)[reply]

Subpanel?

I need to add a 50-amp circuit, but there is no romm in my service panel(only a single space left). Can I have a subpanel connected to the main service panel to house the 50-amp breaker or do I have to have a larger main service panel box installed?68.111.179.103 01:10, 23 April 2007 (UTC)[reply]

I'd suggest you contact a local electrician (preferablly several) in whatever judristriction it is you live in. Regulations on this sort of thing tend to vary quite a bit arround the world. Plugwash 14:04, 23 April 2007 (UTC)[reply]

Second the above comment: We have no idea where you are or what the local rules are. 68.39.174.238 15:21, 14 July 2007 (UTC)[reply]

Third the above comment. Electricity can be a tricky beast. Often, electrical code is even worse. If you would allow me to make this loud, plain and crystal clear on this little island within this great forum...if you don't absolutely know every discrete and minute detail of what you're doing, please PLEase PLEASE STAY THE HELL OUT OF YOUR FUCKING PANELS! I'M NOT KIDDING HERE!! If you don't have the brains or spare change to hire a real expert to do this sort of work, it's my opinion that there's a good chance you're not smart or safe enough to do or even need what you think needs to be done.(64.50.228.36 03:04, 6 September 2007 (UTC))[reply]

Just to answer the question, no you can't, because you need a breaker on the feed to the subpanel! The best thing to do is to remove three single-pole breakers from the main panel, install your (presumably two-pole) 50-amp circuit and another two-pole 50A breaker for the subpanel, and relocate the three removed breakers to the subpanel. (Adjust the numbers appropriately if you need three phases.) Hopefully it's obvious that anyone not aware of this important safety rule probably shouldn't be installing their own mains wiring. 71.41.210.146 (talk) 17:16, 26 January 2008 (UTC)[reply]

Always is a strong word

I wonder if the phrasing "For 480Y/277 volts (always three-phase)" is misinformative. While I agree that 480Y/277 is by far the most common occurance of 480 volts phase to phase, I have heard through second-hand sources that 480/240 single phase systems do in fact exist and that utilites will connect them. Unusual, to be sure, but for the sake of completeness and accuracy this could be addressed. But not by me.(64.50.228.36 01:39, 6 September 2007 (UTC))[reply]

Wow

I don't know who this kid who sprayed a lot of this garbage on this topic was, but I'm scared to think that s/he is an electrician somewhere. Is it possible for articles that relate to this one major thing that everyone takes for granted, and that I know and love, to be joined under a wikiproject? Some of the stuff I've seen overall on the subject worries me. Experts please, preferably those who know just a bit more than white is neutral and bare/green is ground (earth for you "other" folks hahaw). (64.50.228.36 02:33, 6 September 2007 (UTC))[reply]

UK CU pic

Domestic CUs, which will be familiar to most readers, don't normally look like the current pic. Domestic CUs are almost always single horiztonal row, and the boxes are nowhere near as big as shown. Maybe someone has a pic that better represents most people's experience. Tabby (talk) 03:06, 8 December 2007 (UTC)[reply]

I have such a pic but I'd like to keep the three-phase pic alongside it, as this article is about both. The section name "UK Fuseboxes (Consumer Units)" may be a problem though as it tends to indicate that only domestic CUs are the topic. Anihl (talk) 22:30, 17 December 2008 (UTC)[reply]

UK Fuseboxes (Consumer Units) - categories - and stuff

I'm not clear what value the categorisation "Modern CU with MCBs and an RCD / Older CU, usually containing no RCD" has - many early MCB installations were done with no RCDs. I saw these regularly in the 1980s. Does anyone think this is really useful? Anihl (talk) 22:30, 17 December 2008 (UTC)[reply]

Making a few amendments to this section then, including renaming it so that the title allows for all types of board. Amongst other changes, I'm deleting the separate section on Split CUs, which is not strictly accurate (a split busbar must still be supplied through the main incomer for the board - being RCD protected does NOT in itself make the section separately switched). Previously added some pictures of actual fuse boxes; I'll get some shots of Bakelite and modern CUs at the next opportunity. Anihl (talk) 03:01, 25 December 2008 (UTC)[reply]

SVG Open Source Graphic

I have created a SVG that is Open Source that might be really nice for this page. I added a link at the bottom of the ARTICLE to the graphic in EXTERNAL LINKS so everyone can see it. The graphic is generic and I could modify it some for the Wiki if needed. It is also nice for mapping out ones circuits, or as a starting point for a more specific non-generic panel. VitalBodies (talk) 02:59, 16 May 2009 (UTC)[reply]

Two Phase or Split Phase?

I find the table under Breaker Arrangement to be somewhat ambiguous. The phase labels for split phase are A, B, A, B. It seems as though it would be more accurate to label them something like A, -A, A, -A. Kmuret (talk) 14:44, 12 January 2010 (UTC)[reply]

I think L1 and L2 would be the correct way of denoting two legs of a split-phase service. A and -A would imply that a load connected between the two legs would yield 0V (A-A=0), where in fact it is (should be) twice the single-leg voltage.Noderaser (talk) 04:32, 15 June 2010 (UTC)[reply]

panel board

The term "panel board" used to redirect to this distribution board article. I changed the redirect to point to control panel (engineering) instead. Have I made a horrible mistake? --DavidCary (talk) 19:08, 5 July 2013 (UTC)[reply]

19th June 2014 edit

Is the 19th June 2014 edit definitely an improvement? It's worded in the first person and is rather bias towards the outdated system - the "old and loved" colours, etc. 92.28.252.70 (talk) 23:12, 20 August 2014 (UTC)[reply]