120/240V panel fed from a 208/120 source.

[electrofelon]

Thanks for the tip, but are you referring to a main breaker at the panelboard or just the individual breakers feeding branch circuits.

I think in the end I’ll have a 3 phase
disco(fused or with a breaker) and travel about a 100’ to the 3 phase panelboard which will either be an MLO or a 3 pole main breaker panel with individual single pole breakers feeding branch circuits.
Sorry for the confusion Electrofelon.

I was referring to the branch breakers, if you use "shared neutrals" or MWBC's then you need handle ties or three pole breakers

 

[Ozymandias]

Right, now I get it, no shared neutrals.

 

[petersonra]

Am I thinking correctly here?
If I have 80 refrigerators at 5 amps average for a total of 400 amps, divided by 3 phases to equal 133 amps per phase?
I’m trying to size the panel board,
Thank you all for the help.

pretty close. i would just get rid of the fused disconnect and put in a 3 phase MLO panel. the fuses will just be a pita at some point because they will open some night at 2 am when the fuse store is closed and everything in the fridges will spoil,.

 

[winnie]

Right, now I get it, no shared neutrals.

Actually I think Electrofelon is suggesting that you do share neutrals, but is noting that if you do so you will need to use handle ties or three pole breakers.

Using shared neutrals is a design decision.

Shared neutrals require simultaneous disconnection of all the 'hot' conductors sharing the neutral, which means that instead of shutting off 'one' circuit you have to shut of 'three'. Additionally if the neutral connection fails you can subject the loads to excessive voltage, causing damage.

However sharing neutrals comes with significant benefits as well: you use less materials at installation, and more importantly you use less energy over time because you have lower losses in the wiring.

I personally am a proponent of sharing neutrals. Remember that the feeder to the panel is itself a shared neutral circuit.

-Jon

 

[Ozymandias]

Actually I think Electrofelon is suggesting that you do share neutrals, but is noting that if you do so you will need to use handle ties or three pole breakers.

Using shared neutrals is a design decision.

Shared neutrals require simultaneous disconnection of all the 'hot' conductors sharing the neutral, which means that instead of shutting off 'one' circuit you have to shut of 'three'. Additionally if the neutral connection fails you can subject the loads to excessive voltage, causing damage.

However sharing neutrals comes with significant benefits as well: you use less materials at installation, and more importantly you use less energy over time because you have lower losses in the wiring.

I personally am a proponent of sharing neutrals. Remember that the feeder to the panel is itself a shared neutral circuit.

-Jon

Sold on MWBC’s. Will look out for Eaton BR as electrofelon suggested. Thanks!

 

[Ozymandias]

pretty close. i would just get rid of the fused disconnect and put in a 3 phase MLO panel. the fuses will just be a pita at some point because they will open some night at 2 am when the fuse store is closed and everything in the fridges will spoil,.

Maybe the employees’ lunch. It’s recovery management appliance store. Many of these units are in good condition except for missing a door handle or dented. By running them, they can find any issues and repair them. Too many returns because the freezer is faulty is costing them money.