Growroom Electricity and Wiring

[Justsilent]

Just talked to my building dept. anything that isn't a 120 v outlet or switch has to be done by licensed electrician. Think that is not right. Don't take too many brains to run a wire and put a wire to a b wire to b and c wire to c. O well. I guess that's why people break the law. Going to splice and run new line to room and plug in there.

 

[Justsilent]

A few more questions to u rives.
I couldn't find a 30 amp pannel with 4 slots ( to allow me to run 2 15 amp circuits) so the nearest one I could with 4 slots was a 100amp. I wired everything already but I ran into a possible problem. The dryer cord that I purchased was a 10 gauge 3 prong dryer outlet but the main lugs on pannel say they recommend 8 gauge wire to 1 gauge. When I tightened the cord feeding the pannel the lugs smash the wire. It's stranded wire. It holds good though but not sure if that is the way to go about it or if there's a better way

Question 2 is being that my panel is 30amp 240v panel I do need to bond neutral bar to box. Correct? This is the only bar in the pannel but came with a green bonding screw.

Last question is I bought 6-20r outlets and housed them in a metal outlet box. Do I need to ground anything to that metal box? as I will do with the junction box that ( light box) is going to house the relay to power on an off my lighting that I wired a copper wire to box with a green screw and I'm going to pig tail that with the ground coming in from circuit and the ones going out to my 240 v outlet and all grounds go together correct? Even the one feeding the 120v timer to light box?

Once again thank u for all your help. Couldn't have done this without u and this forum.

 

[rives]

It would be best if you could find the correct lugs for the size wire that you are using - too large of a lug will not usually clamp the wire adequately. An electrical supply house might have a broader selection. The lug can be changed out by removing the set screw that holds the wire and inserting an allen wrench through the hole. Make sure that the new lugs are torqued down properly when you change them out.

Sub-panels do not have the neutral bonded to the enclosure. They should only be bonded together at the main panel. You can also purchase a second buss at the supply house. If the ground and the neutral are tied at a remote location, it can cause ground loops which will screw with any sensitive electronics, particularly sound systems.

All of your metal boxes should be bonded together with a ground wire. There will usually be a raised boss inside them in the back for that purpose, and they make short bonding jumpers that are green with a ring terminal on one end for making the connection to the box. If you use metal offset nipples between the boxes and an listed grounding lock rings, then you don't need to wire them all together, but it is usually easier and safer in the long run to use the wire method. Oh, the ground wire should either be bare or green - if you use a different colored wire to do it with, you can purchase green "phase tape" to mark it with.

Glad to be of help!

 

[Justsilent]

Even though there's no neutral wires at all in this panel? Incoming feed is 2 hot one ground outgoing is the same. Just dividing one 30 amp circuit into 2 15 amp circuits. I can't find any lugs to replace online. Not even one. So as far as the grounding I ground everything together to the ground wire coming from the breaker ( from subpanel) so that ground would be connected to the relay to the metal junction box then out to 6-20r outlet then to metal outlet box? Can u post a link to any main lug reacement for putting 10 gauge wire in a 100 amp panel

 

[rives]

I'd forgotten that you hadn't carried a neutral in this case. Your existing bar can be used for the ground, and bonded to the enclosure with the provided jumper.

Yes, all of the ground wires are tied together.

The lugs are going to be different from manufacturer to manufacturer. You would need to go to their web site with the make/model of the panel that you are using and see what alternate lugs they have listed, or call a supply house with the information and ask them what the options are.

 

[Justsilent]

They are fixed main lugs. Can't be swapped. I spent 40 on this panel and opened two of the holes for wires so can't return. Do I have any other options?

 

[rives]

None that are code compliant. You could possibly double the length of the stripped portion of the wire, fold it in half, and tighten the lug down on it. It might work better if you could tin the wires with a soldering gun after folding them over, so that they would become like a single-conductor wire. If you try the soldering method, make sure to use rosin-core solder and not acid-cord. Acid-core is only to be used on plumbing applications, and will continue to erode the wire away over time.

 

[Justsilent]

Is what I'm trying to do is possible taking one 240v 30 amp circuit and disposing it into 2 240v 15 amp circuits then why don't they make a four space 30 amp box so it would fit 2 15 amp double pole breakers? At least square d doesnt

 

[RM - aquagrower]

Hey ya'll. Wanted to take a moment to thank all who have contrubited to this thread. Probably saved countless folks from burning their houses down.

Now I have a question.

I have a 200a service w/ a square d QO loadcenter w/ plenty of empty space. I also have 2 intermatic timers. 1 t101 and 1 t103. I am setting up 2 6x6 flower areas w/ 3 600w lumateks in each. I have 6 ballasts so no need for a flip box.

I would like to pop this breaker into the loadcenter http://www.homedepot.com/Square-D-b...3&langId=-1&keyword=20a+breaker&storeId=10051 and run 12-3 to a junction box.

Inside the J box I would attach to 2 12-2s, with each 12-2 sharing the neutral on the 12-3. Each 12-2 goes to it's own timer. Terminals 3 and 4 on the t103 would be left empty.

If I've properly understood MP's posts on MWBCs, this is a sound plan, and should give me 20a to each timer. 3 600's should be pulling 15a (16 allowed). I have enough other power in the rooms for fans/pumps, just want the new power for the lighting.

So sparkys, what say ya'll? Sound plan, or back to the drawing board?

Thanks again!

 

[rives]

Justsilent - I believe that GE makes exactly what you are talking about, as well as a load center that will accept (3) double-pole breakers.


RM - I'm not understanding why you want to use the double-pole breaker. It is not unusual to interlock two 120v breakers together, so that if there are two circuits that must work together and one trips, it takes the other out with it. This is essentially what the double-pole breaker would be doing in your case, but I don't see why you would want to shut both rooms down if one had a problem.

The bigger problem that I see is splitting the neutral - this is questionable practice under most conditions, and a really poor idea when you know that the circuits are running heavily loaded. The neutral wire is carrying the same load as the hot - AC power alternates polarity 60 times per second (60 hz), so the neutral wire sees the same current as the wire that you normally think of as "supplying" the current. I'd just run (2) 12/3's back to the panel, and probably use single-pole breakers unless there was a reason that I wanted to dump both rooms if one had a fault.

I'm not picking up on your reference to MP & MWBC's, though. Maybe I'm missing something.

 

[RM - aquagrower]

Thanks so much for advising me on this. I read this entire thread about a year ago, and have followed is loosly since.

I got the idea from post #330 in this thread. MP wrote:

If your just going to ditch the subpanel and do one homerun out of the main panel, and you have the extra money to buy 12/3 and not just 12/2, It might be worth your while to buy a roll of 12/3 romex and a double pole 20A breaker. Hook both the red and black wires up to the double pole 20A breaker and then run the 12/3 all the way to your grow room.

If you have an accessible attic above your grow room, then run the 12/3 into a junction box. Cap the red wire, and then splice 12/2 onto the remaining wires for your new 20A circuit.

If, in the future, you find out you need more power, you have 20 more amps on that red wire in the junction box right next to your grow room just waiting to be used.

In that case, you'd tie the new 12/2 black onto the 12/3 red and then splice/wirenut the neutral and grounds together with the other previous 12/2.

If it's a bad idea, I will gladly ditch the plan and run a 12-2 20a to each room. I was just trying to get away with only running 1 cable accross the basement.

Thanks again! K+ to ya

 

[rives]

Okay, I just went back and read that post and a number prior to that. MadPenguin and I do not agree on the theory behind the use of a multi-wire branch circuit. His premise is that since you are feeding out of the panel with 240v, the neutral is only carrying the load imbalance between the two hot legs. As I said before, there is no difference between (2) single-pole breakers on alternate phases, or (1) double-pole breaker feeding (2) 120v circuits. The neutral is center-tapped on the transformer, so that wire is the only path back to the power source to complete the circuit for a 120v load - the other hot lead is totally irrelevant to the circuit.

 

[RM - aquagrower]

Okay, I just went back and read that post and a number prior to that. MadPenguin and I do not agree on the theory behind the use of a multi-wire branch circuit. His premise is that since you are feeding out of the panel with 240v, the neutral is only carrying the load imbalance between the two hot legs. As I said before, there is no difference between (2) single-pole breakers on alternate phases, or (1) double-pole breaker feeding (2) 120v circuits. The neutral is center-tapped on the transformer, so that wire is the only path back to the power source to complete the circuit for a 120v load - the other hot lead is totally irrelevant to the circuit.

Cool. You da man. 1 20a per timer it is. Not a real cost difference between the 2, as a 100' roll of 12-2 is about the same as a 50' roll of 12-3.

Theoretically, the MWBC would work, as along as both rooms weren't lit at the same time. Then the neutral would only see 15a at any given time.

But then I would loose the option of ever vegging in one of the rooms, which is one of the reasons I sprung for the other 3 ballasts, instead of building a flip box.

One more question, if it ain't too much trouble. As stated above, I have a t101 (spst) and a t103 (dpst). When I bought them (used), I thought that they were the same, didn't notice the difference 'till yesterday. Exactly what is the advantage of the dpst? In reading this thread, it looks like they can both be wired the same (leaving terminals #3 and #4 empty on the T103). In my application, they will be doing the same thing, so it ain't a big deal, just wondering.

Thanks again.

 

[rives]

The dpst (double-pole, single-throw) contacts are for a 240v load. If you are switching 240v, both hot legs are supposed to be broken simultaneously. It could also be used for two separate 120v circuits that worked in unison.

 

[RM - aquagrower]

Ahh, I get it.

So, if I wanted at a later time, I could knock out the wall seperating my to rooms, run both 20a 120v circuits to the one timer (t103), and control all 6 ballasts from the 1 timer.

Thanks again, you are a real asset to the community!

 

[draztik]

I have a quick question for anyone that can help. I need to power a 1000 watt ballast @ 220V. The ballast is rated @ 4.3 Amps. I don't have room for another breaker and all other power sources are used. Would it be possible to tap off of my dryer outlet to power the ballast? My idea was to run a 12-2 splice from the outlet to a custom light controller that would be mounted on the wall. Is this possible or is this a bad idea?

 

[rives]

It would be a bad idea. Your dryer outlet is probably fed with 30 amps and 12/2 is rated for 20. You could pick up a dryer cord at Home Depot or the equivalent and use it to feed the lighting controller, but there should still be some intermediate protection between the dryer cord and the lighting circuit. If the controller doesn't have some breakers/fuses for that purpose, a small sub-panel could be used.

 

[draztik]

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[rives]

You can buy circuit breakers that mount on DIN rail, but by the time you get done with it, it would be cheaper to buy one of the small sub-panels from the Depot or Lowes. GE makes some that have space for 4-6 single pole breakers that are around $20 (without the breaker cost figured in). That relay is fine, I use very similar ones from either Grainger or AutomationDirect for the same purpose. That tutorial is a good one, it just doesn't protect the lighter-rated components adequately.

*edit* Much better price on the relay here, they have a SPDT one that is a couple of dollars cheaper but less versatile - http://www.automationdirect.com/adc...n-Style,_40A_(AD-PR40_Series)/AD-PR40-2C-120A

I've also picked them up on eBay for a fraction of retail price.

 

[draztik]

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