wire size / distance "graph"

SoundGuy wrote:

theoldwizard1 wrote:
I don't like the fact that NEMA allows 5-15 plugs and receptacle to carry 20A loads.

The reason is that the lugs on 15 amp male plugs & receptacles are identical in size and weight to those on their 20 amp counterparts.

NEMA rating has nothing to do with the difference in lug/prong size. It is about the gauge of the wire.

theoldwizard1 wrote:
I don't like the fact that NEMA allows 5-15 plugs and receptacle to carry 20A loads.

The reason is that the lugs on 15 amp male plugs & receptacles are identical in size and weight to those on their 20 amp counterparts.

CA Traveler wrote:
Why is their a difference between 2 vs 3 prong 16 gauge? Insulation type maybe?

Just a guess. The reason could be that the cable used on the far left cord is SVT (sometimes call "vacuum" cord because it is used on vacuum cleaner and other light appliances). Not as "mechanically" robust as SJT or SJOOW.

pianotuna wrote:
Hi,

Of course the cord color varies--but this is a nice quick graphic way to select a good gauge. It appears that the #10 wire is wrongly labeled.

I would like to know what is "wrong" ? Is it that a 10 gauge cord should handle 30A at 50' ? If so, the 20A limit may because the image of the 10 gauge cord is drawn with either a NEMA 5-15 or 5-20 plug. For 30A it would have to be a NEMA 5-30 (fairly odd) or a NEMA TT-30 (common in the RV world).

What I don't like is the on the 12 gauge cord it appears they drew a "locking" plug (NEMA L5-20). I don't like the fact that NEMA allows 5-15 plugs and receptacle to carry 20A loads. NEMA 5-20 receptacle accept NEMA 5-15 plugs. If the load is 20A, IMHO, the plug should be a NEMA 5-20.

The chart that may be misleading and has little to offer. Why would the 10 ga be incorrect when the plug type may be the limiting factor? Why is their a difference between 2 vs 3 prong 16 gauge? Insulation type maybe? The cord cover color has no significance in the US, don't know about Canada. Are the amp ratings even correct?

I'd prefer a chart that shows distance vs voltage drop. I suppose amp draw can be helpful but I suspect that most assume that a 20 amp plug cord can be used - well for a 20A draw, with little consideration for 15A vs 20A rated plugs.

Actually I'd use a wire gauge calculator.

Voltage Drop Calculator at the bottom of the page, AC and DC.
http://www.powerstream.com/Wire_Size.htm