Nec 210.23 B 1-2 equipment ampacity limit on a circuit

Jpflex

Jpflex

Electrician big leagues
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Electrician commercial and residential
From NEC 210.23 (B)

We know that if a circuit supplies either or both lighting loads, cord and plug utilization equipment not fastened in addition to equipment fastened in place, then the fastend in place equipment cannot exceed 50% of the circuit rating (breaker size determines circuit rating)

If a utilization equipment not fastened in place is hooked to a circuit it cannot exceed 80% of the branch circuit rating

However, if you have fixed in place utilization equipments and no other lighting or cord and plug non fixed in place loads supplied by a circuit, apparently either equipment can exceed 50% of the circuit rating with total load not to exceed 100% of the load.

For example 2 fixed in place appliances on a 20 ampere circuit. One at 19 amperes and the other load at 1 ampere, for 20 ampere total load.

I thaught circuits (breakers) in general were not to be loaded over 80% of their rating but my NEC hand book says:

"The requirement does not apply to a branch citcuit that supplies only fastened in place utilizatiin equipment. For example, a 20 ampere branch circuit that supplies a waste disposer and a dishwasher, neither appliance is restricted to 50% (10 amperes) of the branch circuit rating. The combined load of the two appliances cannot exceed 20 amperes" page 119 nec handbook 2023


i disagree and belueve the circuit should be limited to 20 i amperes x 80% = 16 i amperes
 
Jpflex said:
For example 2 fixed in place appliances on a 20 ampere circuit. One at 19 amperes and the other load at 1 ampere, for 20 ampere total load.

I thaught circuits (breakers) in general were not to be loaded over 80% of their rating but my NEC hand book says:
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The example is correct and permitted by the NEC. Another good example would be a 12 amp dishwasher and an 8 amp garbage disposal. The 80% rating is applicable to continuous loads. If the loads are non-continuous the circuit can be loaded to 100%.
 
LarryFine said:
Depends on whether the loading is continuous.
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Nec 210 23 B 1 and 2 do not mandate whether equipment is a continuous or noncontinuous load.

The code just says the circuit for utilization cord and plug equipment cannot exceed 80% of the circuit rating or 50% for fastend in place equipment on a circuit shared with lighting and or other cord and plug non fastened in place equipment

The nec handbook then says to load up tbe circuit at up to 100% of the circuit rating where only fastened in place equipment are supplied from a circuit. There is no mention or stipulation of continuous or non continuous loads in this code section
 
infinity said:
That is correct.
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So the book leaving out "except for continuous loads" made its code section part false because the whole application of this depends on the type of load being continuous or non continuous.


Nec apparently assumed non continuous loads were being served and made no mention of load distinnction. Nec needs to revise this section or one can dispute the legality or validity of placing fixed continuous loads at 100% of the circuit rating.
 
Jpflex said:
Nec apparently assumed non continuous loads were being served and made no mention of load distinnction. Nec needs to revise this section or one can dispute the legality or validity of placing fixed continuous loads at 100% of the circuit rating.
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No, just because 210.23 is silent on the issue doesn't mean that it assumes there are no continuous loads. The restrictions of 210.23 and 210.19/210.20 both apply. Whichever is stricter will control any particular install.

Cheers, Wayne
 
Jpflex said:
From NEC 210.23 (B)

We know that if a circuit supplies either or both lighting loads, cord and plug utilization equipment not fastened in addition to equipment fastened in place, then the fastend in place equipment cannot exceed 50% of the circuit rating (breaker size determines circuit rating)

If a utilization equipment not fastened in place is hooked to a circuit it cannot exceed 80% of the branch circuit rating

However, if you have fixed in place utilization equipments and no other lighting or cord and plug non fixed in place loads supplied by a circuit, apparently either equipment can exceed 50% of the circuit rating with total load not to exceed 100% of the load.

For example 2 fixed in place appliances on a 20 ampere circuit. One at 19 amperes and the other load at 1 ampere, for 20 ampere total load.

I thaught circuits (breakers) in general were not to be loaded over 80% of their rating but my NEC hand book says:

"The requirement does not apply to a branch citcuit that supplies only fastened in place utilizatiin equipment. For example, a 20 ampere branch circuit that supplies a waste disposer and a dishwasher, neither appliance is restricted to 50% (10 amperes) of the branch circuit rating. The combined load of the two appliances cannot exceed 20 amperes" page 119 nec handbook 2023


i disagree and belueve the circuit should be limited to 20 i amperes x 80% = 16 i amperes
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A lot of electricians taught me the same thing. I always thought that we were limited to 80% of the branch circuit rating. Then someone told me that if they wanted to limit the circuit to 16 amps, they would make a 16 amp breaker. The way that I understand this is: If you have a 20 amp circuit, it can be loaded to 20 amps. (with the exception of continuous loads) 2023 NEC Art. 210.23 (B) is referring to circuits with multiple outlets and the equipment is NOT fastened in place, NOT individual branch circuits. So (B)(1) tells you that the rating of any ONE utilization equipment is limited to 80% 0fthe branch circuit rating. This means to me, and group please correct me if I'm wrong, if I have a duplex receptacle for a residential refrigerator, it would not be an individual branch circuit because someone could plug something else into the other receptacle. (B)(1) would apply here and the refrigerator could not draw more than 80% of the branch circuit rating or 16 amps. But I could utilize the remaining 4 amps for other equipment. This is also reiterated in 210.21 (B)(2) and in Table 210.21 (B)(2).
 
Rick 0920 said:
A lot of electricians taught me the same thing. I always thought that we were limited to 80% of the branch circuit rating. Then someone told me that if they wanted to limit the circuit to 16 amps, they would make a 16 amp breaker. The way that I understand this is: If you have a 20 amp circuit, it can be loaded to 20 amps. (with the exception of continuous loads) 2023 NEC Art. 210.23 (B) is referring to circuits with multiple outlets and the equipment is NOT fastened in place, NOT individual branch circuits. So (B)(1) tells you that the rating of any ONE utilization equipment is limited to 80% 0fthe branch circuit rating. This means to me, and group please correct me if I'm wrong, if I have a duplex receptacle for a residential refrigerator, it would not be an individual branch circuit because someone could plug something else into the other receptacle. (B)(1) would apply here and the refrigerator could not draw more than 80% of the branch circuit rating or 16 amps. But I could utilize the remaining 4 amps for other equipment. This is also reiterated in 210.21 (B)(2) and in Table 210.21 (B)(2).
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To be considered a utilization equipment fastened in place a refrigerator must be bolted down?

Assuming a refrigerator is not fixed in place, yes i agree with you that it cannot draw more than 80% of the circuit, considering that they are nit continuous loads
 
Rick 0920 said:
This means to me, and group please correct me if I'm wrong, if I have a duplex receptacle for a residential refrigerator, it would not be an individual branch circuit because someone could plug something else into the other receptacle.
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No, it's an individual branch circuit until someone plugs something else into the duplex. Which isn't very likely if the duplex is behind the refrigerator. No need to waste money on a simplex receptacle.

Cheers, Wayne
 
Jpflex said:
For example, a 20 ampere branch circuit that supplies a waste disposer and a dishwasher, neither appliance is restricted to 50%
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I for an appliance that is basically motor driven like a disposal or pump I go by 430.53(A), if the full load rating is over 6 amps I put it on a individual 15A circuit.
 
tortuga said:
I for an appliance that is basically motor driven like a disposal or pump I go by 430.53(A), if the full load rating is over 6 amps I put it on a individual 15A circuit.
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6A = 15A (smallest standard OCPD size until the 2023 NEC) / 250% (Inverse Time Breaker factor from Table 430.52). So that's why 430.53(A) has a special allowance for multiple motors not over 6A.

If you had, say, two motors with 8A full load ratings, then you could put them both on a 20A branch circuit per 430.53(B). Likewise if you have one motor rated 7A and another 4A of non-motor load, no problem under 430.53(B) putting them both on a 15A branch circuit.

So "any motor over 6A gets an individual branch circuit" is definitely more restrictive than is required.

Cheers, Wayne
 
wwhitney said:
6A = 15A (smallest standard OCPD size until the 2023 NEC) / 250% (Inverse Time Breaker factor from Table 430.52). So that's why 430.53(A) has a special allowance for multiple motors not over 6A.

If you had, say, two motors with 8A full load ratings, then you could put them both on a 20A branch circuit per 430.53(B). Likewise if you have one motor rated 7A and another 4A of non-motor load, no problem under 430.53(B) putting them both on a 15A branch circuit.

So "any motor over 6A gets an individual branch circuit" is definitely more restrictive than is required.

Cheers, Wayne
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The one time we got red tagged for it was over two decades ago I had wired a GFCI for a sump pump off a general purpose circuit and the motor in question did not have 'separate' overload protection, we pushed back a little but since there are other practical reasons for individual circuits like redundancy, and having to calculate the load on a residential branch circuit leads to post modern looking geometry diagrams dividing up the square footage of rooms served based on the number of general purpose circuits, its simpler to run individual circuits.
 
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wwhitney said:
6A = 15A (smallest standard OCPD size until the 2023 NEC) / 250% (Inverse Time Breaker factor from Table 430.52). So that's why 430.53(A) has a special allowance for multiple motors not over 6A.

If you had, say, two motors with 8A full load ratings, then you could put them both on a 20A branch circuit per 430.53(B). Likewise if you have one motor rated 7A and another 4A of non-motor load, no problem under 430.53(B) putting them both on a 15A branch circuit.

So "any motor over 6A gets an individual branch circuit" is definitely more restrictive than is required.

Cheers, Wayne
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If a motor is over 1 hp i believe it requires separate overload protection in additiom to your inverse time breaker for short circuit current protection.

How would you go about installing this additional protection for motors in residential lots if the motor does not have this protection internally?

I dont see many motors with starters and heaters for overload protection in residential lots
 
Wait so
wwhitney said:
No, it's an individual branch circuit until someone plugs something else into the duplex. Which isn't very likely if the duplex is behind the refrigerator. No need to waste money on a simplex receptacle.

Cheers, Wayne
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WAit so an individual branch circuit would require a single gange single receptacle but can not include one duplex receptacle?
 
Jpflex said:
How would you go about installing this additional protection for motors in residential lots if the motor does not have this protection internally?
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They would most likely be 1HP or less and short-time intermittent or varying duty so 430.33.
 
wwhitney said:
No, it's an individual branch circuit until someone plugs something else into the duplex. Which isn't very likely if the duplex is behind the refrigerator. No need to waste money on a simplex receptacle.

Cheers, Wayne
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Art. 100 DEF. Branch Circuit, Individual - A branch circuit that supplies only one utilization equipment. If you put a duplex receptacle ANYWHERE, I don't think you can truly consider it an individual branch circuit because we have no control of what another person is going to use it for. The definition in the Code did not add anything additional mentioning an inconvenience to accessing a receptacle as an exception. A true individual branch circuit supplies only one utilization equipment. A duplex receptacle would not meet that requirement. I'll stand by this and reference "Charlie's Rule" on this.
 
Rick 0920 said:
Art. 100 DEF. Branch Circuit, Individual - A branch circuit that supplies only one utilization equipment. If you put a duplex receptacle ANYWHERE, I don't think you can truly consider it an individual branch circuit because we have no control of what another person is going to use it for.
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The verb used is "supplies", present tense. So the determination depends on what is plugged in, not what could be plugged in. Charlie's Rule supports my interpretation.

Now if it said "a branch circuit without any provisions for supplying more than one piece of utilization equipment" then I would agree with your interpretation.

Cheers, Wayne
 
I think there is such a thing as the "intent of the Code". Using your interpretation of this, a branch circuit of 4 duplex receptacles in a bedroom is still an individual branch circuit if only a television is plugged in to one of the receptacles and no others are in use. I don't know of many that will agree with you on that. But some may. I will continue my interpretation of an individual branch circuit as a circuit that will supply only one utilization equipment at any one time. I know I'm adding words to this, but this is what I feel is what is the intent of this based on my conversations with many trade professionals and inspectors. As long as there are vague terms in the NEC, many different opinions can apply and be justified.
 
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