800 Amp 35kA Distribution Block

N

NeilWicks

Member
Location
USE
Occupation
Engineer
Context:
I need an 800 (or 760) Amp Distribution Block for a panel to be rated at 35kA
The panel will be fed from an 800 Amp Circuit Breaker in the MDB about 10 feet away with 2 x 500
Total load in the panel will be 560 Amp with the largest load being 77 Amp
Need a little spare capacity above the 560 Amp of at least 100 Amp for some future additions

Problem:
Can not find a suitable Distribution Block.
All the Distribution Blocks I can find are only rated above their nominal 5 or 10kA when used in conjunction with 600 Amp Type J Fuses or a specified 600 Amp Circuit Breaker or similar, but nothing greater than 600 Amp

Question:
Any recommendations for a solution ?
And would a configuration as shown in the image work ?
And if it would work, would it still work without linking the two Distribution Blocks ?

AICyYdaUVeIe8erGvChzfNQG9y-O6prSyk9jL7arVPvQ77GptAVS_1KePSvea3qAlojSh2vfiuX3xj8JTsQZ8dA9SjtSzGyhdwiPOZJuqrKJ9JRyMWTr6JWbtlohz1gQhw_1ET77yvFARSH5xibxy_7B7Hz7De-PXnbJYEimjyoXM35nLEURIe0gtpvQJFghoLS4nnSBznqFxCR0XLgKKRE3fCdWzyCHIekMUpYH42A=w1280
 
ron said:
The image didn't come through, but what do you mean by distribution block? Can you just use a panelboard rated at 800A, 35kA SCCR?
Click to expand...
The panel will have a number of MSP + Contactors & VFDs etc. with a PLC controlling approximately 50 individual loads
So the 800 Amp in the MDP would feed these devices via a distribution block in this panel.
 
JoeStillman said:
Why don't people use MCC's for applications like this?
Click to expand...
Too much floor space and lack of flexibility in design and layout.
A motor control panel can easily be customized with factory installed and tested interwiring. Although a MCC can be sent to an integrator for customization, but then we go back to my first point.
 
I guess if you wanted to do it with a bunch of 10' taps on a common feeder, you can run the conductors in a wireway and splice along the run and pickoff power with C-type compression taps. You would have to be careful to balance the load from the paralleled source feeder conductors.
Then you wouldn't have to worry about SCCR of blocks.
 
Have you considered putting an 800A breaker in your control panel and then using a Power Distribution Lug for the breaker?
 
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