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Wire Voltage Rating

We recently caught a purchasing error in production. 300V wire was accidently purchased instead of the specified 600V rated wire. This wire is used to connect a 3 phase 480V motor to a combination starter.

After this occurred I tried to figure worst case scenario but am having trouble. If a single line voltage is 277 to neutral, is the 300 volt wire okay in this case?

If line to line is 480V, wouldn't two 300V wires really be 600V protection from conductor to insulator (for line 1) to insulator to conductor (for line 2)?

Reply to
Bobd
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277v is bit close for comfort isnt it, what is the maximum the line to earth can go to under fualt conditions ? ie floating nuetral, short from line to nuetral and or line not conected to source etc?

I'm not familiar with practice regard to specifiying cable voltage ratings with regard to safety factor/derating for curent/temp/being enclosed etc.

so I wouldnt be very happy to sign the aceptance.

Colin =^.^=

Reply to
colin

This line of inquiry may be beside the point.

What material does your UL file's constructional data sheet state is to be used?

Similar UL wire styles with differing voltage listings differ usually in one significant physical feature - the thickness of the insulation layer. It may be acceptable to sleeve the erroneous material to meet constructional data statement wording - check with your liason officer for the file in question.

This won't save you any money, but might allow deadlines to be met.

RL

Reply to
legg

277 volts is the RMS line voltage not the Peak which is 277 x 1.414 = 391, so your 300volt insulation is not satisfactory for one line to ground under good conditions.

Sack the specifier and buy the correct wire, is the only good advice.

--
John G

Wot\'s Your Real Problem?
Reply to
John G

Nah, don't sack him - do the fix, and take the cost out of his paycheck. >;->

Cheers! Rich

Reply to
Rich Grise

Oh, my! I thought 600V wire was required for 120V service. It seems someone unloaded stuff they couldn't sell. Well, just hook two wires in series. ;-)

--
  Keith
Reply to
keith

I spoke to a UL person today. He told me 300V and 600V wire are tested the same if it has the AWM (Appliance Wire Manufacture - i believe) mark. Both are subjected to a 2000V dielectric test!

Reply to
Bobd

Is the UL person OKing the substitution?

RL

Reply to
legg

NO. If it is labelled 300 volts then thats the evidence that will be used against You when there is a fatality.

--
John G

Wot\'s Your Real Problem?
Reply to
John G

If there's any accident insurance & criminal justice will likely look at the rateing. Not that the cable happends to be the same as the 600V version.

Useing it is like playing poker..

Reply to
pbdelete

and thats really the only way to look at it.

Cheers Terry

Reply to
Terry Given

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