codequestion
Banned
- Location
- MD, USA
Receptacle
- Thread starter codequestion
- Start date
- Status
Look at the last pages in your code book, it will tell you how. You can also go to the NFPA website.
Roger
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
15 amp receptacles on 20 amp branch circuits with most the conditions we currently have has been allowed for a very long time, I don't think it is overlooked it is just not seen as a problem.
Also as mentioned internal components of a 15 and 20 are pretty much the same thing - and many probably are exactly the same.
You have much higher risk of overheating the receptacle if you have a poor connection involved then if you had 20 amps of load through the 15 amp device.
codequestion
Banned
- Location
- MD, USA
How is the cord and plug nema 5-15p of kitchen equipment protected if you install 20 amps breaker and 20 or 15 amp receptacle in commercial kitchen and somehow more than 15 amps but less than 20 amps current is drawn? Fire hazard in long run no?
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electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
Pretty much anything you can think of can happen and be a hazard, however the likelihood of such an event has to be taken into account. To get a code change, you will need evidence and documentation that there is an issue.
codequestion
Banned
- Location
- MD, USA
I have no evidence but it is a likelyhood of happening. It is calculated simple math. Is AHJ going to take that chance?
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kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
How is an 18-2 lamp cord plugged into a 5-15 or 5-20 receptacle on a 20 amp breaker protected?
Been determined those things are acceptable long ago. If you can convince CMP's this ins't good then you are welcome to submit PI to make changes in the future.
winnie
Senior Member
- Location
- Springfield, MA, USA
- Occupation
- Electric motor research
If you have a clock radio plugged into a 15A receptacle, it probably has 18 AWG conductors in its supply cable. And it won't have an egc. Ask yourself how is this protected?
A breaker with a 20A trip rating my permit 25A to flow indefinitely (look up breaker trip curves). Ask how a 20A receptacle is protected.
Code is about _practical_ safeguarding, not perfect protection. Devices are designed with excess capacity (headroom) to accommodate things like production tolerances, and some types of fault are very rare or quickly progress to a detectable fault.
-Jon
A breaker with a 20A trip rating my permit 25A to flow indefinitely (look up breaker trip curves). Ask how a 20A receptacle is protected.
Code is about _practical_ safeguarding, not perfect protection. Devices are designed with excess capacity (headroom) to accommodate things like production tolerances, and some types of fault are very rare or quickly progress to a detectable fault.
-Jon
codequestion
Banned
- Location
- MD, USA
My house checked every duplex receptacle. Duplex Nema 5-15R has 15 amps breaker. Not single one has 20 amps breaker. What about that? Why wasnt 20 amps breaker installed then?
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electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
We should probably not allow the following then:
1. Feeder taps
2. Sum of breaker ratings to exceed panel supply
3. MLO service panelboards
4. Ampacity of SEC sized to load where there are multiple mains.
5. Duplex receptacles
6. The higher protection allowances for motors and transformers.
7. The list goes on.....
codequestion
Banned
- Location
- MD, USA
They should give reason as to why the receptacle code would be allowd if Pl is issued besides say it practical no?
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kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
Your small appliance branch circuits, the laundry, depending on how old the bath and now (at least part of) garage should have had 20 amp breakers. All those can use 15 amp receptacles though unless it is a single outlet on an individual 20A branch circuit.
codequestion
Banned
- Location
- MD, USA
Laudry machine washer draws 10 amps on nema 5-15R with 15 amps breaker. Garage receptacle is 15 amps with 15 amps breaker including kitchen. Now the dry has different receptacle configuratuon not nema 5-15R or 20R but thats on 20 amps breaker.
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kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
I'm not debating what you do have just was telling you what you should have had if it complied with code when installed. Garage thing is recent, bath receptacles - around 20 years now have required to be on 20 amp circuit. SABC's and laundry on 20 a circuit go back to before I was doing this trade, laundry may have been later on but I think the SABC's go back to before most of any of us were in the trade.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
The 15 amp cord cap is on there for a reason, the manufacturer has determined that it is adequate for the load of the equipment. We've been using 15 amp cords plugged into 20 amp circuits for almost a century without problems.
You can submit a PI to the NFPA but IMO it will have no chance of being adopted because you have yet to present any real substantiation for the code change.
codequestion
Banned
- Location
- MD, USA
Whats missing from table 210.2 (B)(2) and table 210.21 (b)(3) is the plug rating. What if plug rating is added?
Whats wrong with loads less than 12 amps to be on nema 5-15R and on 15 amps breaker nema 5-15P plug, loads greater than 12 amps but less than 16 amps on 20 amps breaker but either on 15 amps or 20 amps receptacles with nema 5-20P plug?
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Last edited:
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Codequestion, you seem to be under the impression that the ratings of plugs and receptacles are absolute current limitations, that they operate on the verge of destruction, and any higher current will melt them. They are actually designed to carry their current without any appreciable heating.
Receptacle ratings are actually based on plugs they reject, not on the current-carrying capacity limitations of their conductive parts. Just about every receptacle of a given product line uses the same conductive parts in 15- and 20-amp sizes, and only the face-plate configuration is different
Receptacle ratings are actually based on plugs they reject, not on the current-carrying capacity limitations of their conductive parts. Just about every receptacle of a given product line uses the same conductive parts in 15- and 20-amp sizes, and only the face-plate configuration is different
- Occupation
- Licensed Electrician
And with that clear explanation I think we should end on a good note. Thanks for sharing everbody
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