General use receptacles on 30amp circuits

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jap

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mbrooke said:
See the attachments here, might be a bit better:



https://forums.mikeholt.com/showthread.php?t=198700&page=3&p=2002586#post2002586
Click to expand...

The plans show standard floor mounted convenience receptacles, which should be a standard 15 or 20a 125v duplex mounted in a floorbox, yet, they are shown being fed by a 2p 30a 230v branch circuit.

So, are they actually 15 or 20a 125v convenience outlets, or, 30a 230v 1ph special purpose outlets?

That's what I mean by "Jacked Up".

JAP>
 
mbrooke

mbrooke

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jap said:
The plans show standard floor mounted convenience receptacles, which should be a standard 15 or 20a 125v duplex mounted in a floorbox, yet, they are shown being fed by a 2p 30a 230v branch circuit.

So, are they actually 15 or 20a 125v convenience outlets, or, 30a 230v 1ph special purpose outlets?

That's what I mean by "Jacked Up".

JAP>
Click to expand...



15 amp 230 volts convenience outlets.

The first set of drawings is for a store in a mall.

The second set is for the panels on the 4th floor feeding business related offices. By special purpose the mean dedicated to computers/cubicles.

Forgive me if the second one caused confusion, I only want to give an example of these 30amp circuits being used.
 
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mbrooke

mbrooke

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LarryFine said:
Then you can't use 5-15 receptacles, you can't plug in the 120v appliances and equipment you mentioned, nor should anything that does accept 240v be equipped with 5-15 plugs.
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Half of them are equipped with a NEMA 1-15 / 5-15 plug so its necessary. Ie:




https://www.ebay.com/itm/Hair-Dryer...955506?hash=item1c9997ef32:g:nkYAAOSwcj1aH96C



https://www.ebay.com/itm/New-220V-4...m33fd3f3787:g:3gIAAOSw-05ZoCT3&frcectupt=true



I don't like it either, granted its not highly likely someone will get a hold of a 120 volt appliance, but it is what it is.
 
kwired

kwired

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jap said:
I've got another theory.

Because the screw terminals are not rated for the larger wire, and, scabbing on a piece of #12 to a #10 to make it happen would be a code violation.

JAP>
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I think if 30 amp circuit were allowed the screw terminals would be designed so they are rated for the 30 amp circuit and at least 10 AWG conductors.

mbrooke said:
The question for me is, will #18 trip a breaker when short circuited.
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Probably in most cases yes. How quickly will depend on conditions. The more 18 AWG you have in the path the more it will limit the fault current, limit it too much and you may not even trip on magnetic function of the OCPD and it will take longer to reach the thermal trip point.

LarryFine said:
I believe that, yes, with typical circuit methods and lengths, a direct short will trip all small breakers at the same rate (for a given brand/type).
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Thermal trip points are definitely different for 15 vs 20 vs 30, but I don't agree that they all will have same magnetic trip point either. QO (and I think Homeline also) has lower magnetic trip for the standard 15 and 20 amp single pole breakers than they have for two or three pole 15 and 20's. If you have a problem load that trips on startup, they do offer a "high magnetic" version of those 15 and 20 amp single pole breakers - main difference is higher magnetic trip setting.

I have seen many times where someone resolved that problem (maybe not a code compliant resolution) of tripping at starting by simply replacing a standard 20 amp single pole with a 30 amp single pole - so they must not have same magnetic trip as the 20 has.
 
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jap

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kwired said:
I think if 30 amp circuit were allowed the screw terminals would be designed so they are rated for the 30 amp circuit and at least 10 AWG conductors.
Click to expand...

Exactly, and 15 and 20a 125v Duplex convenience receptacles (As per the symbol on the drawings) are not, that's my point.


JAP>
 
mbrooke

mbrooke

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jap said:
Exactly, and 15 and 20a 125v Duplex convenience receptacles (As per the symbol on the drawings) are not, that's my point.


JAP>
Click to expand...

They are these:


http://fireflyelectric.com/product/16a-duplex-3-pin-universal-outlet-2/


SE-CA_CCS3045SAT3P.jpg
 
mbrooke

mbrooke

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jap said:
That would be good for a voltage drop scenario if the wire had to be upsized, but, not an allowance to feed it with a 30 amp circuits.


Jap>
Click to expand...

Yup

The issue is the practice is so common that I'm looking for comfort (justification) that its safe.
 
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blkmagik21

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Kennewick
mbrooke said:
That might be it then.


But won't the receptacle itself be protected by overload? I can't see someone plugging in more then 4,600 watts of load let lone approaching that.
Click to expand...

If you had seen what I’ve seen doing service calls you would think differently. I’ve been places with multiple power strips plugged into each other to run like 15 things and a heater on the last powerstrip.


Sent from my iPhone using Tapatalk
 
mbrooke

mbrooke

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blkmagik21 said:
If you had seen what I’ve seen doing service calls you would think differently. I’ve been places with multiple power strips plugged into each other to run like 15 things and a heater on the last powerstrip.


Sent from my iPhone using Tapatalk
Click to expand...

No overload on the power strip?

Point well made however.
 
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jap

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mbrooke said:
Yup

The issue is the practice is so common that I'm looking for comfort (justification) that its safe.
Click to expand...

I don't think you're going to find that comfort on a Mike Holt Electrical Forum.

JAP>
 
romex jockey

romex jockey

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Vermont
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electrician
mbrooke said:
Yup

The issue is the practice is so common that I'm looking for comfort (justification) that its safe.
Click to expand...

maybe this>>
410.62 Cord-Connected Lampholders and Luminaires.



2) Provided with Mogul-Base, Screw Shell Lampholders.
Electric-discharge luminaires provided with mogul-base, screw
shell lampholders shall be permitted to be connected to
branch circuits of 50 amperes or less by cords complying with
240.5. Receptacles and attachment plugs shall be permitted to
be of a lower ampere rating than the branch circuit but not less
than 125 percent of the luminaire full-load current.
Click to expand...

~RJ~
 
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