How Many Watts?

[Neal]

Alright, I need some help from the electricians.

How many watts can one outlet handle before my house blows up?

Google didn't help, and I'm sure it's not an easy answer so please expand as much as you can.

Here's some context - I have some young tortoises that I thought would be small enough to keep inside this winter, but they decided to grow a lot in the past couple of weeks, and between our family of 4 and the tortoises we already have inside, we just don't have room inside of the house for any large tortoise pens. I only have one outlet in my backyard. So on top of the adult babcocki leopard and Indian Star houses I already have out there, I'll need to add another house for the SA leopards without blowing a fuse or whatever might happen.

Thank you in advance for any input.

 

[lynnedit]

I am no electrician (one wonders why I am even commenting), but my understanding is that most plugs are 15A, IF they are the only plug on that line from the electric panel.
(some kitchen outlets are 20A).
I think the info below is simplistic in that extension cords, etc., can change the formula.

However,
amps=watts/volts.
Most of our outlets are 110V. So a 100W bulb would draw about 1 amp.
100w/110v = about 1 amp, (slightly less).

Anyway, this is how I figure out what I can put in my tort area in the greenhouse. So far, nothing has blown!

*runs and hides*

 

[wellington]

I am not electrician either. However I called my nephew he was. The important thing to know is amps. The standard house hold outlet is 15 amps. To give you a reference, I have two MVB, three Che and one flourescent UVB connected to two timer power strips and they are all pluged into one outlet. Now the next thing, is how many other outlets run off the same line. Hope this helps some.

 

[dmmj]

I am not an electrician but I do play one on TV, amps as far as I know is more important.

 

[Neal]

OK.

So based on the above, I should be ok to run...say 6 100w CHE's and 6 100w MVB's from one outlet. Anything else I have not considered in that calculation?

 

[mctlong]

I usually wait until a fuse is blown before I know how much is too much. Your method of researching prior to getting out the flashlights and candles is probably a better method....

 

[wellington]

I usually wait until a fuse is blown before I know how much is too much. Your method of researching prior to getting out the flashlights and candles is probably a better method....



Ha ha ha. Me too. Just plug in, close eyes and wait for the pop of the breaker and the darkness of the blown electric. Never thought until now to ask my nephew, duh

 

[Yvonne G]

He doesn't visit here anymore, but Balboa is an electrician. If you look for his username, then go to his CP page, you can send him an email. Or, if you belong to the "other" forum, I believe he posts there, and you can send him a PM.

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Oops...never mind. I just checked out his page and he doesn't have the email setting activated. He hasn't been here in almost a year, so sending him a PM from here would do no good.

 

[Neal]

He doesn't visit here anymore, but Balboa is an electrician. If you look for his username, then go to his CP page, you can send him an email. Or, if you belong to the "other" forum, I believe he posts there, and you can send him a PM.

---

Oops...never mind. I just checked out his page and he doesn't have the email setting activated. He hasn't been here in almost a year, so sending him a PM from here would do no good.

---

I actually keep in contact with Balboa...well as much as a friend from an internet forum would. He's not on the other forum either, but I have his number somewhere I just didn't think to call him, but you're right, he would be a good one to call.

 

[tortadise]

Your plugs are rated for 15 amps however they are on a circuit in your breaker panel that will more than likely be 15 amps. You can have 12 plugs per circuit or each breaker in the panel for plugs. Alot of times multiple bedrooms will be on one circuit. So as long as all the other plugs arent drawing over 15 amps combined on startup it shouldnt blow, however you dont want to over do or strain the circuit the wire can over heat if too much is drswn. Check that circuit by double checking the panel, if its a 20 amp definitely good. You should be ok though with what you described.

 

[jaizei]

I am no electrician (one wonders why I am even commenting), but my understanding is that most plugs are 15A, IF they are the only plug on that line from the electric panel.
(some kitchen outlets are 20A).
I think the info below is simplistic in that extension cords, etc., can change the formula.

However,
amps=watts/volts.
Most of our outlets are 110V. So a 100W bulb would draw about 1 amp.
100w/110v = about 1 amp, (slightly less).

Anyway, this is how I figure out what I can put in my tort area in the greenhouse. So far, nothing has blown!

*runs and hides*

Even though many people call it "110", 120 is actually the nominal line voltage in the US (+/- 5%). So you should use 120 for your formulas and load calculations unless you have tested the actual voltage coming in. Dedicated plugs (IF they are the only plug on that line from the electric panel) have to be equal to their circuit rating, but they can be either 15 or 20. Kitchen outlets have to be on a 20 circuit (breaker), but the receptacles themselves can be 15 amp, as long as it isn't dedicated.

---

OK.

So based on the above, I should be ok to run...say 6 100w CHE's and 6 100w MVB's from one outlet. Anything else I have not considered in that calculation?

Yes. Keep in mind that you can only load a circuit up to 80% for constant loads (more than 3 hours). So a 15 amp circuit is good for 12 amps, and 16 amps for a 20 amp circuit.

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Also, an easy way to tell if you have a 15 or 20 amp receptacle is to look at the face. A 15 amp receptacle has the 2 vertical slots on top. On a 20, the left slot is a sideways "T".

 

[Tom]

I texted an electrician friend. He says you can run up to 1800 watts on a 15 amp circuit.

But you're not allowed to sue anyone if it all goes up in flames.

 

[Neal]

I texted an electrician friend. He says you can run up to 1800 watts on a 15 amp circuit.

I talked to an electrician friend of mine after you told me this, and he said the exact same thing.

It looks like I have a 15 amp circuit, and the circuit only includes the bathroom and the backyard, so I may have some luck here. The CHE's are only on at night, and the MVB's are only on during the day so I should have a lot of flexibility if I stagger the on and off times so all the fixtures are not on at one time.

Here's the plan:

Babcocki House - 2 100w MVB's and 2 100w CHE's
Star House - 2 100w MVB's and 2 100w CHE's
Pardalis House - 1 100w MVB and 1 100w CHE

So if I stagger the on and off times of both types of bulbs, I should only be drawing 5 amps at any one time. But if I need to overlap, I would only be drawing 10 which still gives me some cushion.

Anything I overlooked? The bathroom is only going to have a 25w CFL and an electric toothbrush, so it's hardly anything.

Next year I'll have to focus on making just one big house that they can all fit into.

 

[lynnedit]

Glad it worked out!

 

[Masin]

I usually wait until a fuse is blown before I know how much is too much. Your method of researching prior to getting out the flashlights and candles is probably a better method....

We must be closely related. Although I've just moved into a historic home so it seems I'll have to try another method.

 

[DesertGrandma]

Good information. I have been wondering the same thing.