Experienced Electrician! Here to Answer Any and All Growroom Electrical Questions

dragun said:

a lot of houses have a 200 amp electrical boxs these days.can the main wire to my house handle an extra 200 amp box.for a total of 400 amps.

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Speaking of sub-panels lol. The answer is no you can only use 50% of the total amps from your main panel. So if you have a 200 amp service you can have a 100 amp sub-panel. Why on earth do you need so much power anyway? lol Most homes these days are fine with just 100 amp service (unless you have a pool or spa). We forget how efficient devices are becoming as technology advances.

Wolfrick said:

Speaking of sub-panels lol. The answer is no you can only use 50% of the total amps from your main panel. So if you have a 200 amp service you can have a 100 amp sub-panel. Why on earth do you need so much power anyway? lol Most homes these days are fine with just 100 amp service (unless you have a pool or spa). We forget how efficient devices are becoming as technology advances.

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The on demand electric hot water heaters, from what I remember, can draw upwards of 50-75 amps. Electric stove/range, heat, central AC, hot water add up.
(though not sure why one would go electric on demand hot water)

Sure more and more devices are getting efficient, but there are more and more devices coming out. Look at kitchens. 50 years ago, just a couple outlets was fine. Now its nearly every 2 feet.

But currently, yeah 100-150 should be fine for most homes of normal size.

dragun said:

a lot of houses have a 200 amp electrical boxs these days.can the main wire to my house handle an extra 200 amp box.for a total of 400 amps.

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Not all builders are willing to pay the extra money for a 200 amp service on a spec house.
If your home came with a 200 amp service all the conductors are sized for the rated size and not higher in the last few years the price of copper andd aluminum has gone way up.
I've been told that is due to a building boom in either Japan or China they're building these mega structures also the price of steel has gone up alot as well.
We're fead so much garbage to explain rising costs I don't know what to belileve anymore.
But one thing holds true homes are built to the letter of the code but remember the code is the bare minimum so translated they're built to the lowest possible standards allowed by law.
So when a contracter tells you all his work is up to code what he's really saying it was the least he could do and still get away with it.
One thing you may notice if you have an electrical service that comes in overhead from a pole is that the wire looks and is smaller than the wire coming in after the electrical meter to the main breaker the utility companies have different insulators on their wire and can reduce the wire size accordingly also they get to reduce wire size based on conductors in free air space meaning if the wire is ran outside any pipe or other enclosure they can rely on air flow to keep the wires cool.
And they are not held to the same codes as home owners, you might have noticed that there is no overload protection on that wiring before it hits your house in fact the main breaker is your first line of defense so to speak.
So if two live wires hit each other before the main breaker there is no protection, kind of scary.

BigBudBalls said:

The on demand electric hot water heaters, from what I remember, can draw upwards of 50-75 amps. Electric stove/range, heat, central AC, hot water add up.
(though not sure why one would go electric on demand hot water)

Sure more and more devices are getting efficient, but there are more and more devices coming out. Look at kitchens. 50 years ago, just a couple outlets was fine. Now its nearly every 2 feet.

But currently, yeah 100-150 should be fine for most homes of normal size.

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You have to concider the fact that with one of these units your only paying to heat the water your using now not the water your using later in a regular hot water heater you pay to heat the water till you use it and to maintain the water temp for later, so an on-demand heater is in some ways more efficient also next time your at a home center just try to find an energy star rated hot water heater.
They don't exist.
And yes they do draw alot but only when you are running hot water.

Wolfrick said:

I'm also an electrician by trade, and I was wondering if you could elaborate on the reasoning behind splitting grounds and neutrals in a sub-panel. As I'm sure you know, at the main it is not necessary by US code so why is it on the sub?

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I've asked the same question and have never gotten an answer that made sense.
But have you ever noticed that you get seperate neutral bars and seperate ground bars in main breaker panel but you have to buy a seperate ground bar for the sub panel when it is mandatory to have one in the first place.
So many things make no sense to me all I can chalk it up to is that it is just another way to get us to pay more for material.
The only answers I've ever been given is that it is for safety reasons and that it is the code and that came directly from an inspector.
Go figure..

AquafinaOrbit said:

CFLs use just as much wattage per lumens as HPS and MH and infact use more. So for a comparable grow lumens wise you would pay more to run CFLs then an HID. Saying CFLs are cheaper in that regard is about the same as saying incandescent light is cheaper then a CFL. (Not as extreme of course) Also even in alaska a 400Watt 12/12 cycle would not pull 138$ in a month. That 138$ is probably his entire bill or he has AC going. (12/12 in NC at 10cents a kilowatt hour (Its rated lower but after taxes) is about 25 bucks using a 600 watt)

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His bill might have reflected additional electric needed to compensate for the higher temps created by the HPS and having to run the airconditioning more.
I live in an area where we're all electric some tree huggers got together a long time ago and blocked gas lines from being ran through the forests that surround my town and the homeowners association doesn't allow LPG either so we heat by electric also hot water, I would welcome a $138.00 electric bill I'd kiss the meter reader on the lips for one of those and I'm a manly man darnit.
So for me CFL's are it ,anyone know where i can get a wind up toaster......
Honestly I cringe when I see the electric bill.

I took this table from a CFL tutorial.
to give you an Idea of how different light sources put out light.
You'll notice that HPS and MH seem to out perform CFL's but keep in mind that you get some additional flexability from CFL's you can hang them closer to and in between plants directing the light more efficiently.
I'm sure each of us has our own opinions on lighting and I've seen some spirited arguments on here over it, but at the end of the day all of us are going to do what works best for us and fits into our budgets.
I may one day go out and buy an HPS fixture to see what difference if any it makes to me.
In my own home I've gone around and have replaced almost all of my regular bulbs with CFL's in order to save money in the long run when CFL's first came out I hated the color of the light but they've done a much better job and have lowered the prices for the bulbs as well, you can run 3- 60 watt CFL's to 1 incandescant bulb that appeals to the tightwad in me.
If your interested in reading the CFL tutorial just hit the link below.
https://www.rollitup.org/cfl-growing/202718-cfl-tutorial.html
I know this is not a CFL thread but it is a resource at your disposal and I thought it might be informative to those still on the fence.
No matter what your lighting choice is try to enjoy your growing experience and kiss your dealer goodbye.
you can allways send him a Christmas card. Lol


Approximate light production:
Incandescents: 17 lumens/watt
Mercury vapor: 45-50 lumens/watt
Fluorescents: 60-70 lumens/watt
Metal halide: 90 lumens/watt
High pressure sodium: 107 lumens/watt

If your talking to me Karloff my grow rooms been CFL for over a year now, just stating that HPS/MH is a more efficient technology. As for the bill, I live by myself with no AC, using propane range and water heater and my bill was over 200$ last month though it's usually more like 130. (Oh and my grow room is only pulling about 500watts right now, 400+ in CFLs and about 80 in fans.) Again just stating that there is a basic easy way to figure out a bill and 138$ from 400watts is not happening.
I agree on service load size though, and yeah even though appliances may be more efficient then ever we are still as a whole drawing more power then ever. Hell originally a house would have a single light and a receptical which they could connect an ice box to. Today though, out of 100Amps if you had two general appliance circuits which you would, 40amps would already be dedicated to that, then 20 more amps for a laundry circuit, and what 3 watts per sq/ft of general lighting. Of course those would never pull full load all at once, but on the otherside you'd never run an electrical dryer on 20amps and your looking at 50+amps for a range. (I'm running a 200A 40 slot panel board but it's a bit overkill, 100Amp would run me but would be about maxed)

Karloff said:

You have to concider the fact that with one of these units your only paying to heat the water your using now not the water your using later in a regular hot water heater you pay to heat the water till you use it and to maintain the water temp for later, so an on-demand heater is in some ways more efficient also next time your at a home center just try to find an energy star rated hot water heater.
They don't exist.
And yes they do draw alot but only when you are running hot water.

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All true, but at any given time everything *could* be on. (granted not heat and AC)

So if I read you right, no prob with having say a 75 amp sub panel with 200 amps worth of breakers in it?
(I use 200 figuring 75 per leg would be 150 to single pole breakers)

I have a relatively small two tent veg(2-2ft, 4bulb T5s)/flower(250watt HPS) setup in my home office. Using my Kill-a-watt, I've determined that I'm pulling ~ 4amps for lights and fans (soil grow, so that's it).

However, since it's a home office and I work from home frequently in addition to being a huge computer geek, I have multiple (4-5) computers running 24x7, pulling around 1.5amps a piece. Also, I live in the desert where it frequently hits 115 in the summer. Since I need to keep the door closed for both work and grow reasons, the room gets crazy hot during the summer. To combat this, I also have a portable A/C unit in the room.

I have to plug the A/C into an extension cord into the next room or I trip the breaker. Also, I had to move my wife's treadmill into the guest bedroom. I'm looking to rectify this.

I'm thinking that what I need to do is have an electrician out to run a dedicated circuit (thinking 20amp to account for possible expansion?) to plug either my grow setup or computers into and the A/C or Treadmill into. Right?

Here are pics of my breaker box. Can anyone give me a rough estimate of how much it might cost to have an extra circuit added to the box and run to my grow room/office? It's on the opposite side of the house from the box, but it's a 1-story 2300 sq foot house, so it's not terribly far.

Thanks,
DB

AquafinaOrbit said:

If your talking to me Karloff my grow rooms been CFL for over a year now, just stating that HPS/MH is a more efficient technology. As for the bill, I live by myself with no AC, using propane range and water heater and my bill was over 200$ last month though it's usually more like 130. (Oh and my grow room is only pulling about 500watts right now, 400+ in CFLs and about 80 in fans.) Again just stating that there is a basic easy way to figure out a bill and 138$ from 400watts is not happening.
I agree on service load size though, and yeah even though appliances may be more efficient then ever we are still as a whole drawing more power then ever. Hell originally a house would have a single light and a receptical which they could connect an ice box to. Today though, out of 100Amps if you had two general appliance circuits which you would, 40amps would already be dedicated to that, then 20 more amps for a laundry circuit, and what 3 watts per sq/ft of general lighting. Of course those would never pull full load all at once, but on the otherside you'd never run an electrical dryer on 20amps and your looking at 50+amps for a range. (I'm running a 200A 40 slot panel board but it's a bit overkill, 100Amp would run me but would be about maxed)

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That bill is hard to swallow I'm wondering if the meter reader might have made a mistake, I had an old aunt who lived alone in a small apartment and she would go down to the local power companies office and pay the bill in person and if her bill was over $13.00 she'd argue it with them till they lowered it she was a funny old lady she would only watch Lawrence Welk on her television on Sunday night and read the newspaper by the street light till it got dark then she used a 15 watt buld to finish the paper.
Today people leave the television running to keep the dog company while they're out it's a different world today I leave my comp on 24/7 right now I'm out on the porch doing this and the television is on waiting for me to throw a dvd in.
I know I waste alot of electric it's just a bad habit.
My lights and fan probably are going about 500 watts but I put the fan on a timer only running on for 15 mins and off for 15 mins. I don't run all the lights all the time 4 of them run for an hour every three hours the rest are on the 16/8 it's just an experiment to randomize the lighting from strong to average.
I don't know if it will have any effect positive or negative but I wanted to try it to see what would happen.
I thought running the extra four at odd on and off times would simulate the effect of clouds coming and going as in nature.
Probably just a silly experiment the remaing light supports the normal growth cycle, I'm also trying to come up with a way to rotate the plants every three hours a quarter turn to get balanced lighting on the plants.
It probably seems to be a bit odd to do all those things I'm just curious to see what will come of it.

BigBudBalls said:

All true, but at any given time everything *could* be on. (granted not heat and AC)

So if I read you right, no prob with having say a 75 amp sub panel with 200 amps worth of breakers in it?
(I use 200 figuring 75 per leg would be 150 to single pole breakers)

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The one time I installed one of those on demand hot water heaters it was on a 200 amp. service in a small two or three bedroom home with only one occupant.
An older man who was worried about paying to keep the water hot all the time.
I've only seen one customer who pulled near 100 amps on one leg of his service but he was running a business out of his home, I just moved a couple of circuits to ballance out the 200 amp. panel.
I remember hearing about an electrician with a gambling problem who would go up to a panel in front of the homeowner and count up the breakers adding all the breakers up and then he would tell the home owner he was pulling too much power for the 100 amp service and it ws dangerous just to sell them a 200 amp upgrade.
As far as the sub panel goes I would want to at least try to get a good Idea of what they usually use as far as loads go if it were an all electric home heat, stove, wall oven, hot tub, pool etc. I wouldn't want to install one without checking but 200 amps goes a long way.
Loads change sometimes by the minute appliances cycle on and off, I really wouldn't offe ran opinion without seeing things for myself I could say yes only later to find they have say a Federal panel I don't like adding anything to those I'd rather get them away from that brand.
If I had a Federal panel the first thing I'd do was change my panel before the sun set if it were my home just as an example.
I'm very leary about giving any advice on here I would feel more comfortable seeing the situation and then giving advice, but that's not possible.
It comes from doing alot of insurance jobs I've rewired too many homes that have had fires in them.
I've seen some crazy stuff.

Are you in the IBEW, bro?

DenseBuds said:

I have a relatively small two tent veg(2-2ft, 4bulb T5s)/flower(250watt HPS) setup in my home office. Using my Kill-a-watt, I've determined that I'm pulling ~ 4amps for lights and fans (soil grow, so that's it).

However, since it's a home office and I work from home frequently in addition to being a huge computer geek, I have multiple (4-5) computers running 24x7, pulling around 1.5amps a piece. Also, I live in the desert where it frequently hits 115 in the summer. Since I need to keep the door closed for both work and grow reasons, the room gets crazy hot during the summer. To combat this, I also have a portable A/C unit in the room.

I have to plug the A/C into an extension cord into the next room or I trip the breaker. Also, I had to move my wife's treadmill into the guest bedroom. I'm looking to rectify this.

I'm thinking that what I need to do is have an electrician out to run a dedicated circuit (thinking 20amp to account for possible expansion?) to plug either my grow setup or computers into and the A/C or Treadmill into. Right?

Here are pics of my breaker box. Can anyone give me a rough estimate of how much it might cost to have an extra circuit added to the box and run to my grow room/office? It's on the opposite side of the house from the box, but it's a 1-story 2300 sq foot house, so it's not terribly far.

Thanks,
DB

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Well I can't see the whole panel many companies use the same cover on several panels I see two open knock outs on the panel cover but that doesn't mean that there is anything behind them, but lets say you have room in the panel I would run 2 new circuits it's cheaper to do it now one for the comps and one for the ac it's cheaper to have him or her do it in one trip than to pay him to come back a second time. it would also free up the existing circuits your using.
if you were to hav e2 120 volt circuits ran the electrician could run a three wire cable and split the circuit sharing the neutral between the two live wires.
And then you could use the new circuits for what ever you need them for one word of advice make sure he doesn't have to have access to your grow room to run the wires through but if he does you'll probably want to move your plants while the job is getting done.

Good point on the 2 circuits vs 1. I do have open knockouts on the panel. Is that the only concern? I wad worried that the main breaker being 200 wouldn't be enough and I'd need to upgrade that somehow.

Thanks!

200 Should be plenty. Easy way to figure your amp load is just take the Watts being used, and divide that by the nominal voltage. So for say a computer you would divide X watts by 120, or 240 for things like the range. Also on appliances like the range or dryer you need to then multiply that amperage you get after you did the division by 1.25. (Old houses would be 110/220, or 115) 12/3 awg would probably handle your new room fine though like I believe Karloff is saying.

AquafinaOrbit said:

200 Should be plenty. Easy way to figure your amp load is just take the Watts being used, and divide that by the nominal voltage. So for say a computer you would divide X watts by 120, or 240 for things like the range. Also on appliances like the range or dryer you need to then multiply that amperage you get after you did the division by 1.25. (Old houses would be 110/220, or 115) 12/3 awg would probably handle your new room fine though like I believe Karloff is saying.

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Yes a 12/3 wire for the circuit or circuits would be what I meant.

teebeekahuna said:

Are you in the IBEW, bro?

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No I was never in the union although I sometimes wish I was but at the time i started in the field my friends and relatives who were spent more time on layoffs than working it was during the last recession funny how history repeats it's starting to look like the eighties all over again.
But if I was in the union I'd be retired by now.
Ahh the road not taken.
I do support the union guys.
I did mostly custom high end homes specialty wiring the last few years I did alot of insurance work fires, floods, lightning strikes etc. some of it was interesting even got to meet Springsteen.

bricktown73 said:

Hi there fellow RIU'ers... Over and over again I continualy see new threads and posts about electrical work question and thought I would post a couple threads to help you guys the same way all of you who have done such a great job having helped me... So, Do you have a grow room question about how to wire something up, or what are the safest ways of doing things? The most important one I see alot is people running lights and fans off power chords... I have wired my own grow room and will post an example of my work.

Please, if you have any questions and are unsure of what to do or if what you are doing is safe, PLEASE! ask me first if you are even a tad bit unsure. I would hate to hear anyone have an electrical fire because they didn't quite know what they were doing when all they needed to do was to ask a couple of questions... I will do my best to point you in the right direction.

If you want to do some wiring your self, I will either let you know if your project is too complicated if your not handy with electrical, or, IF YOU ASK, I will walk you thru your project step by step.

So please, ASK AWAY!!!

You can post questions here but you may not get your question answerd on the thread, best way to go about it is PM me. You will forsure get a response back.

PS Even if you have basic around the home electrical questions, shoot em my way.

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Alright man if you ever need any advice about UK wiring give us a shout, i am a electrician and its a different ball game over here.