[Danberg]

I am going to install an AC outlet in the garage for a refrigerator.  The refrigerator is about 5 years old, fairly effecient.  Not sure which existing electrical line to tap into for the outlet.  The home is 25 years old, and wired with 12 guage grounded  wire.  Curcuit breakers are 15 amps.

Any idea on the total amps (or wattage) the refrigerator requires on start up, so that I dont overload an existing curcuit, causing the breaker to kick off when the refrigerator turns on?  Any suggestions on the maximum wattage that an existing curcuit is already using, before I should consider tapping onto another curcuit line that's using less wattage? 

I do not have an open curcuit in my breaker panel, to dedicate to just this one refrigerator outlet.     

[wgscott]

Any suggestions on the maximum wattage that an existing curcuit is already using, before I should consider tapping onto another curcuit line that's using less wattage? 

The upper bound is 120 V X 15 amp = 1800 Watt.  You can guess what the initial surge current (or wattage) would be by multiplying the rated (or measured) current by 3 (very approximately).  An average (non-compressor) refrigerator will use 60 to 180 Watts.

[Mike B.]

electrical codes do change somewhat from one state to another. There is usually a max number of outlets allowed per circuit. So I would think determining the number of outlets/light fixture outlets on a given circuit would be the first thing to check. There should be a power requirement tag on the back of your refrigerator. Most homes have multi outlets on the same circuit as their refrig, so I doubt it would pull more that 5-8 amps?

[Wayner]

15 amp Ground Fault Circuit Interrupter.

Wayner

[ctviggen]

15 amp Ground Fault Circuit Interrupter.

Wayner

They just changed the code to require GFCI for this type of circuit.  However, the GFCI may or may not trip for the fridge.  I've had no troubles running a freezer off of GFCI and I also run garage door openers off GFCI with no problems.  My friend, on the other hand, had to bypass his GFCI in order to run his garage door opener.  So try the GFCI for a while to see what happens.

[Wayner]

If the GFCI doesn't work, it's (A) defective or (B) doing it's job, and there are other troubles with the unit that need to be addressed. I suspect that every GFCI goes thru some damn tough tests, so I pick (B).

Wayner

[ctviggen]

I am going to install an AC outlet in the garage for a refrigerator.  The refrigerator is about 5 years old, fairly effecient.  Not sure which existing electrical line to tap into for the outlet.  The home is 25 years old, and wired with 12 guage grounded  wire.  Curcuit breakers are 15 amps.

Any idea on the total amps (or wattage) the refrigerator requires on start up, so that I dont overload an existing curcuit, causing the breaker to kick off when the refrigerator turns on?  Any suggestions on the maximum wattage that an existing curcuit is already using, before I should consider tapping onto another curcuit line that's using less wattage? 

I do not have an open curcuit in my breaker panel, to dedicate to just this one refrigerator outlet.   

Have you mapped out the circuits to determine which one to add to?  I've mapped out all the circuits in my house, but it took a while.  Everything is entered into a spreadsheet (yes, I am a geek).  Interesting that they used 15 amp breakers with 12 gauge wire, since you could put a 20 amp breaker on 12 gauge wire (according to the NEC, anyway). 

The problem is, how do you calculate amperage/wattage for outlets?  A typical calculation is 1 amp per duplex outlet, but that varied per jurisdiction.  And some jurisdictions have a maximum number of duplex outlets of 10 or less per circuit (not code, though).  Where it gets really confusing is where you have light wattage one a circuit, along with several outlets.

Take a look at this load calculator, which has a common limit of 12 amps on a 15 amp circuit:


http://electrical.about.com/od/panelsdistribution/f/calculateload.htm

This one is even more restrictive, though it uses 20 amps (reduces max load by 60 percent), but still allows 12 outlets!

http://www.ehow.com/how_6400572_determine-number-outlets-electrical-circuit.html

So, these rules (and the rating from your fridge) will help determine what circuit to use.

[ctviggen]

If the GFCI doesn't work, it's (A) defective or (B) doing it's job, and there are other troubles with the unit that need to be addressed. I suspect that every GFCI goes thru some damn tough tests, so I pick (B).

Wayner

New GFCI are much better than old.  I've had old ones trip periodically for seemingly no reason.  Even a new one I installed recently trips when I remove the plug from the heater I use to light my charcoal.  The GFCI trips every freaking time, and it's brand new.  And the heater is the only thing running on the circuit and isn't near the wattage rating of the circuit.  If that's your fridge/freezer, you end up with ruined food. 

[django11]

Not sure about USA but in Canada when the box is full we use twin breakers.  It's just two breakers in the space of one "normal" one.

[wakibaki]

Where do you live? It's illegal to do modifications like this in the UK unless you have certification. The police won't come round, but if you're unlucky enough to have a fire your insurance will be void.

w

[Danberg]

Thanks for all the information, I appreciate the input.  By the way I live in Ohio. 

Wayner, you are probably correct about the GFI, and I would put one in EXCEPT... the fridge is plugged into one already in the garage (different area than I want to move it to) and the GFI has tripped 3 times over the last 5 years and unforunately runied food each time!    No aparent reason to trip, no other items are plugged into or running on that circuit.  This last time, I have had ENOUGH OF it!!!  As far as I am concerned, this is where 'common sense" is going to prevail over "governmental regulations!!  No GFI anymore to the fridge.

I also "mapped out" all my circuits years ago, thats why I was interested in getting an idea how much wattage or current the fridge will draw when it comes on.  I don't want to overload the circuit I tie the fridge outlet into.

Also, I agree in that 20 amp circuit breakers can be legally used with 12 guage wire, but all breakers are 15 amp in  the breaker box. 

 

[Elizabeth]

A friend of mine added circuits to his garage, and he was an electrician apprentice at the time. Well he was forced to rip it out entirely due to not getting a permit for it.
Lesson learned is do not add a circuit without finding out the local laws concerning the adding of that outlet.

""Thousands of government workers prowl the countryside watching for piddly stuff like your improvement, just looking for a way to ticket hardworking folks.    They have spies everywhere. Just waiting for a chance to harass someone.""
(8^Q...

[ctviggen]

Oops, I forgot.  My jurisdiction is under the 2005 code, so I have my fridge on a non-GFCI outlet.  The other outlets I installed off of that are GFCI. 

Hmmm...That's what they did in my house, too. They used 12 gauge wire but only have 15 amp circuits.  I've totally reconstructed the room through which all the wires run and in which the breaker box is, so I can tell the size of the wires.  However, I can't tell if the entire run is 12 gauge, so I've not changed the breakers.  Also, they did some strange circuitry where there are two 15 amp circuits that share the same ground. (Can't remember the name of this right now.) This is legal, but it's not often done today.  Certainly, I never used this.  It's just as easy to run independent circuits, though perhaps slightly more expensive.  Considering the most expensive part is drilling the holes and routing the wire, I consider the minor extra expense of separate circuits and larger wire to be minimal.  I used no 14 gauge wire, unless it's a branch circuit directly to a single light.  I also use 10 gauge wire for 20 amp circuits (garage outlets, microwave, circuit in attic, circuits for two HT systems).