# How to check the power capabilities of a house?

I'm planning a wedding, and the current plan is to have it at my fiancée's aunt's house, which has a large avocado orchard in the back. We love the space, but it just occurred to me: I'm not entirely sure her house can handle the power drain of the DJ, lights, decorations, rented bathrooms, etc.

I have basically zero experience with this sort of thing, but I find myself needing to check the power capabilities of this house. I have a vague notion that the information I need will be near the breaker box, but what specifically should I be looking for? And what information (wattage, voltage, etc) will I need to get from my DJ and such, to total up and compare to the house's capability?

• You might want to consider renting a generator, or asking the DJ if they have one that can be used. – Tester101 Aug 28 '15 at 13:51
• There's probably a main breaker in the electrical panel, on the handle there should be a number printed. That number is the maximum load in amperes that can be drawn. Wattage = Volts x Amperes. Don't forget, you'll still have to power everything in the house, as well as all the party stuff. The DJ, lights, etc. might not require all that much power, but getting the power from the house to the party could be a challenge in itself. Which is why a generator might be a handy thing to have. – Tester101 Aug 28 '15 at 13:56

Go to the main breaker box and find the main breaker, or "Service Disconnect". It will be separated from the other breakers, and perhaps even in a different box.

The number on the breaker, eg "100" is the max number of amps that your box is wired for (Of course, you would need to distribute your load appropriately.

Have you looked into renting a large generator for the day?

• I haven't looked into generators, but I'm beginning to suspect that I need to. So the maximum load is measured in amps? Is that something I can ask people, like my DJ, how much they need, or is that a less common unit than watts, etc? – Nerrolken Aug 28 '15 at 13:54
• I would suggest asking about wattage. That would be more common for that kind of equipment. – BrownRedHawk Aug 28 '15 at 14:18
• @Nerrolken most DJs would know what they need in both watts and amps. If not there are simple calculators online. Its just Watts=Volts*Amps – Grant Aug 28 '15 at 14:18
• If you are in the US, Amps = Watts / 120 – BlueRaja - Danny Pflughoeft Aug 28 '15 at 18:49
• Given that the main breaker capacity is being considered for at least part of this question, watts/240 also applies (unless it's more complicated by being 3-phase.) A 100 amp main (single phase, 240V) supplies 24000 watts. – Ecnerwal Aug 29 '15 at 0:11

The main breaker shows the total Amps allowable. It is usually outside by the meter or in the house inside the main panel.

### Things to Consider

Under normal conditions an average home will consume between 20 - 30 amps continuously. Without physically testing with an Amp probe, there is no definite certainty of knowing what the average Amp load is.

### Hypothetical

If you have 5 empty breaker spaces in the main panel you could pull 5 dedicated circuits. 3 for the DJ/band, and two for lights and other miscellaneous needs. Each circuit would be protected by a dedicated GFCI 20 Amp breaker.

### Materials

500+ feet of SJ cord #12/3 \$650

5 GFCI breakers \$280

Weather rated receptacles and covers \$90

Labor: installation and removal. \$1600

Grand Total \$2680

### Alternative

5 20 Amp circuits is roughly 10kW of power

As this is just a one time event, the cost of renting a 10kW generator might be the smart approach financially as well as safety is concerned. The generator should come equipped with GFCI protection too but double check before the rental is finalized.

Even with a generator, the SJ cord would still require the proper weather rated male/female terminations on each end and there is always the noise concern of the generator too.

Using #12 wire I would be hesitant of running it over 200 feet. Each 100' interval might require a larger wire size. For example, 300' might require #8, 400' might require #6. I say might because basic lighting loads are not as critical/sensitive as other loads like the DJ/Band equipment were voltage quality is a concern.

• Depending on how far from the building the equipment is, voltage drop on the cord could be a problem. If power quality is a concern, you could end up needing #6 cord instead of #12. That's the advantage of the generator, it can be closer to the party. The disadvantage would be noise. – Tester101 Aug 28 '15 at 20:36
• @Tester101 true. In my experience with this, #12 offers pretty decent voltage quality at distances up to 200' or less. I would be hesitant to use it on longer distances. – Kris Aug 28 '15 at 21:26