Dedicated circuit for a refrigerator

[baquail2022]

Today's code calls for arc-fault breakers (outlets) in the kitchen as well. Although they are a necessity, arc fault breakers tend to degrade with constant, high usage such as found in a residential kitchen.

Most of today's modern refrigerators have a defrost heater which can pull similar amperage as a coffee maker (or more depending on size of the refrigerator) Defrost cycles usually last at least 30 minutes average. To put a refrigerator on one of the countertop circuits does not make any sense since small kitchen appliances (coffee maker, toaster, blender, crock pots, etc tend to draw 12 or more amps. If the defrost cycle starts when the coffee maker heater is still on, it can over time cause nuisance arc fault trips. The 2020 NEC code 210.52 B Exception 2, in my interpretation, is stating that a dedicated circuit SHALL be installed for each "specific appliance" which includes these larger refrigerators. Regardless most all manufacturers of these self defrosting refrigerators require a dedicated circuit to maintain warranty integrity. Am I correct that these refrigerators deserve a dedicated circuit?

In the kitchen, pantry, breakfast room, dining room, or similar area of a dwelling unit, the two or more 20-ampere small-appliance branch circuits required by 210.11(C)(1) shall serve all wall and floor receptacle outlets covered by 210.52(A), all countertop outlets covered by 210.52(C), and receptacle outlets for refrigeration equipment.
Exception No. 2: In addition to the required receptacles specified by 210.52, a receptacle outlet to serve a specific appliance shall be permitted to be supplied from an individual branch circuit rated 15 amperes or greater.

 

[suemarkp]

I don't see that as being a requirement at all. The language is permissive. You can add individual branch circuits to serve specific appliances if you wish and those do not have to be on the required two small appliance branch circuits which normally cover all kitchen and dining room receptacle outlets.

 

[don_resqcapt19]

... The 2020 NEC code 210.52 B Exception 2, in my interpretation, is stating that a dedicated circuit SHALL be installed for each "specific appliance" which includes these larger refrigerators. Regardless most all manufacturers of these self defrosting refrigerators require a dedicated circuit to maintain warranty integrity. ....

Your interpretation is 100% wrong. The exception permits an alternate installation method to the general rule that requires the refrigerator receptacle to be on one of the small appliance branch circuits. There are various reasons to put the refrigerator on its own circuit, including the manufacturer's instructions, but the language in 210.52 does not require that.

 

[LarryFine]

Welcome to the forum.

We're big on separating design choices from code requirements.

Yes, a dedicated circuit is generally preferable, unless you cant afford it.

 

[macmikeman]

It's not new code. Well, the afci part is, but the rules regarding fridges to be on small appliance circuits has been there along with the exception for a dedicated minimum 15 amp circuit for my whole career in this trade which started in 1976.

 

[tom baker]

Today's code calls for arc-fault breakers (outlets) in the kitchen as well. Although they are a necessity, arc fault breakers tend to degrade with constant, high usage such as found in a residential kitchen.

Most of today's modern refrigerators have a defrost heater which can pull similar amperage as a coffee maker (or more depending on size of the refrigerator) Defrost cycles usually last at least 30 minutes average. To put a refrigerator on one of the countertop circuits does not make any sense since small kitchen appliances (coffee maker, toaster, blender, crock pots, etc tend to draw 12 or more amps. If the defrost cycle starts when the coffee maker heater is still on, it can over time cause nuisance arc fault trips. The 2020 NEC code 210.52 B Exception 2, in my interpretation, is stating that a dedicated circuit SHALL be installed for each "specific appliance" which includes these larger refrigerators. Regardless most all manufacturers of these self defrosting refrigerators require a dedicated circuit to maintain warranty integrity. Am I correct that these refrigerators deserve a dedicated circuit?

Why does arc fault breaker when used with constant high useage loads degrade, compared to a non arc fault breaker used with constant high usesge loads?
Is it the circuit breaker components or the arc fault components?

Please explain how a coffee pot drawing 12 amps and the defrost cycle running at the same time will cause nuisance arc fault trips?

 

[baquail2022]

My statement about arc fault breakers is anecdotal in nature. I have not read any studies on this but have had several situations of this nuisance tripping during my time as an electrician. I have heard the same from other electricians whom I have personally known. Their, and my theory, is that the sensor circuit in these breakers become more sensitive over time and begin to trip without cause. In those situations where there was not an identifiable source for the the breaker to trip, the arc-fault breaker was replaced and the tripping stopped.

On rereading the code I do see that the Exception is permissive in nature and not a requirement. Thank you!

I trained under an exceptional master electrician who consistently went above the calling of the code. He believed that the code was always minimal in nature. Later on, my general contractor partner also insisted on dedicating a circuit to the refrigerator on ALL of our remodels.. I guess I was trying too hard to find justification for this practice. Thank you all for your clarity on this. -Q

 

[ESolar]

Doesn't a dedictaed circuit for a fridge have to be AFCI, CAFCI and/or GFCI (I thought CAFCI for sure)?

Lets say that I decide to wire a dedicated 15A or 20A for a fridge. If so, then that might not be a good idea because now you've increased the probablility of tripping due to those protocals. So you pulled the fridge off of an SA (without CAFCI) and potentially increased the probability of tripping with CAFCI.

Anecdotally (sample of one - variance undefined) - I've personally had my 36" fridge on a circuit with a 1000 W microwave, kitchenaid mixer, coffee pot, and spice grinder for 5 years and never tripped the SABC 20A breaker. When I also moved the toaster oven over to that SABC it did trip - so it went back to the other SABC. Most kitchens have a dedicated micro circuit. I had one, but the built in micro broke. We were using a countertop model on the SABC (as stated above). Now I've pulled the micro onto its own 20A circuit (receptacle behind a shelf). Now that SABC has a much smaller load than that which never threw a breaker in 5 years.

Neverthelss, the fridge specs have some language about a dedicated circuit that doesn't appear to be needed unless you're really hammering that SABC (like I did when I moved the toaster oven, micro, coffee pot, mixer etc. oven to it) - which you should not be doing in any case.

Thoughts?

 

[augie47]

You hit the nail on the head when you noted the Code is a minimum requirement... the prime purpose is to provide a SAFE installation.
Dedicated circuits for refrigerators and more than two small appliance circuits are desirable but not required.

 

[ESolar]

You hit the nail on the head when you noted the Code is a minimum requirement... the prime purpose is to provide a SAFE installation.
Dedicated circuits for refrigerators and more than two small appliance circuits are desirable but not required.

Am I wrong here? The problem that I see is that a dedicated circuit can be called for in the fridge specs. Then that circuit cannot be an SABC (by definition) and therefore requires CAFCI. AND that fridge cannot be on an SABC. So there you have it: code compliant rotting food and melted ice cream.

 

[ESolar]

Here is another question: If one decides to add a dedicated circuit for a fridge, then how does that figure into a load calcaultion?

Case 1: You removed the fridge from the SABC wired to the main panel and installed a new 15 amp circuit to the fridge from the main. So why would it contribut to the load?

Case 2: You removed the fridge from the SABC wired to the main panel and installed a new 15 amp circuit to the fridge from a subpanel. What is the associated load for that subpanel? Is the fridge considered as part of a lighting/receptacle load for the kitchen? Or does one have to use a name plate rating?

Also - just my opinion (not that I would ever do it): The fridge should go on the lighting circuit in a modern kitchen in which lights typically draw so little power. That way, when the lights don't work you know that the fridge/light circuit is out - no question.

 

[don_resqcapt19]

Am I wrong here? The problem that I see is that a dedicated circuit can be called for in the fridge specs. Then that circuit cannot be an SABC (by definition) and therefore requires CAFCI. AND that fridge cannot be on an SABC. So there you have it: code compliant rotting food and melted ice cream.

It doesn't matter if the refrigerator is on its own circuit or on one of the small appliance branch circuits....both circuits require AFCI protection. Kitchens were added to the list that requires the branch circuit to have AFCI protection in the 2014 code.

 

[retirede]

Here is another question: If one decides to add a dedicated circuit for a fridge, then how does that figure into a load calcaultion?

It doesn’t.

 

[LarryFine]

Nor does a sub-panel. It's use doesn't contribute to the loading. Its loads are calculated and added in as usual.

 

[ESolar]

Nor does a sub-panel. It's use doesn't contribute to the loading. Its loads are calculated and added in as usual.

Except that one cannot overload the subpanel. So a separate load calculation should be done for that. Here is a specific example that I had in mind. Let me know what you think.

I have suggested that the AL SER 50 Amp 4 wire cable on a 50 amp breaker for the range be converted to a 50 Amp subpanel feed for the kitchen to satify the AHJ on several points: (1) separate breakers called in specs for the cooktop, oven and exhaust vent, (2) lights were originally wired to the SABCs and need their own 15A circuit. In addition (not required by AHJ), the fridge is on an SABC and that could be on a separate 15A or 20A circuit. There is also a desire to remodel an adjacent bathroom that only has a 15A - it needs a 20A. Assuming that I put all of those on the subpanel, my calculations are as follows:

cooktop + oven (20A + 30A) : 38.8A (applied NEC 220.55)
vent hood (15A) : nameplate 2A x 120V/240V = 1A
Lighting + receptacle (15A) : (kitchen 200 sqft) x 3VA/240V = 2.5A
Lighting + receptacle (20A) : (bath 93 sqft) x 3VA/240V = 1.2A
Refrigerator (20A) : 0A

TOTAL : 43.5A < 50A

That fridge at 0A is code compliant? Is there some sort of 125% rule that I need to consider here and limits the load to 40A?

 

[ESolar]

What I was thinking was that the fridge is a motor/compressor. So it needs a nameplate rating + 25% (largest motor).

 

[ESolar]

You hit the nail on the head when you noted the Code is a minimum requirement... the prime purpose is to provide a SAFE installation.
Dedicated circuits for refrigerators and more than two small appliance circuits are desirable but not required.

Hi - I was not getting a response to my two questions above. I thought that I would ping you for your thoughts. See the two previous posts above by me regarding the subpanel loads with a dedicated refrigerator circuit.

 

[suemarkp]

The refrigerator is tricky. The calculation code says you can count an individual circuit for a refrigerator as zero because its load is covered in the small appliance branch circuit value of 1500VA. But you don't have any of those SABCs on your subpanel feeder, so its load is not covered there. The nameplate on the refrigerator appliance will cover the compressor at 125%, plus controls, icemaker, and lighting (I'd argue its an appliance, not a motor or HVAC load). So if you have the refrigerator nameplate, I'd add it to the subpanel calc. If not, take a trip to home depot and take a sample of nameplates there to see the range.

Worst case, install a duplex receptacle for the fridge and call it another small appliance circuit at 1500VA as that just barely fits in your calc.

 

[ESolar]

Thank you!!

 

[ESolar]

The refrigerator is tricky. The calculation code says you can count an individual circuit for a refrigerator as zero because its load is covered in the small appliance branch circuit value of 1500VA. But you don't have any of those SABCs on your subpanel feeder, so its load is not covered there. The nameplate on the refrigerator appliance will cover the compressor at 125%, plus controls, icemaker, and lighting (I'd argue its an appliance, not a motor or HVAC load). So if you have the refrigerator nameplate, I'd add it to the subpanel calc. If not, take a trip to home depot and take a sample of nameplates there to see the range.

Worst case, install a duplex receptacle for the fridge and call it another small appliance circuit at 1500VA as that just barely fits in your calc.

Actually - I think that I disagree. Here is my reasoning. If I install an additional SABC, it does not get added to the demand because:
"In each dwelling unit, the load shall be calculated at 1500 volt-amperes for each 2-wire small-appliance branch circuit as covered by 210.11(C)(1)." 210.11(C)(1) only covers 3 SABCs - 2 kitchen and one laundry. Extras would appear to be excluded from load calcultions. It makes sense because youve covered the anticipated demand and extras would be installed for convenience.