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15 amp vs 20 amp difference?

Been wondering about this for a while, some power conditioners (Shunyata in particular) and other equipment spec. to use a 20 amp power cord. What is the physical difference between the two? Would the plugs for iec and male input be different and not fit into the regular outlets (ie like the Oyaide GXS or PS Audio Ultimate or do they require a different type specifically just for 20 amp usage? I do realize the amp rating (that they'd draw) between the two would be different. Your help would help to further edudate me, Thanks.
rsjm80
rodman99999
6,035 posts
 
I've never actually seen a 20A audio power cord with a true 20A plug. I just recently bought a 20A ZU Mother, and it had a 15A Wattgate plug.
jea48
4,324 posts
 
Shunyata Research equipment is UL/CSA Listed. Beings they use 20 amp receptacles they have to use a 20 amp IEC male connector to get the UL seal of approval.

For some reason a power cord with a 20 amp IEC connector and a 15 amp plug is ok with UL..... That one doesn't make any since to me. By allowing the configuration it is not idiot proof. Nothing prevents a user from plugging loads designed for a 20 amp branch circuit into a 15 amp branch circuit.....
Jim
inline_phil
11 posts
 
The issue lies in the wiring in the walls. The NEC specifies that the temperature of a wire cannot exceed a certain threshold when the maximum current is continuously used. This is specified to prevent electrical fires occuring inside of your walls from an overheated wire. So the breaker is then matched to the wire as are the outlets (here a 15A circuit). For this reason, changing the outlet to a 20A is risky without also changing the wiring from the breaker box to that outlet.
jea48
4,324 posts
 
For this reason, changing the outlet to a 20A is risky without also changing the wiring from the breaker box to that outlet.
Inline_phil
And that is why NEC says a 20 amp receptacle shall not be installed on a 15 amp branch circuit.....

sleepysurf
121 posts
 
Hah! I just received a Running Springs Mongoose 20A cord, and noticed it has the exact same pairing as the Shunyata and Zu referenced above... a 20A IEC connector, but a 15A rated standard plug! I thought it might have been a production error, but I guess not. Interesting!
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