Electric Boiler Disconnect

[Npstewart]

Im adding a 240 kW electric boiler to an independent of the existing electric service. This will be fed from the transformer, to an exterior 700A fused disconnect, and then to an electric boiler located inside the building.

Having an interior non-fused disconnect for service may be an issue due to space because it will be rated for 800A. Anyone see any issue with requiring the exterior disconnect to be lockable in the open position and then providing signage at the boiler notating its power source to eliminate the requirement for an additional disconnect at the boiler itself?

I was thinking of adding a shunt trip inside but this may get expensive.

PS> No, a gas boiler is not an option

 

[kwired]

Disconnect not within sight should be acceptable if lockable.

Is your second service disconnecting means grouped with the other service disconnecting means?

 

[Npstewart]

Disconnect not within sight should be acceptable if lockable.

Is your second service disconnecting means grouped with the other service disconnecting means?

Perfect, just wanted confirmation. Yes, both disconnects are side by side with independent runs to the transformer.

 

[Ingenieur]

Shunt trip expensive?
what part of the country is this going?
elec bill may 20K/yr
use propane until ng available?

800,000 btu boiler

 

[kwired]

Shunt trip may still be a consideration if you need to have a EPO near the boiler.

 

[Npstewart]

Shunt trip expensive?
what part of the country is this going?
elec bill may 20K/yr
use propane until ng available?

800,000 btu boiler

Natural gas is available but appearently a gas fired boiler requires the building to be modified to house a gas fired boiler. Appearently this boiler is only used 3 hours a week to create steam used for brewing processes.

 

[Npstewart]

I was planning on using a fused disconnect. I know there is a shunt trip fused disconnect but not sure how common they are?

 

[augie47]

You also might want to look a Art 424, likely Part VII, to make sure you have all those bases covered.

 

[Npstewart]

You also might want to look a Art 424, likely Part VII, to make sure you have all those bases covered.

Will do, thanks.

I wonder if I have to take this at 125%? That would put me at a 1000A rated disconnect. It's not continuous but I think it may qualify as a storage heater but not sure of the storage capacity.