NEC requirements, Outlet Devices ? Receptacle

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Rob_009

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Can a NEMA 14 50R receptacle (Rated 125/250V, 50A) be supplied by a 120/208v source and still be code compliant? I reviewed NEC 210.21 which imposes Ampere rating requirements, but doesn?t address voltage.

Background: this receptacle is for a piece of moveable equipment (cord and plug) that has been wired to use a NEMA 14 50R receptacle. The equipment is a specialty trailer with only 120V loads.
 
Rob_009 said:
Can a NEMA 14 50R receptacle (Rated 125/250V, 50A) be supplied by a 120/208v source and still be code compliant? I reviewed NEC 210.21 which imposes Ampere rating requirements, but doesn?t address voltage.

Background: this receptacle is for a piece of moveable equipment (cord and plug) that has been wired to use a NEMA 14 50R receptacle. The equipment is a specialty trailer with only 120V loads.
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I believe if the voltage is "equal to" or "less than" the device then there is no issue.
 
A year or so ago I saw a 240/139 volt system with several 125/250 volt 3 wire, 50 amp receptacles in a testing facility. Guess the installer didn't realize that the use of those devices would be a violation.
 
infinity said:
A year or so ago I saw a 240/139 volt system with several 125/250 volt 3 wire, 50 amp receptacles in a testing facility. Guess the installer didn't realize that the use of those devices would be a violation.
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the nominal voltage was 139 ?
 
nakulak said:
the nominal voltage was 139 ?
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The system was fed from a Leibert power conditioner (240Y/139 volt output) in order to provide 240 volts for a testing facility. Seems that the engineer originally spec'd only 240 circuits. Somewhere along the way the design changed to 120/240 circuits to test electric ovens and ranges. No one figured out that the real voltage was 139 volts from the phase to the grounded conductor and all 125/250 volt devices were installed.
 
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