You can go to Lowe's and buy a GFIC outlet box that is already attached to an extension cord.

How do you intend to protect that cord? Outdoor extensions cords and devices like that are not intended for permanent installation where they are exposed to the elements. If you would have a problem, like a fire, due to a cord deteriorating, your insurance adjuster may not be too friendly about losses. If you're that close to an outlet, you could easily run code-approved conduit over from the box and run wires through so that you would have an outlet in the greenhouse. This could either be a GFCI receptacle, or you could plug a GFCI-protected outlet box in to it.

Yep a good quality plastic coated cord may not last more than 20 years exposed to the weather all the time.
If you don't use the GH year round then you could wind the cord up and put it away until needed and get more service from it.

Great....I am so excited about the 20 years part. I have 14 more years to go, oh well, I will have a different greenhouse by then, but I am glad to know, I still have life on my cord. I just have to remember not to run over it with the lawn mower. Ouch!

Wiring an extra outlet is easy. Do it the right way like kudzu9 says.

Kudzu,
I'm an insurance adjuster, so you think that would occur to me , but no...
If only this wiring business didn't confuse me so.
code-approved conduit? what's a conduit?
running wires? how do I do that?
what's a receptacle?

::hides::

Many people put in conduit but don't use the special underground wire and when it fills with water it fails anyway. If you are going to bury it be sure you use the underground cable. Where I have my greenhouse it must be considered as being portable building codes are a PITA
Sometimes when we give advice it is based on what are own situation is and it may not be the best option for someone else. Example I have 80 amp service in my GH that means buying either a 100 amp service cable BIG-$$$$$$$$ or running four 20 amp lines.
My advice is do what is best for your needs which ever way you think that would be. DO USE a GFI

100A! that's a lot of power. I would be looking at a higher voltage instead.

[quote]code-approved conduit? what's a conduit?
what's a receptacle?[/quote]

This picture should help.

http://www.rd.com/images/tfhimport/2004/20040501_Electrical_Conduit_page002img001_size2.jpg

Wiring has evolved a lot from days of old as people have learned what works in what situations. If you can believe it, for years, home wiring was *bare wiring* on the *surface of walls*, just *stapled in place*. Hiding it behind walls just made the fires easier to hide, even when they used cloth (yes, cloth) to try and insulate it from the wood. The first great advance was ceramic conduits for bare wires, but of course, the wires still corroded and sparked, and the conduits could be damaged. Even the first "insulated" wires were just wrapped in cloth (or even paper), sometimes with a bit of tar.

Things have come a long way. :)

Back to the original topic. Basically, an electrical conduit is a bit of pipe that protects your wires -- from cutting damage, from water, etc. As for "receptacle", think "outlet". Conventional receptacles have two places to plug in devices. Modern ones have grounding slots. Make sure you use them -- they're there for a reason! They connect to a green grounding terminal on the back, and that should be hooked up to ground. Since your receptacle will be in a greenhouse, it should be an "outdoor" one (the type with the protective cover), not an indoor one.

If you're curious what the code is, NFPA-70 is the standard (if you want a guide, look on Ebay -- ones a few years old lose a lot of their original price). Cities generally adopt it, occasionally with some modifications, as their own local wiring codes. It's a liability thing; while you're not guaranteed a problem if you don't follow the guidelines, if you don't, and something goes wrong, you can be sued for negligence. You can still be sued if you followed the code, but it'd be a lot harder to prove negligence.

Of course, I'm one to talk about this. I never have more than a dozen watts of DC hooked up to my greenhouse, so I just buried some spare insulated copper wire that I had laying around the house and hooked it straight up to the fans without even checking what it was rated for ;) The fans are grounded to the metal frame of the greenhouse. With such low amounts of power, I'm not concerned. Worst case, a wire gets damaged? I track it down with my multimeter and replace it; they're only a couple inches underground.

I have over 1500 watts of fluorescent lights.I'm not aware of any fluorescent grow lights that are 220 so I would need to run both 220 and 110 that would be costly.
Like I said in earlier post we all have different needs. My GH will sit empty 10 months a year it will be used to start plants from seed in the spring. I have to keep everything looking like it is portable due to code so I have what is the best setup for my particular situation.

All my fluoros are 240V. I'm sure you could buy them there too. Or you could hook two in series. Or use an autotransformer.

karen, what do you use your dozen watts for?

Fans. Little ones. My current GH is small, and I have pretty good circulation even without them, so I don't need some big power guzzlers.

I'm surprised that a small, low power fan does much at all.

nathanhurst,

Check out the wind power sites...

A 10mph "wind" moves a lot of air around but it does not generate much electricity.

I assume the reverse is true.

A small fan won't move much air. Look at wind power sites - small bladed wind turbines do not generate much power.

>Posted by heebiejeebie (My Page) on
Tue, Dec 12, 06 at 17:30

>If only this wiring business didn't confuse me so.
code-approved conduit? what's a conduit?
running wires? how do I do that?
what's a receptacle? ::hides::

hj if this is not a joke, then you really should consult with a friend who knows electrickery lest you kill yourself tending to your GH!

You can easily try a GFCI in your shed, and plug-in a "super-strength" extension cord to it as you say, but this likely will result in the GFCI being tripped most of the time, and perhaps at the time when you most need it (an electric heater for instance, protecting plants from freezing). The GH is a humid environment and the GFCI will trip-on-a-droplet.

Consult an electrician please, who will talk to you about what you're intending to power...

Nathan: Yeah -- four computer case fans, 30-40 CFM each. That's not much, but I have a little GH, so I don't need much. It doesn't meet the "circulate all air once every minute and a half" recommendation, but the temps stay within what I consider reasonable, so I don't feel I need more. In the summer, I leave the door wide open, and on a small GH, that keeps the temperatures nice (even without any fans).

When your fans are free (they were sitting around in my computer closet), you take what you can get ;)

karen, yeah, I understand! Those computer fans are certainly tempting, but I do worry that they are going to be very inefficient for larger projects. A nice thing about using them for your v-tube project is that you can have a separate fan on each tube avoiding a plenum.

This is not a joke. I have an IDEA of what these things are, but I'm scared of electricity.

I'd like to make this safe, but at the same time, I'm only going to be using this set up for two years before we move. Furthermore we'd only be using it for 2-3 months a year for seedstarting.

I want to use electricity for two small electric fans.

My GH is two RIGHT next to my shed. I could drill a hole in both... very short extension cord.

ORCHID DUDE!!!!!! WHAT DO YOU DO?????????

no drama please guys thanks

Lowes has a plug-in gfci for around $10. Maybe, you could plug that in the shed, run a short, heavy duty extension cord to the gh, and plug in one of those weatherproof multi outlet units used for landscape lighting, you know, the ones with the anti splash cover? As long as no one is going to trip over, chew, or mow the cord, I don't see why it wouldn't do what you need it to for two years.

Alia

Heebeejeebee,

You're worrying too much about this. Just buy a heavy duty outdoor type extention cord with a built in GFCI. Go to Walmart and buy a 1500 watt electric heater. The small milkhouse heater they sell cost under $15.00 and works very well. If it dies (which is the most likely thing after a few months just get another one, they're cheap). Since you aren't plugging it into your house there is no danger that you are going to burn the house down. The GFCI will shut the heater off if it overheats the cord so you won't burn the shed down either.
You aren't going to be running this thing very long and you won't be needing extensive equipment like the bigger houses. All you want is to keep your seedlings from freezing, right? I wouldn't try to run a fan and a heater at the same time off the same cord . Much better to pass on the fan for now.Those small heaters have a built in fan so there will be a little air movement going on in that small space.

MollyD

I meant two small heaters, not two small fans.

Molly,
I think I want to hug you.

WARNING!!!!!!

Those electric heaters are designed to be used in a home, not a greenhouse.

To use one in a greenhouse you have to know the risk you are taking.

A greenhouse is, and should be, regarded as "outdoors"

You should only use equipment that is either specifically for a greenhouse, or equipment designed for indoor/outdoor use. (think Christmas lights... some are indoor only, for a reason)

You got all that? :) (I got the legal disclaimer out of the way)

I would use this heater, two power settings, Use the low one when the weather is mild so the heater turns on and off only a few times an hour. Switch it to high if you expect a low 20F. (there is another thread on here about "short cycling" of heaters.)

Glad you got things sorted out, next big problem is plug trays, dirt and seeds!

Here is a link that might be useful: Ideal electric heater for a 6x8 HFGH

Dear Chris,
I want to blow up my backyard.
Love,
Heebiejeebie

Dear Chris,
Why do you find this heater to be ideal for HFGH?
Is it rated for outdoor use?
What if I want to heat my GF to 60 degrees in 20 degree weather? Wouldn't I need TWO OF THEM based on those handy BTU calculators?

I'm not trying to incite a riot, of course not

""Dear Chris,
I want to blow up my backyard.
Love,
Heebiejeebie""

OK you should have kept that infra-red propane heater, connected it to a 20lbs tank, put the tank infront of the heater, opened the roof vent then beat feet outa town!

"Dear Chris,
Why do you find this heater to be ideal for HFGH?""

Because it has a fan and it blows 360 deg, Put it in the middle and you won't have any cold spots in there. Also because it is throwing heat out in all directions you won't have any hot spots to worry about.

""Is it rated for outdoor use?""

Hell no! It is an indoor heater so respect that fact, just like a tiger is not a pet. Treated right you can use it in a greenhouse, just like you can cuddle a full grown tiger. Forget what you are dealing with and you get this..

http://www.cnn.com/2003/SHOWBIZ/10/04/roy.attacked/

""What if I want to heat my GF to 60 degrees in 20 degree weather? Wouldn't I need TWO OF THEM based on those handy BTU calculators?""

If you really needed 60F and below that stuff would die then you have no choice, you need two. In the real world plants, even orchids can survive at well below 60F for a night or two.

The handy BTU calculator says that with 1500W in there at 20F you won't lose any plants.

Incite a riot?.... you are just a rookie! All you incite is a good bar room brawl.

You want to see a riot?

Just mention.... (you work it out... and no, it has nothing to do with unvented heaters)

Here is a link that might be useful: When your heater tries to kill you, um tiger. Just as deadly.

Heebie, I can't remember what BTU numbers you got from the calculator. Can you post this?

And did you figure out the amperage rating for the circuit to the shed?

SB

>Posted by mollyd 4b (My Page) on Thu, Dec 14, 06 at 21:30

>You're worrying too much about this...The GFCI will shut the heater off if it overheats the cord so you won't burn the shed down either

HJ I disagree w/Molly, sorry. You said you wanted "the benefits of a GFCI" but do you know what they are? My wife tried connecting an immersion heater (along with a fountain pump) to our outdoor fountain the other day, WHICH IS CONNECTED TO A GFCI OUTLET, and started a small grass fire! Arcing/sparking in the multi-plug adapter she was using did NOT trip the GFCI. Eventually the circuit breaker did trip, but not before making quite a mess.

A GFCI protects you from a Ground Fault, which in practical terms means if electricity leaks-out to where you can touch it (and get electrocuted) ie. to the heater's metal frame for example, well it disconnects power. But it does not, as Molly said, disconnect power if the cord overheats--your ckt breaker or fuse to the shed may do this, but then again it may not!

If you put an electric heater in your GH:
1. By all means use a GFCI cord, it should protect you if (WHEN!) the heater gets wet
2. Get a heater that turns-off if it tips over, or mount it so it WON'T tip-over (and maybe start a fire)
3. Don't come cryin' back here if your shed burns-down, and especially if the shed fire spreads to your house, or the neighbor's, from a moisture-related short-circuit that fails to trip the circuit breaker

Nothing in our GH is particularly flammable, but a fire in our shed would be a disaster (gasoline & combustibles, you know?). If it were my shed I would proably buy an arc-fault circuit breaker to serve it, but hj YOU can't install one of these.

Sorry to be dramatic, but you sound nice enough that we want you neither dead nor burned-out of house & home!

Laserfan,

"A GFCI protects you from a Ground Fault, which in practical terms means if electricity leaks-out to where you can touch it (and get electrocuted) ie. to the heater's metal frame for example, well it disconnects power. But it does not, as Molly said, disconnect power if the cord overheats--your ckt breaker or fuse to the shed may do this, but then again it may not!"

Mine did when my cord got too hot. Maybe yours was defective? GFCI are suppose to turn the power off both when something gets wet and when it's too hot for the circuit. They do become defective at times so they aren't perfect.
Nothing in life is perfect.

MollyD

Heebeegeebee and Laserfan,

Here is a nice link explaining everything a GFCI can do to protect you:

http://www.doityourself.com/stry/gfci

MollyD

Here's what OSHA says about it:

The GFCI will not protect you from line contact hazards (i.e. a person holding two "hot" wires, a hot and a neutral wire in each hand, or contacting an overhead power line). However, it protects against the most common form of electrical shock hazard, the ground-fault. It also protects against fires, overheating, and destruction of wire insulation.

from:
http://www.osha.gov/SLTC/etools/construction/electrical_incidents/gfci.html

So you see saying that the GFCI will only work when the appliance or cord is affected by water is not correct.

MollyD

I have used these heaters that HJ is talking about. My experience is that when they fail, they just quit. They get clogged with dust or debris or rust or whatever, and one day they just fail to turn on.

Disclaimer: mine are powered by a 20 amp circuit in 100amp GH subpanel, each with GFCI protection, so my experience may not be representative! :-)

I think that many heaters will eventually burn out. They probably only differ in how long it takes them to reach that point. I'm not sure if price is a factor or not. I've often found that just because you've paid more for something it doesn't necessarily last longer.

MollyD

update...
my father came over to build me these WONDERFUL shelves (birthday/yule present). While he was here we talked about electricity, he said it wouldn't be too difficult for him to run an outlet to the g-house, and we'll have a GFCI outlet!

woohoo!

I hope the weather is nice next weekend as it was this weekend. I was outside doing stuff I normally wouldn't be able to do out there until March/April.

Excellent! That'll make everything much easier for you.

MollyD

"I hope the weather is nice next weekend as it was this weekend. I was outside doing stuff I normally wouldn't be able to do out there until March/April."

There was an article in the paper on friday about how this is the warmest year on record globally. It's certainly been warmer here, and very, very, very dry (no rain for 6months, normally the wettest time of year :(

While I am enjoying the great weather alot, being in Buffalo, NY, next to Lake Erie, means that if/when the temp lowers below freezing, we will get SLAMMED with a ton of snow because the lake wont be frozen.
Frozen lake = no lake effect snow.

And that snow will hit me here where I live too so I'm hoping both Lake Eire and Lake Ontario freeze or I'm in for a ton of snow!

MollyD