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We are currently working on the buildout for our distillery and have come across a number of questions/issues regarding whether we need NEMA 7 enclosures on our electric elements.

Anyone have any experience with this? I know, I know Im sure some answers will be consult your architect/engineer etc. But I have heavily consulted DISCUS, NFPA, NEC, IBC, IFC etc and our professionals, the question is really what have been other's experiences as far as what was required when running electric elements.

FYI, we have three phase power and are planning to run one 18-20 KW and two 6 kw in each pot.


Ryan Vierheller

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I does not matter what anyone here says. Your local building inspector and fire marshal will play "GOD" over you.

I would normally put down the code, but the code is the minimum requirement. The local and state authorities can demand more than what is required in the book.

I am willing to bet that not one person will disagree with me.

Before you do anything you should check with your local or state authorities to see what they want because the worst case scenario is you do your build out and then you have to rip it all out and do it over.

Best of luck to you!

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Dehner is spot on, the local inspector will have final say.

Note that they could require a higher or lower standard as compared to code.

Also, there are a lot of variables such as air exchanges that will effect how an area is classified if you end up in a code case.

Get cozy with your local code people; the more comfortable they are with you and your project the better for your wallet.

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  • 2 weeks later...

Ryan -

We ran into similar issues, and as Dehner and Equinox suggested, we had to get very comfortable with our local electrical inspector (who is a bit difficult to work with AND hasn't had to deal with this type of industry ever before). In the end, prior to installing anything, the inspector requested a formal code review and engineers stamp by an outside agency (which cost around $1500). It was expensive, but once we had that in hand the inspector backed off (for now, we still need our final electrical inspection). Our requirements did include localized areas of the plant that are Class 1 - Div 1 and 2 and needed XP / NEMA 7 motors, enclosures and conduit.

The codes referenced in our review were NFPA and Massachusetts state building code (MSBC), which is built off national el. code (NEC).

This was in MA, so all requirements and inspections fall on local municipal government - the state gov stays out of the process. Other states may require approval at state/county and municipal level - but your local inspector should be able to tell you that.

ALSO keep in mind, as mentioned above, these are minimum requirements - I would highly recommend going the extra mile to keep yourself safe and the inspector comfortable. We installed an additional environmental hydrocarbon sniffer, over sized ventilation fan and a number of process monitoring devices that have built in fail-safes should any of our equipment malfunction. Small price to pay for a much larger piece of mind.

Good luck!

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Equinox mentioned "air exchange"

The authorities here in Tasmania were coming down hard on a couple of new small distilleries, trying to make them put in very expensive safety devices to eliminate ignition sources.

Then a smart electrical contractor read further into the regs and found that if air exchange was over a certain rate then this part of the regs did not apply. He had to install forced ventilation with sensors back to main switchboard that would turn off still etc if the ventilation was not working. A lot cheaper option.

I know regulations are different everywhere but it might be worth asking if ventilation is an option.

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Our still (and surrounding area) is Class I Division 1 Group D by our own decision. Agitator motor is explosion proof, rigid conduit, sealing glands, etc etc. We removed all other extraneous electrical from the area. However, with regards to NEMA 7 enclosures, we found it more cost effective and realistic to move controls and other electrics outside of the classified area (rigid conduit is cheaper than enclosures). For example, the VFD for the still agitator is outside of the classified area in a standard metal enclosure. Key thing to realize is that removing non-essential wiring, fixtures, plugs, etc is going to be significantly more cost effective than trying to replace them with their classified counterparts. Things like RTD temperature sensors and pressures sensors are also classified or in classified enclosures, along with intrinsic barriers at the controllers. We've got combustible gas monitors with interlocks to shut down everything but the condenser water flow.

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