Rating of a switch ??

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ritelec

ritelec

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Jersey
First off. There's a joy to share.
There's a lot of good things in life but hardly anything compares to how one feels when an ice cream headache goes away AND when putting a gfci receptacle in a 1900 cover you're able to start the nut on that very short screw they give you. WHY DO THEY MAKE THAT SCREW SO SHORT!!!


ok.

Switch rating. Is a fifteen amp switch only good up to 15 amps or do you think they give it a little head room
(16-18) ?

Thank you
 
its "rated", whatever the rating is ;)

same switch in a pool of -20F pure water will likely handle many more amps, probably hundreds. there is the issue of arc'ing during siwtching, but you didnt ask about that.

and no worries, we can have have liquid water at -20F, just as we can have boiling water at 10F :lol:
 
Funny you mentioned arc.

Were you following me today.

That's the reason I asked.

I had put a 15 amp switch with pilot light combo device to control an outdoor receptacle. The owner plugged a heat cable into the receptacle and as I turned the switch on and off there is a nice arc in the switch when turning off.

I doubt the cable is pulling more than 15 amps but in my travels I'll stop and see what it's pulling ??
 
ritelec said:
First off. There's a joy to share.
There's a lot of good things in life but hardly anything compares to how one feels when an ice cream headache goes away AND when putting a gfci receptacle in a 1900 cover you're able to start the nut on that very short screw they give you. WHY DO THEY MAKE THAT SCREW SO SHORT!!!


ok.

Switch rating. Is a fifteen amp switch only good up to 15 amps or do you think they give it a little head room
(16-18) ?

Thank you
Click to expand...
Use the screws you pull out of the device:) Longer and easier
 
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GerryB said:
ritelec said:
First off. There's a joy to share.
There's a lot of good things in life but hardly anything compares to how one feels when an ice cream headache goes away AND when putting a gfci receptacle in a 1900 cover you're able to start the nut on that very short screw they give you. WHY DO THEY MAKE THAT SCREW SO SHORT!!!


ok.

Switch rating. Is a fifteen amp switch only good up to 15 amps or do you think they give it a little head room
(16-18) ?

Thank you
Click to expand...
Use the screws you pull out of the device:) Longer and easier
Click to expand...

You're right !!!

I took one apart that was done that way recently and thought what a great idea. The screws from the device weren't as pretty. But I think you're right. Next time the device screws go in ( unless they're the black ones .... Bunk it , blacks go in too. ?)

Thank you !!
 
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About ready to let this post go. but still wondering.. if a 15 amp switch is rated for "15 amps", from what little I understand, "breakers" depending on curves, inrush, and many other terms I don't know about....... a 15 amp breaker can allow greater than 15 amps to run through it for an extended period of time. If there was a 15 amp switch in line with that load, the switch would have to be rated for ( or be able to handle ) more than 15 amps.. right??
 
Like most electrical devices, the rating is really little more than a measure of its ability to dissipate heat - and under the extreme limits of the environment for which it is designed to operate. So it is likely, in the environment of today's perfectly heated and cooled homes, a switch would survive under a continuous load of more than 15 amps. However, how much more there is no way of knowing, because the manufacturers won't tell you that it will do more than it is sold for. Might cut into the sale of their 20 amp models!:)
 
161129-2233 EST

What is a rating? Simply a criteria that something is likely to have some reasonable life, or is likely to be reasonably safe under the rated conditions.

Do you believe that if you load a 15 A rated switch to 15.1 A that it is going to fail? I conjecture I can load that switch to 30 A continuously, and possibly even 60 A at room temperature, and not have it fail. I took a cheap switch and at 10 A the voltage drop was 0.06 V . That is 0.6 W. Do you know how large a 1/2 W resistor is, and how it dissipates heat? So could my switch dissipate 16*0.6 W? 10 W gets to be a lot in a small packge, so possibly not.

A normal wall switch life is more likely based on its life switching a load than its internal temperature rise. This life will be dependent upon the type of load and the amount of arcing. Note that you see a different load rating for a switch switching a resistance vs a motor.

.
 
Standard snap switches are based on the load, not the circuit. If you are running 1000W of lighting on a 20A breaker, a 15A rated switch is fine. and yes, you will see a small arc, just as if you touched the two wires to the switch together manually and there is a load present.

gar said:
161129-2233 EST

What is a rating? Simply a criteria that something is likely to have some reasonable life, or is likely to be reasonably safe under the rated conditions.

Do you believe that if you load a 15 A rated switch to 15.1 A that it is going to fail? I conjecture I can load that switch to 30 A continuously, and possibly even 60 A at room temperature, and not have it fail. I took a cheap switch and at 10 A the voltage drop was 0.06 V . That is 0.6 W. Do you know how large a 1/2 W resistor is, and how it dissipates heat? So could my switch dissipate 16*0.6 W? 10 W gets to be a lot in a small packge, so possibly not.

A normal wall switch life is more likely based on its life switching a load than its internal temperature rise. This life will be dependent upon the type of load and the amount of arcing. Note that you see a different load rating for a switch switching a resistance vs a motor.

.
Click to expand...

A standard snap switch, sure. A 600W dimmer would probably catch fire within a few hours if it had 2400W (4x rated load via your example) loaded on it. I've seen them melt from a 100% overload (1200W (12x100W incandescent lights) on a 600W dimmer).
 
ritelec said:
First off. There's a joy to share.
There's a lot of good things in life but hardly anything compares to how one feels when an ice cream headache goes away AND when putting a gfci receptacle in a 1900 cover you're able to start the nut on that very short screw they give you. WHY DO THEY MAKE THAT SCREW SO SHORT!!!


ok.

Switch rating. Is a fifteen amp switch only good up to 15 amps or do you think they give it a little head room
(16-18) ?

Thank you
Click to expand...

Every product with any rating ever, will have a little bit of headroom on that rating. It will not epically fail at just one unit of loading higher than its rating, because it probably has headroom built in to the testing procedure, so that it is tested at a safety factor above its rating. Such as 150% its rating or twice its rating. What exactly that headroom is, will depend on the type of product you are dealing with, and the exact testing procedure to confirm its published rating.

There also is the statistical nature of manufacturing anything, in that its true failure load will vary among different productions of built to the same design. Some 15A switches might fail at 50A, others from the same production might fail during the same test at 49A or 51A. Part of the safety factor is to account for the tolerance on its true failure rating.

In any case, it is not permissible to design an installation, that depends on this headroom. Stay within its published operational load limit.
 
iwire said:
Take that screw and throw it away, use one of the long 6/32s that are on the device yokes

They are long and tapered so it's easy to start the nut.
Click to expand...
That taper is, I believe, is also thread cutting, so be careful not to cross thread it into the nut. :)

Sent from my XT1585 using Tapatalk
 
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