Load Centers

Several load centers are typically sourced from a main switchgear from separate distribution breakers. NEC in the USA is one commonly used code, but it's up to local building inspectors whether or not you will be allowed to do what you ask.

To answer your initial question, as far as I am aware - no.

The following should address your second question;

In my local, the term "Load Center", describes a non bolt-on breaker type, residential board? If this is what you are describing, I would not try to couple the two of these together due to the (typical) maximum 10 KAIC rating and non bolt-on breaker feature.

I would instead go to a "Panel Board" type panel. Depending on the anticipated loads, you can order this with a beefed up KAIC rating if need be, plus breakers are of the bolt-on type.

"Panel Board" type panels are better suited for this type of an application. They are of heavier design/construction than a "Load Center".

For example, you can take one 42 Ckt., 200A, MBO panel board and provide a 200A, 3P branch CB to feed the second panel board which can be a 42 Ckt., 200A, MLO board due to over current protection being provided by the branch breaker in the MBO panel board.

The actual amperage of the boards will depend on the supply breaker/feeder size based on how many amps your loads will be.

The example above is based on the US NEC and the assumption that the two panel boards will be placed next to each other.

KAIC = Kilo-Amperes Interrupting Capacity

MBO = Main Breaker Only

MLO = Main Lug Only

Hope this helps – KJK/USA

kAIC ratings have nothing to do with it.

Nobody makes a Load Center or Panel Board with more than 42 circuits as a standard product. If you are willing to pay through the nose, most of the majors (Siemens, Sq. D, Cutler hammer) will make you anything you want. But the official way to get more than 42 circuits using off-the-shelf products is to buy a 42 ckt panel and what are called "Sub Feed Lugs" for it, to feed an adjacent 2nd panel with however many more circuits you need. The conductors used to feed the 2nd panel must be the same size used to feed the first. If the 2nd panel is more than a few feet away (not sure of the distance) then you need to do it with a feeder breaker as mentioned above.

Friends,

OOPS to all of you! In the USA, the restriction to 42 circuits in the National Electric Code was removed in the 2008 edition. Square-D makes, advertises and markets larger load centers now (to name one manufacturer I am familiar with). Their product line in the Load Center category is limited to 40-42 spaces and 60-52 breakers (using tandem units). In the Panelboard category it goes all the way up to 84 spaces for either plug-in or bolt-on breakers, with main lugs or main breakers up to 600A.

You are left with a separate limit to the number of branch circuits you can have in a panelboard--the maximum height for a handle. If you are dealing with a panelboard with a main, and have it mounted above the finish floor (wise to avoid it getting wet or damaged by floor cleaning operations), and subtract the height for the bottom wireway and terminal area, then the available height for branch breakers is reduced by the sum of all these allowances. In the Square-D product line, for example, the box for a main breaker 84 space panelboard is 80 inches high.

Regarding the second question--the other replies are correct. Normally done with feed through lugs.

--John M.

A load center panel is exacly what it is. A load center. It has no main breaker to protect the bus, the protection is either at a switch gear or fused disconnect on the prime or sec. side of the TX

Duah

Oh what is the rating of your 120/208 Delta Panel? Is you want like 400/800A rating... you could probably get a 84 cct but you will pay for it.

Your best bet would be would be to install 2 load center panels side by side and fcourse install 2 fused disconnected on the secondary not only for isolation but also to protect the main bus/cable.

Way cheaper then purchasing an AB or CH twin-panel.

Another possibility is to double lug 1 panel and have those lugs act like a splitter to a same panel right beside it.

IE. you need 400A max 84 cct..... Well you will installl a fused protection on the high sider of the 600V /208V Tx and have the secondaery feed the first panel and right beside it have the other panel.

Depending where you are doing this. The code would require for roughly 500MCM cable for the secondary (and betweeen the 2 panels). and 250MCM on the primary of the TX. Now those are decent size lugs!

To save labour, pipe size, conductor size.... and cost!

transformer-----> splitter-----> Panel #1 & Panel #2 or 2 seperate fused disconnects.