Help me design my electrical system

[bud dwyer]

Im finally a legal vegetable grower and I am now designing my grow room starting with the electric. My plan is to first run a smaller system explained below but leave room for upgrading. A good friend of mine is a journeyman electrician but id rather not exhaust him too much of the design portion and just have the material ready for him to install.

System Ill be running to start.

1. (1) 600w hps
2. (1) 500 cfm inline fan
3. (1) 250 cfm inline fan
4. (1) medium duty dehumidifier (basement)
5. (1) box fan

I also want a rock solid timer that is safe and foolproof to use. Im thinking a 220v for the light and 120v for the accessories would be best although Im not too familiar with electrical engineering. My main house panel is a short run ~15 FT. I would never want to do more than (2) 1kw lights in the future. I want to do this once and do it right. I would appreciate any help with this and if you can point me in the right direction for the safest, upgradable solution, i would be grateful.

 

[rives]

There are a number of questions that need to be answered. First of all, do you own the house or do you rent? This will determine how much you want to put into permanent infrastructure and how much it would be good to keep portable. For what you have enumerated so far, 30 amps of 120/240 would probably handle things, but personally, I wouldn't run less than 50-60. Are you going to need heating or air conditioning? How about room for a veg area or mom's? Is there a good bit of space left in your existing main panel, or are things getting snug? How many amps is your main service?

Just for you to start kicking things around, I would figure on a 60 amp sub-panel either installed permanently or on a range/dryer plug depending on the ownership issue. An Intermatic T-101 (120v) or T-104 (240v) timer is bulletproof, but the timing resolution is pretty crude because it is motor driven. If you want digital accuracy, a cheap timer driving a power relay/contactor is the best way to go. Some extra receptacles for things like pumps are a good idea, and maybe some timer-driven receptacles for side lighting or whatever.

 

[bud dwyer]

I own the house. Its pretty big and pretty old. Im not sure what amp service I have. Here are some pics of the panels I have if it helps.

 

[rives]

Oh boy. On the big panel, up in the upper right hand corner, the breakers have a sticker that says "Service Disconnect". That should be the main breaker, but I can't read the rating on it. The center picture looks like the meter might be above the sub-panel and to the right of the main - is that correct? A longer view of all of the equipment would help.

If your proposed room is only 15' away, it might be better to take the money that you have in mind for an upgrade and put it into a service change. It appears as though you have a patchwork of equipment going on already. If you replaced that equipment with a 200 amp, 40 circuit metered panel, you could really clean things up and have plenty of space in the new panel for everything that you would need for your new room.

The existing main panel looks like it has 4 breaker spaces at the bottom, but you would have to check and see if the busses actually extend down that low. If that were the case, I don't know why the sub-panel on the right would have been added because that is how many breakers that have been added with it.

If you are comfortable pulling the covers off of the panels, some detailed pictures of everything would be very helpful.

 

[bud dwyer]

My house used to be several units and then renovated into one. Thats probably why it is so messy electric wise. The sub panel runs the kitchen. Id rather not redo the service. Could I add in to the sub panel already in place if there is no room on the main?

Edit: Yes, the meter is above the sub and to the right of the main.

 

[rives]

It looks as though you have space for one double-pole (240v) breaker left in the sub. You need to find out how much power you have to start with, how much has been carried to the sub, etc. All of the remote meter bases that I have seen like that are for low-capacity services, like 60-100 amps. I've blown your picture up and still can't make out the rating on the main breaker (the "service disconnect"), but it appears as though there are only 2 digits on it.

If the feed was originally sized for a single small residence, and the other dwelling's power was swung over to it when they were combined, you may not have capacity left. If you can read the wire size on the wires feeding the service disconnect, it would help greatly.

 

[bud dwyer]

The service disconnect is 60 amp

 

[rives]

You need a service change desperately. Breakers, unless specially listed, are only supposed to deliver 80% of their rating on a continuous basis (loads of 3+ hours duration). That means that your main is really only capable of supplying 48 amps on a continuous basis. As I said up above, that is what I would want to run to the grow op, exclusive of the rest of the house.

 

[bud dwyer]

So under circumstances should I add an additional load to this setup?

 

[rives]

I wouldn't. I can't imagine how you've gotten by with what you have unless you are in a tropical climate, don't cook much and use a clothesline instead of a dryer. Most household loads outside of climate control are relatively transient, but loads from grow ops are usually of long duration. 60 amp services have been obsolete for decades - they predate lifestyles with microwaves, computers, heater/air conditioner/dehumidifiers, etc.

 

[bud dwyer]

Something may not be marked correctly here. I never blow fuses. This summer, at all times, had a central air unit running, dehumidifier, window ac unit on 3rd floor, laundry machines, tvs, cable, cooking going on all at once.

 

[rives]

That doesn't make any sense from what we are seeing here - that thing should have been glowing red under those kinds of loads. I can't imagine that you would have another service somewhere. Pictures with the covers removed would help, or maybe have your electrician friend take some amperage readings and check wire sizes. Perhaps the "service disconnect" breaker feeds the sub-panel, and the meter feeds directly to the busses without a main breaker - illegal as hell and a piss-poor idea, but if somebody originally bootlegged it in.... We need some pictures.

 

[bud dwyer]

Heres the pics with the covers off. This passed inspection when I bought the place, so I wouldnt think its currently dangerous or illegal. The wire feeding into the meter appears to be 1/0

Thanks again buddy.

 

[rives]

Well, it may have passed some kind of an inspection, but I can spot enough code violations at a glance to give an electrical inspector a coronary. Did you happen to check the wire size going to the top right hand "Service Disconnect" breaker? That is indeed the main for the whole thing, and it may be an optical illusion, but the wire coming off of the lower 60 amp breaker feeding the sub appears to be larger than the wire feeding the main.

 

[bud dwyer]

So would you say absolutely do not add another 220v circuit to this mess? Get the service redone or dont do anything at all?

 

[rives]

Personally, I wouldn't want myself or my family even sleeping there. I would very much recommend that you get the service redone, and have someone take a look at the remainder of the wiring. I don't even see a ground wire of adequate size in there to indicate that it was attached to a ground rod. There is no breaker space left in the main, the cover was a red herring. There is space left for (2) single pole or (1) double pole breaker left in the sub-panel, but the last thing that I would do is add any additional load. That thing is ugly.

 

[bud dwyer]

Wow. I had no idea the system was that bad. I've had more than one person look at the box and none showed serious concern. Thanks for the insight.

 

[rives]

Correction, I think that I found the ground wire. It appears to be the cable that exits out of the top right of the enclosure, loops over the top of the two meter bases and then around behind the mounting panel. It should be bare, not insulated, but that isn't a functional concern.

The panel may be relatively safe from a grounding standpoint, but it is almost certainly badly overloaded and the workmanship is terrible. I'm undoubtedly more anal about electrical gear than most, but it comes from a lifetime of working with it. The good news is that it would be very simple to upgrade it to a new service. Good luck.

 

[bud dwyer]

Could you be kind enough to shoot me a recommendation for the material needed to upgrade the service?

 

[rives]

Well, I can get you started - it's inevitable that the list will be incomplete!

1) Outdoor-rated 200 amp 40-circuit, 40-space surface mount single-phase load center with meter socket and main breaker. Lowes carries this Square D model, which would allow you to re-use your existing breakers http://www.lowes.com/pd_12116-296-SC40M200S_0__?productId=1007115&Ntt=200+amp+meter+socket+load+center&pl=1¤tURL=&facetInfo=

2) Enough 2" rigid conduit for the riser - this is the feed to the panel from where the utility connects to your wire to the above panel.

3) A 2" weatherhead for the above

4) Enough 2/0 copper or 4/0 aluminum wire w/ THHN insulation to make (3) runs through the above riser, with enough excess to terminate on the meter socket in the load center and a couple of feet to hang out of the weatherhead for the utility to hook to.

5) Enough #4 bare copper solid wire to reach from the ground buss in the load center, through 1/2" EMT, to the ground rod.

6) 1/2" EMT for above, with box connector and ground rod clamp.

7) Clamp for the #4 wire to the ground rod

8) If there isn't one already there, an 8' copper-clad ground rod.

9) Connectors of appropriate sizes to get all of the existing romex and flex tied into the new load center

10) Staples of appropriate size to get the above mess cleaned up and anchored down within 6" of the load center.

This list is probably only +/- 50 items that you will find that you need! I can't tell from the pictures where the load center is located, but all of those penetrations going into the top of the enclosure are good places for water to run in if possible. Depending on the location, I would fabricate some type of cover over the top of the wiring to protect it from mechanical/UV damage. There really shouldn't be any splicing done inside the load center, and you may need an assortment of wire & boxes for places to splice/extend the existing wiring if it is too short to get into the panel. All of the wiring appears to come from above - another way to handle the transition into the panel would be to place a section of wiring trough (gutter) up near the top of the installation and bring all of your wire into it. You could then drop out of the bottom of it with a couple of large conduit nipples with condulets and bring the conductors into the load center through the side. This would give you a handy spot to splice any wires that needed it and clean things up immeasurably.