View Full Version : Can I safely plug 11.2 amp refrig and 5 amp freezer in same outlet on 20 amp circuit?
chuck1999
Sep 6, 2010, 03:15 PM
stanfortyman
Sep 6, 2010, 04:03 PM
Certainly. :)
donf
Sep 7, 2010, 06:20 PM
Question:
If either or both the refrigerator or the freezer are "Continuous" use appliances, then the answer is not a simple yes.
Since we know that these appliances are to be used on a multi outlet circuit, we know that we can only load the circuit by 80% (20*.8=16 Amps).
Also, if the refrigerator and/or the freezer are continuous use appliances, then we know that each appliance must be multiplied by 125%.
So, 11.2A * 1.25 = 14 Amps. 5A*1.25 = 6.25 A (6 amps)
14A+6A = 20 Amps on a 16Amp circuit?
ballengerb1
Sep 7, 2010, 06:47 PM
Did you mean to end with "on a 16Amp circuit'
stanfortyman
Sep 7, 2010, 06:58 PM
Question:
If either or both the refrigerator or the freezer are "Continuous" use appliances, then the answer is not a simple yes.
Don, neither of these would ever be considered a "continuous load", especially in a residence.
Since we know that these appliances are to be used on a multi outlet circuit, we know that we can only load the circuit by 80% (20*.8=16 Amps).Not quite. EACH appliance must not be more than 80% of the circuit. I think you are misreading 210.23(A)(1).
Stratmando
Sep 8, 2010, 05:48 AM
I love my food, I would have on separate Breakers, If 1 shorted out or failed, I would not lose all my food.
donf
Sep 8, 2010, 08:27 AM
Stan,
In the 2008 NEC, "Continuous Load" is defined as, "A load where the maximum current is expected to continue for 3 or more hours."
Question: A refrigerator or freezer are one 24 hours a day 365 days a year. Why would they not meet the standard given in the definition?
Is it because the full load current is cyclical and does not remain on for a duration of 3 hours?
I thought that the instructor we had was a little to liberal about the continuous use rule.
donf
Sep 8, 2010, 10:07 AM
Stan,
No, I was not basing my statement on 210.23(A)(1).
I was basing it on 210.21(B)(2) and T. 210.21(B)(2). [edited for accuracy]
(2) Total Cord-and Plug-Connected-Load.
"Where connected to a branch circuit supplying two or more receptacles or outlets, a receptacle shall not supply a total cord-and-plug-connected load in excess of the maximum specified in Table 210.21(B)(2)."
stanfortyman
Sep 8, 2010, 01:04 PM
Stan,
In the 2008 NEC, "Continuous Load" is defined as, "A load where the maximum current is expected to continue for 3 or more hours."
Question: A refrigerator or freezer are one 24 hours a day 365 days a year. Why would they not meet the standard given in the definition?
Is it because the full load current is cyclical and does not remain on for a duration of 3 hours?
Absolutely. The only time a refer or freezer would run continuously is if the door were left open, and that is not expected to happen. ;)
These appliances run for several minutes at a time and then shut down. Even a dead warm refer or freezer would not likely run for three hours to get down to temp.
stanfortyman
Sep 8, 2010, 01:09 PM
Stan,
No, I was not basing my statement on 210.23(A)(1).
I was basing it on 210.20(B)(2) and T. 210.20(B)(2).
(2) Total Cord-and Plug-Connected-Load.
"Where connected to a branch circuit supplying two or more receptacles or outlets, a receptacle shall not supply a total cord-and-plug-connected load in excess of the maximum specified in Table 210.21(B)(2)."First off, in my 2008 the Art's you are referring to are 210.21(B)(2) and T. 210.21(B)(2).
You have to remember, a duplex receptacle is two receptacles. So a duplex receptacle on a 15A circuit could theoretically serve two 12A loads. They could just not run simultaneously, for very long at least. ;)
donf
Sep 9, 2010, 08:51 AM
First off, you are correct. The article is 210.21. That's the one I was addressing. I have edited the post to correct it. Thanks!
If you don't mind, if the circuit (20A) services a room with (8) 15A receptacles (using table 210.21) and your explanation, then I would expect that any and all of the 8 receptacles would be allowed to feed up to 12 amps on each connection point, provided that no other receptacle is actively supplying 12 amps to another load.
However, the entire circuit should not demand more than 12 Amps at any one time? Theory or Practice?
stanfortyman
Sep 9, 2010, 11:34 AM
If you don't mind, if the circuit (20A) services a room with (8) 15A receptacles (using table 210.21) and your explanation, then I would expect that any and all of the 8 receptacles would be allowed to feed up to 12 amps on each connection point, provided that no other receptacle is actively supplying 12 amps to another load.Yes, only this would be 16 receptacles, or as you say connection points.
However, the entire circuit should not demand more than 12 Amps at any one time? Theory or Practice?No, it would be 15 amps.
See Table T210.24