Time clock controlled outlets in pot growing operation

[electrofelon]

Ive been doing some work in a medical marijuana growing operation and most of the rooms need to be time clock controlled. All light are cord and plug connected and have 20A 250v plugs. There is a variety of methods employed there to accomplish this by the previous electrician that was in there, including a contactor controlled by a programmable wall timer, a time clock on the line side of a subpanel, and time clock fed by a branch circuit then feeding some outlets. Each room takes 30-40 amps at 208 single phase, but due to the loads being continuous and providing for expansion, 60 amps would be nice, so the 40 amp rating of the time clock is a bit of a problem. I will be doing another grow show next week and am trying to come up with the most economical and uniform way to do this which led me to this idea and question: Is there any code issue with using a time clock to switch one leg of a feeder that then feeds a sub panel that feeds 250 volt outlets? If this is ok code wise my plan is to run two #10 feeders (single phase 208v no neutral) to a DP time clock where one leg of each feeder will be switched and then each feeder will hit a small panel with 2 20 amp breakers and two 20A 250v receps. This would get me 60 amps total with a minimal material bill, minimal install time, and the convenience of one time control. I couldnt find a violation but it does seem odd to me for some reason, even though it is done with electric heaters a lot, but here I have receps......
Thanks

 

[480sparky]

Use the time clock to run the coil of a contacter.

 

[GoldDigger]

Use the time clock to run the coil of a contacter.

Using the time clock to switch just one of the two ungrounded conductors that will end up at the load means for sure that the time clock cannot be used as a disconnect. But for luminaires supplied by two ungrounded conductors does every switch along the whole supply path have to switch both conductors or just any switch which is part of the luminaire? (Article 410) If there is a two-pole handle tied or simultaneous trip breaker in the sub-panel after the time clock, does that change the answer in any way?

 

[jusme123]

Ive been doing some work in a medical marijuana growing operation and most of the rooms need to be time clock controlled. All light are cord and plug connected and have 20A 250v plugs. There is a variety of methods employed there to accomplish this by the previous electrician that was in there, including a contactor controlled by a programmable wall timer, a time clock on the line side of a subpanel, and time clock fed by a branch circuit then feeding some outlets. Each room takes 30-40 amps at 208 single phase, but due to the loads being continuous and providing for expansion, 60 amps would be nice, so the 40 amp rating of the time clock is a bit of a problem. I will be doing another grow show next week and am trying to come up with the most economical and uniform way to do this which led me to this idea and question: Is there any code issue with using a time clock to switch one leg of a feeder that then feeds a sub panel that feeds 250 volt outlets? If this is ok code wise my plan is to run two #10 feeders (single phase 208v no neutral) to a DP time clock where one leg of each feeder will be switched and then each feeder will hit a small panel with 2 20 amp breakers and two 20A 250v receps. This would get me 60 amps total with a minimal material bill, minimal install time, and the convenience of one time control. I couldnt find a violation but it does seem odd to me for some reason, even though it is done with electric heaters a lot, but here I have receps......
Thanks

Is that your disclaimer? :jawdrop::lol:

 

[GoldDigger]

Is that your disclaimer? :jawdrop::lol:

Although in his state it may not even be an electromisdemeanor, it is probably still a Federal offense.

 

[electrofelon]

What I am asking is: Does the NEC apply to illegal activities? Totally kidding, and actually this is in the state of Washington where it is mostly legal - some gray areas with quantity but basically legal as long as the feds dont get involved.

Using the time clock to switch just one of the two ungrounded conductors that will end up at the load means for sure that the time clock cannot be used as a disconnect. But for luminaires supplied by two ungrounded conductors does every switch along the whole supply path have to switch both conductors or just any switch which is part of the luminaire? (Article 410) If there is a two-pole handle tied or simultaneous trip breaker in the sub-panel after the time clock, does that change the answer in any way?

I thought about the disconnect issue, but cant see that that would matter since for one I dont even see a requirement for a disconnect and besides I have the cord and plug and the circuit breakers right there. Even if it is not a code issue, I admit it is not the best design since there would still be a live ungrounded conductor to all the lights the whole time. Using a contactor is certainly an option, just weighing all my options for economics and regardless it is a good code question.....

 

[Little Bill]

Try a little of the product and your thinking will become much clearer on this!

But have some Cheetos and Little Debbies close by after your done "thinking"!:lol:

 

[newservice]

how do the feds not get involved? I thought it was the National Electridc code.

 

[tallgirl]

how do the feds not get involved? I thought it was the National Electridc code.

The DEA isn't the NFPA.

Yet.

I agree with using the clock to control a contactor. I don't know of any web-based relay controllers that also include time clocks (since I drive them from software that has a clock ...), but that would be another alternative since it would allow someone to see what is going on.

 

[mivey]

since it would allow someone to see what is going on.

might the the last thing you would want in this type operation.

 

[tallgirl]

might the the last thing you would want in this type operation.

Only when the reddest of the red states finally legalizes pot will this sort of joke FINALLY die.

OBTopical -- as these sorts of operations become larger, better control will become important, which is why I think remotely viewable controls is the way to go. Of course, eventually people will grow the stuff in fields like every other commercially grown plant and a certain class of electrician will be very sad ...

 

[mivey]

Only when the reddest of the red states finally legalizes pot will this sort of joke FINALLY die.

and when it is no longer against federal law. Pot is still a Schedule I drug under the CSA.

which is why I think remotely viewable controls is the way to go.

It might not be the smartest thing to have remote access to an operation that is in violation of federal law.

 

[K8MHZ]

Remember my post about the receptacle that would accept both 120 and 240 volt receptacles?

That receptacle was from one of those 'horticultural' lighting controllers.

I have seen a set up that used a real industrial timer to control receptacles. The timer was next to the breaker panel and the grow room was on a different level and a different side of the building.

I didn't examine it thoroughly, but it looked code compliant to me.

Grow rooms are going to be cropping up all over. Michigan is now a 'medical marijuana' state. I have kind of been letting others test the waters. I don't know of a single grow room in my area that has been host to any type of electrical inspection.
Some things to consider:

In a dwelling, 240 volt lighting is not allowed.

What type of location is the room? Dry, damp or wet? Are any of the chemicals used to grow the product considered hazardous? What of the product itself and its by products?

There are new companies that make lighting controls and timers. Stay away from them. Use tried and true (like Intermatic) timers and (Seimens) contactors. I just mentioned those two brands as examples.

If you have doubt about NEC compliance, why not get the supposedly legal operation inspected when you are done?

I have yet to hear of what an electrical inspector has to say about a grow light operation so I am kind of curious.

 

[K8MHZ]

More curiousity:

Would a grow room fall under Article 547 - Agricultural Buildings?

 

[iwire]

Just a heads up from a moderator here, please stay on the electrical issues here and leave the comments about the product being grown to another forum.

 

[growler]

More curiousity:

Would a grow room fall under Article 547 - Agricultural Buildings?

Why not? There are no code sections for pot growing operations because pot is just another plant.


If I get involved in a project like this it is not my concern what they are going to grow but to do a legal job (code compliant ). If necessary (required ) and the city or county will issue a permit for the work then it's up to them to make sure the business is legal.

I wouldn't use any words suggesting the true intended used of the electrical system.

 

[K8MHZ]

Why not? There are no code sections for pot growing operations because pot is just another plant.


If I get involved in a project like this it is not my concern what they are going to grow but to do a legal job (code compliant ). If necessary (required ) and the city or county will issue a permit for the work then it's up to them to make sure the business is legal.

I wouldn't use any words suggesting the true intended used of the electrical system.

I would have to say 547 would apply, too. That includes wiring methods and mounting. "All cables shall be secured within 200 mm (8 inches) of each cabinet, box or fitting" is just one interesting note.

 

[iwire]

All light are cord and plug connected and have 20A 250v plugs.

<snip>

Is there any code issue with using a time clock to switch one leg of a feeder that then feeds a sub panel that feeds 250 volt outlets?

You did not say but I assume the lighting is HID?

If so it is a violation to control it with just one leg.

410.104 Electric-Discharge Lamp Auxiliary Equipment.



(B) Switching. Where supplied by the ungrounded conductors
of a circuit, the switching device of auxiliary equipment
shall simultaneously disconnect all conductors.

Considering that properly controlled lighting has a direct impact on production I would think they should be willing to pay for doing a nice job.

 

[iwire]

I do not see 547 applying here.

547.1 Scope. The provisions of this article shall apply to
the following agricultural buildings or that part of a building
or adjacent areas of similar or like nature as specified in
547.1(A) or (B).

(A) Excessive Dust and Dust with Water. Agricultural
buildings where excessive dust and dust with water may
accumulate, including all areas of poultry, livestock, and
fish confinement systems, where litter dust or feed dust,
including mineral feed particles, may accumulate.

(B) Corrosive Atmosphere. Agricultural buildings where
a corrosive atmosphere exists. Such buildings include areas
where the following conditions exist:

(1) Poultry and animal excrement may cause corrosive
vapors.

(2) Corrosive particles may combine with water.

(3) The area is damp and wet by reason of periodic
washing for cleaning and sanitizing with water and
cleansing agents.

(4) Similar conditions exist

 

[jim dungar]

You did not say but I assume the lighting is HID?

If so it is a violation to control it with just one leg.

That code section is about a switch acting as a disconnect, not about one acting as a controller.