Power Requirement for Chest Freezer?

[reub]

Hi All,

Thanks to everyone who's posted with great information on chest freezers in past threads. I have one question that I don't think has yet been discussed.

We're looking at putting in a small (5-8 cubic foot) chest freezer in our condo, but due to the (poor) way the electrical was installed, it might have to go on a 15 Amp circuit that's shared by a number of lights and electronics.

For those who have chest freezers, do you have them on a dedicated circuit? Do you know if they need to be? Any suggestions?

[oldunc]

Current practice is to use dedicated circuits for all large appliances that turn themselves on- this prevents such things as your freezer blowing the breaker while you're on vacation due to other loads. Electric motors will create power surges when they kick on, sometimes quite large ones. Modern circuit breakers are designed to ride out those surges, but in an apartment you may have some pretty old equipment, and landlords are notorious for skimping on installation- you can't always count on building departments to have caught improper installations. That said, my mother ran a woodshop off the same, 1954 vintage 15 amp breaker with a chest freezer that size for years without actually blowing the circuit .
A properly installed electrical system`should protect you from any actual fire danger, but it's best not to push it.

[lcool]

question,your opinion about a "single item" surge protector here

[itzelectric2]

Surge protector for your freezer? I would say sure, as long as it is rated to handle the motor and compressor of the freezer... also, some people get a whole house surge protector that is installed in your electric panel. Personally, I don't like those because they run around 100 bucks and are only good for one shot.... my personal preference is, if you have frequent surges due to lightning, your best bet is to get a lighting rod arrestor system instilled. You can get a complete kit for around 5-600 bucks, and I have seen them much less if you shop around, and they work after infinite number of lighting strikes.

[oldunc]

??????Surge protectors have nothing to do with it- the surge is the power required by the motor (or other device, such as a ballast) to get started. It poses no threat to the motor, which requires it, but can cause a breaker to throw. Modern "slow blow" fuses and breakers are designed to avoid this.

[lcool]

oldunc and itzelectric2 my question was more as maybe applied to the OP
We have two friends that live in apt/condo with some age on them that really should be updated IMO.Both have little,<8' freezers.Live with frequent power outs and flickers.Ergo wall socket surge protectors,good ones are being used for electronics by both.Both care as much about protecting the frig and freezer.So would it make sense to gift them each with one?Neither is overloading a line or careless.
I am with both of you regarding load and real protection,as is engineer spouse and electrical engineer BIL.Our permanent move here,small farm was delayed waiting for two more lines.We only wanted/needed one.Got two because of the rediculous wait to get them.We had enough plus 15% = not enough for anything extra. Our power co was recently voted #1,"WORST COMPANIES" in America. We have 21st century surge and lightning protection.Way cheaper than replacing either well pump because of .. their crappy service and maintanance.
Both live where our supplier is even worse/problematic.You can hear transformers screaming even in minor weather glitches.

[itzelectric2]

Of course, dedicated circuits are definitely preferred. Perhaps I should have clarified my post more... I simply meant to inform people who how to know whether or not an existing receptacle could support any given appliance. As long as you do not load a circuit over 80% of the breaker rating you should be fine. In some cases it may not be possible, or at least not cost effective, to run a new circuit, especially if you are a renter. The information I gave above should help one to determine what size appliance they can get, if any at all. Most definitely you should seek the help of a licensed electrician that is familiar with local codes.

[Bada Bing]

Because you are an electrician, I'll ask you one thing. I put a freezer in a garage with a standard 15 amp circuit. I can't recall the exact amperage of the freezer, but it was way under 15 amps. But I also use some power tools for woodworking in the garage. The table saw and even my circular saw are rated at 15 amps. I created a system where I can shut off power to the freezer if I'm using those tools. But according to your 80% rule, even those tools alone are too much for a 15 amp circuit. Am I right to think that the fact of my using them only a few seconds or maybe 30 seconds at a time is why I haven't had the house burn down yet?

[oldunc]

They'll only draw those amperages under full load, which seldom happens. If you're ripping a lot of 3" maple, you'll have problems,but under more usual loads you will only draw a fraction of the rated amperage. The chest freezer should be drawing no power most of the time, they're very efficient at holding a temperature once they're there.Your house won't burn down if the wiring is correct, you'll simply blow a breaker; that's why they're there.

[itzelectric2]

Oldunc is absolutely correct. The 80% rule I mentioned is to ne applied to continuous loads to prevent overheating of wires. Continuous loads as defined by code are those that run continuously for at least 3 hours or more. And as oldunc said, most equipment only runs at max load under certain conditions, i.e., a circular saw cutting through very hard wood, tourquing the motor. And lcool, to answer your question, if there are frequent power surges due to lighting storms, I stand by what I said about lighting rod systems. As I said, you can buy a kit that includes the lightning rod, cable, etc and install on the house. A sufficiently sized lighting rod system properly instilled and adequately grounded will attract the lighting and send it to ground. Electricity wants the easiest path to ground and will take it... sometimes that is through your electronic devices because they are grounded. If you have a better source of ground that bypassed your home, the lightning will take it instead. And when I say 'ground', it is not some technical electrical term, it literally means ground or earth. The lighting rod system is a bit more expensive than a whole house surge protector, but will last many times longer. If power surges are rare, I definitely recommend having an electrician installing a surge protector in your panel. If they are frequent, though, you will be spending about $100 per surge, as these types only are good for one hit.

[lcool]

Understand the "ground",spouse is in Arboriculture/Tree business.Our electrician installs lightning protection in trees and on irrigation systems for many of his clients.

we are all new with excess capacity and protection here,but your news is likely a sad note for our apt/condo friends and my small gift idea

[itzelectric2]

Don't get me wrong... if you are worried about a surge taking out something, by all means put a surge protector on it! They are designed to protect against that.... just make sure you buy one that comes with a definite warranty that will cover whatever equipment you have plugged into it, because I have heard of people who's computers that were plugged into a surge protector got wiped out.... (so always make sure that is backed up). I simply suggest the lightning rod system where possible i.e. your own house where surges are frequent. They are more costly up front and cheaper in the long run (as well as better protection when properly installed). However, surge protectors are perfectly fine...... like I said, the only reason I don't like them is because they are only good one time, but they do work...... or at least guarantee to replace up to a certain dollar amount if they fail...

[lcool]

considering both folks don't have much other option I will gift these
Really good ones for their electronis/computers paid off with the "renters insurance" policy.

[itzelectric2]

This is obviously quite an old post, but this reply is for any future questions similar to this... I am an electrician and I can tell you it is more than simply subtracting the appliance amp rating from he circuit breaker rating. Electricity creates heat, heat in turn can melt wires, that is why you have different size wires that can carry more current, because the more current you have the more heat it can create, that is why you NEVER want to simply change your breaker size. Whatever your breaker size, if you have any loads on that circuit that can be on for 3 hours or more (i.e. lights) you have to derate that circuit to 80% max current. For example, you would only want to load a 15amp circuit to 12 amps, this gives enough 'cushion' to allow for heat build up (and is code). A simple way to figure your circuit load is to find all loads on that circuit (lights, or appliances that are plugged in, etc.) And add up all the current values. If you are at 12amps or less, you are good (for a 15amp breaker... a 20amp would be 16amps). If you do not know the current value on something, you can generally find the watts, for example a 100 watt light bulb. To find the current rating, take the wattage and divide by the electricity used... for anything 120v, divide by 120, and for anything 240, divide by 240. So a 100watt light bulb would be 100 watts divided by 120volts. That is about .83 amps. Hope this helps. :)

[Alacrity59]

I'm not an electrician but heck I've taken physics. Our freezer is about 7.5 Cubic Feet. It is rated at 5 Amps. On a 15 Amp circuit that would leave 10 Amps for other stuff. A 100 watt light bulb is 0.83 AMPS so you could run about 10. You really would not want to have your freezer on the same circuit as any of the following. . . hairdryer, kettle, toaster oven or other high wattage or amperage stuff.

[reub]

Alacrity - Thanks - the 5 amp rating is good context. We ordered a 7.2 cf Frigidaire. I haven't been able to find out an amperage rating on it and even if I could, I'm not sure how I'd measure the existing load on the circuit. From what I'm told, I can't just up the breaker as the wiring has likely been done with a gauge to match the breaker. I'd rather not rewire the whole place...

Any other apartment dwellers out there with freezers? Have you faced similar issues?