A power panel to keep electrics safe and neat

There's lots and lots of individual electrical items in a grow op. Wiring must be kept off the floor and timers held securely in place where they can't be knocked out of a socket. High current devices like lighting and heaters must not be run on cheap power strips.

To avoid having a bunch of power strips daisychained all over the place as well as avoiding use of existing building wiring, which may or may not be gutsy enough to handle a grow op, build yourself a power panel with high-current capacity wiring and power outlet sockets.



This panel is made from the end of a discarded shipping container. It is a bit of plywood with some timber around the edges, along with a coat of white paint, both which keep the plywood from warping in the relatively humid environs of a grow op. If you build one, avoid MDF or particle board materials; they are not suitable for persistently 50-60% humidity environs and will go crumbly in a few months.

NOTE: This panel is built for 240V. See wiring detail for 120V (Nth America) growers.

This panel has 4 high quality surface mount outlets, each rated for 15A. Each 1000W light has its own HD outlet and timer. There's a couple of higher-quality power strips (those with switches for each outlet) permanently wired into the panel. There are some cheap power strips on this panel, but they are running only low current devices like circ fans and water pumps.

The panel has its own run of 30A @ 240V rated Romex cable to the breaker box. The wiring between the 4 HD sockets on the panel is all done in Romex as well.

Most importantly, the panel has its own circuit breaker, rated at 30A. The breaker also functions as a main switch to shut the whole grow op off in one click. 30A is a big breaker, but it will trip if something goes dead short.

I sleep pretty well at night while the ops is humming away flowering a bunch of plants, knowing that all the wiring for my op, from power outlets to the breaker box, is of known, top quality components and is in good condition. No electrical fires here, friends.

Nice one, Al. I always hang everything on the wall, and run all cords along the ceiling and walls. And make sure that everything is grounded. Is that an IR motion sensor there too? It's nice to have a security system.

That 10 gauge romex is a bitch to work with, but a must for a decent-sized grow.

Thanks a lot, Down There!

Thanks potroast.

No motion detector in the grow- but there's more than a few in other strategic places, along with some video cams.

Back to the panel- there's 2 mechanical timers in the top row, 1 digital for the water pumps in the 2nd and a pair of mechanicals doing nothing on a Y in the second row. The gray thing on the bottom left is a converted waterbed thermostat which runs the exhaust blower.

I elected to make up a panel as it was a lot easier to move and set up elsewhere if needed. Saves lots of time when setting up a new room. This panel is in its 5th grow op!

potroast said:

That 10 gauge romex is a bitch to work with, but a must for a decent-sized grow.

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You betcha. I built everything for 30A but the op draws a max of 14.2A with everything running.

Bless, bless, bless the wisdom of a 240V AC mains grid in this country. If this op were running on 120V, I wouldn't sleep well unless it had 2 runs of 10ga, cos it'd be within a gnat's eyelash of 30A.

All the HD sockets have compression screw connectors for a good mechanical connection to the 10ga, but I also filled and flowed those connectors with silver solder. Simply can't work loose and become resistive. The solder keeps the compression connections from oxidising or loosening, but isn't the main path for current.

Ok you started it, now finish it. What is the advantage of the 240 power to your panel? Is this the same power we call 220?
I can change mine over if there is a good reason, safety and saving money come to mind, in that order.
I installed a 200 amp main power box in my room and have the house power running from that main panel using a 100 amp breaker. I also moved my air conditioning circuit out of the house panel and wired it into the new service panel, and bought a gas stovr to replace the electric one. I have lots of room in that panel to wire anything I need to. I thought I had it set up right. I put four seperate 20 amp circuits down each side of the room. I have come to realize having all the plugs on the outside walls, behind the plants in not convinient to say the least, and have tried to think of how to change this once. Sound like you guys have one central power box and longer cords or wiring powering your rooms. Takes time for some of us to catch up I guess. VV

This is what I am about to install to run 4- 600 watt digital hps ballasts.

National Garden Wholesale - iLS4-120 Lighting Load Switch w Internal 0-20 Minute On Dela

This unit has an adjustable relay that will prevent hot starts after power failures, etc.

yes...sleeping well is important, AL! Good post. SAFETY FIRST!

good luck

bt dt

I wish I had the skill and knowledge to put that rig together!

VictorVIcious said:

Ok you started it, now finish it. What is the advantage of the 240 power to your panel? Is this the same power we call 220?

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The local AC mains voltage is 240V, just as yours in Nth America is 110-120V. All the wall sockets here are 240V. Our water heater runs on the same 240V.

You have 220V lines in Nth American homes because high power consumption devices are impractical to run on 110-120V. The copper wires required to carry high currents at low voltages have to be very thick. In example, an electric water heater will need about 9000 watts (9kW) of power. If you supply 9kW @ 120V, that's 75 amperes. That'd take a cable about 1/4-3/8" thick- times 3. The components within the water heater would also have to cope with the very high current. Thanks to Ohm's Law, we know that if you double the voltage up to 240, the current halves to a more manageable 37.5 amperes.

The standard line voltage in the USA varies from 110-120V but I've seen it in some localities as high as 127V. AC power is supplied to US homes as 220-240V but that is divided into 110-120V in the breaker box for wall outlets and lighting. The "220" lines provided for dryers, water heaters etc. are simply connected to the AC mains line drop connected to the house from the pole transformer, but before the voltage divider. The "220" lines in US houses usually are around 230-235V. You will only know what you have if you get a voltmeter and measure it.

I can change mine over if there is a good reason, safety and saving money come to mind, in that order.

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Depends on how much high power lighting you're using. Common household ckts in Nth American homes are 15 amps @ 120V. Ohm's Law sez that's 1800watts. A smart grower will only use 80% of the capacity for a continuous load- 1440W. If you need more than about 1500 watts for your op, you will need to shift some load onto another 120V ckt. You can do that with a heavy duty extension cord you can make out of HD home wiring components.

Now, if you're planning a big op from the outset, where you have several 1000W lights, it would be smart to pull in a new 220 line to the op and purchase all your lighting to suit 220.

However, if you buy 120V lighting when you start and you increase the size later on, you will still need to supply 120V but perhaps with an additional ckt and breaker in the box.

Some ballasts can be converted from 110-120 to 220-240. Your mileage may vary. Ask your ballast's manufacturer.

beenthere donethat said:

This unit has an adjustable relay that will prevent hot starts after power failures, etc.

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good stuff! Will save HID lighting from premature death. At $60-100 a pop for a 1000HPS, that's good insurance.

yes...sleeping well is important, AL! Good post. SAFETY FIRST!

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Thanks for that.

It's true, tho... you do see stories in the news from time to time about a fire which reveals a grow op. There's no reason in the world for this to happen to any grower... it's so preventable. You just have to know how much load you have and how much you can safely run on your ckts.

Use only the best quality connectors and assembly methods when doing any AC wiring. Anything less is false economy in the worst way. Can you imagine being the joker who went to jail for using cheapshit power connectors? If you can find hospital grade connectors at your local electrical supply house, buy 'em. Marked with a green dot and sometimes also 'hospital grade.' Probably 4x the cost of the usual, but hey...

Al, can the hospital grade plugs be purchased with the cord or must one wire them together?

Paola said:

I wish I had the skill and knowledge to put that rig together!

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If you can follow instructions, strip back wire insulation and can operate a cordless drill and a screwdriver, you can do this.

I can do up some much more specific instructions, but it's not much more complex than replacing a plug on the end of a common lamp's cord. You just duplicate that process a few times.

This power panel is nothing but a very fancy extension cord with some real heavy gauge residential wiring cable instead of lamp cord. If you can rewire a lamp, you can do this, too.

Al B. Fuct said:

If you can follow instructions, strip back wire insulation and can operate a cordless drill and a screwdriver, you can do this.

I can do up some much more specific instructions, but it's not much more complex than replacing a plug on the end of a common lamp's cord. You just duplicate that process a few times.

This power panel is nothing but a very fancy extension cord with some real heavy gauge residential wiring cable instead of lamp cord. If you can rewire a lamp, you can do this, too.

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As far as replacing the wall outlets would it be wise to replace them with hospital grade as well?

Paola, you'll buy the hospital grade connectors individually. All you need do is strip back the wires in the cable and attach them to the connector with their screw-compression fittings. Easy-peasy.

Al B. Fuct said:

Paola, you'll buy the hospital grade connectors individually. All you need do is strip back the wires in the cable and attach them to the connector with their screw-compression fittings. Easy-peasy.

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Right. I've also seen the HG wall outlets that you can use. Would those be a wise investment as well as the plugs?

Paola said:

As far as replacing the wall outlets would it be wise to replace them with hospital grade as well?

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Yes, very wise idea.

If any of the house wiring is in between the op and the fuse box, it pays to know a lot about the type and condition of that wiring. While house wiring will be sufficient in 99/100 cases, the only 100% sure thing is running your own Romex cable to the breaker box.

If some electrical evil happens on the 'other electrical side' of the breaker box, the fire point is both outside the house and is likely the power company's problem, not yours. As long as you're not drawing more than your installed service is designed to handle, all should be well.

You have the opportunity to overbuild the shit out of whatever wiring you use- the house builder might have been working to a price point.

wow good one ill have 2 make a simpler version

So when you get to your panel with the 240 volt circuit your are just splitting it for the smaller items, like pumps, fans etc. All of the wiring for my grow is 12 wire and all the breakers and receptacles are 20 amp. Each hid is on its own circuit and timer. The receptacles are all back wired like your talking about as hospital grade. Guess I just need to put more thought into how I can make it more convenient. VV

all is correct except the panel is only as good as the feed from the main breaker box and the breaker in there that feeds it, if your lucky you'll find 2 emty spaces in your maine box good place to tap some 220 voltage and the amps on breakers could be as high as you want as long as the subsequent wire guege is correct and the breakers you install are less amps than main breaker...but lets say that your panel is full and there are realy nothing you can tap into safely , does any one know a way to tap into main feed line between the meter and the panel (wouldnt want to steal juce) without breaking the seal on the meter? or any other alternatives...

krime13 said:

all is correct except the panel is only as good as the feed from the main breaker box and the breaker in there that feeds it,

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Which is why I said a few posts up the thread that if there's any existing house wiring between the grow and the panel, it pays to know a lot about the type and condition of that wiring.

does any one know a way to tap into main feed line between the meter and the panel (wouldnt want to steal juce) without breaking the seal on the meter? or any other alternatives...

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The hot lead from the meter will connect to the breaker panel's hot bus bar at some point for distribution to individual breakers. You can pick it up there without breaking the meter seal. However, you should put a breaker for your own line as physically close to the breaker box as possible, as the leads you run from the busbars to your op's Romex are only protected by the main cartridge fuse or main breaker. The likelihood of a short ckt in between your breaker and the busbars is fairly low, but you should take steps to protect that small run of Romex anyway.

edit: Incidentally, my local convention is to fuse or breaker the hot/line/active lead only. You could (and probably should) use a ganged breaker (basically 2 breakers with one handle lever) which can also manually switch or protect the neutral (blue) portion of the circuit as well. This would allow you to safely de-energise all parts of the panel by throwing a single ganged breaker lever.

krime13 said:

(wouldnt want to steal juce)

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Too right!

Bridging out a power meter is both patently unsafe and a very rapid way to detection.

If a power company's billing records indicate a subscriber's meter isn't spinning, they will send out a technician with a new meter. When that meter doesn't spin, the techie will put an amprobe around one of the leads in the drop from the pole to see if there's current flowing. If there's current flow and yet no meter spin, the techie goes looking for why that might be.

I disagree with laws on cannabis cultivation and am working on pressuring government to change those bad laws. However, I've got no beef with theft laws nor the power company and am happy to pay for my power usage, on time and in full. Stealing power is dangerously stupid on a number of counts.