NEMA L5-30 outlet to any NEMA Y plug servicing two 12A loads?

[ExtraVecchio]

Hi all, long time reader and first time poster here, have found so much valuable information on these forums and would like to thank you all for contributing!

Now to the question:

Service is 3 phase, 4 Wire, 208V

Two 10awg conductors (seperate phases), 10awg neutral, and 10awg ground (shared neutral) running from service panel to dual gang box.

The user would like to service 4 intermittant loads of refrigeration eqipment which has a 12A peak initial startup draw from these two circuits, which at 80% is right at the maximum service for the 10awg.

Would using dual NEMA L5-30 outlets in this box, and a NEMA L5 "Y" or equivalent power conditioner be a permissable way for the user to connect the equipment loads?

I have only seen 20A rated splitters, does anyone know of a rated 30A "Y cable" or splitter that could be effectively used in this situation?

Another thought was to have the L5-30 plug feed a small box with dual 15A overcurrent protection devices each connected to an individual outlet to service the equipment.

Any information or other suggestions, solutions, or approaches are very welcome.


Thank you all again.

 

[alehman]

I've never seen such a splitter, but it may exist. Otherwise, your box idea might work. Are the appliances designed for 15 amp circuits?

The 80% rule applies to continuous load.

 

[itsmoked]

I would not use any splitter as semipermanent.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[EEJaime]

I'm confused. An L5-30 is a 30A, 120V, twist lock receptacle. So are your loads at 120V? If your loads are two compressors at a max of 12A each, then connecting them to a 30A receptacle meets the intent of the code. Your are ok as long as any single load does not exceed 80% of the circuit rating and the total load on the circuit also does not exceed the 80%. However you state:

"The user would like to service 4 intermittant loads of refrigeration eqipment which has a 12A peak initial startup draw from these two circuits, which at 80% is right at the maximum service for the 10awg."

That's when this gets a little confusing. Are you saying that the total of all four loads is 12A peak? Or that each load is 12A peak? Or that if you feed two loads from each circuit, then each circuit will have a 12A peak load? And were you saying that your intent is to use the two twist-lock receptacles to feed a "wye" cord, and then plug two 6 amp loads into the two receptacles on each "wye"? If that is the case, then as long as all your devices and conductors match the circuit rating, then you should be ok, it's just somewhat messy. Would not it be simpler to just install two more receptacles and plug the loads in individually?

 

[ExtraVecchio]

Thank you all for the replies!

The appliances are intended for use on 120v.

To clarify, the loads are each 120v, 60hz, 12A peak. 4 loads total, 2 per circuit, each circuit being a 10awg conductor, with a 10awg shared neutral.

That said, the equipment would have to be powered from a "wye" or splitter cable as you describe as there are only the two conductors to service the outlets and a dual gang box in the present situation.

The equipment uses standard NEMA 5-15 plugs, so ideally I would like to find a rated 30A or (25A?) splitter that would go from the L5-30 to two 5-15.

Another option indicated, was to feed to a small wall mounted boxes, each with additional receptacles and dual 15A overcurrent protection devices. Also considered some sort of power conditioner that would feed from the 30A and provide the equivalent of two 15A circuits.

I'm not sure how to wire up more receptacles to the 10awg feeds and have it meet code when we need a 30A OCPD at the panel. Wouldn't additional receptacles require an in-line OCPD? Please advise if there is a way that this is possible, I'm often confused about 210.19 and where taps are permitted.

Thank you all again!

 

[EEJaime]

Code requires that any device on a 30A circuit be rated at 30A, (See Table 210-21(b)(2)and (b)(3)), because if you put a full 20+ Amp load on a 15 or 20 Amp device fed from a 30 Amp circuit, then that device will burn and the breaker will not trip. So you really can't down-size the wire and devices without the additional OCP you mentioned.

Again, it seems it would be a fairly simple fix. My recommendation would be to remove the locking devices, mount a two gang box over each of the existing boxes. Pig-tail #10's to all the conductors and mount four Nema 5-30R single receptacles, rated 30A, 125V, (Hubbell #9308 or equal). Cut off the 15A plug caps from the four loads and install matching Nema 5-30P plug caps on the loads and plug them in. That would be it.

 

[DonPhillips]

The only hazard I see is the listing of the appliance. It may have been designed with a 20A OCP and could burn up if it faulted on a 30A OCP.

Don Phillips

http://worthingtonengineering.com