Switch

[jonny1982]

I know that it is ok to put a 15A rec. on a 20A circuit as long as more than one place to plug into. Is it ok by code to put a 15A light switch on a 20A circuit? Please site articles.

Also, has anyone heard that there may soon be an adendum to 210.21(B)(3) stating thatonly 20 amp rec. be installed on a 20 amp circuit?

Thanks

 

[augie47]

I know that it is ok to put a 15A rec. on a 20A circuit as long as more than one place to plug into. Is it ok by code to put a 15A light switch on a 20A circuit? Please site articles.

Yes, Load permitting See 404.14

Also, has anyone heard that there may soon be an adendum to 210.21(B)(3) stating thatonly 20 amp rec. be installed on a 20 amp circuit?

Thanks

 

[Dennis Alwon]

I have not heard about that addendum and I seriously doubt that will happen.

Not sure you will find an article that permits a 15 amp switch on a 20 amp circuit but the NEC is a permissive code and if it doesn't state that you can't then you can. Think of it this way-- why would you need a 20 amp switch if the load on the switch is less than or equal to 15 amps. If you have a 20 amp load on the switch then you would need a 20 amp switch

 

[jonny1982]

I have not heard about that addendum and I seriously doubt that will happen.

Not sure you will find an article that permits a 15 amp switch on a 20 amp circuit but the NEC is a permissive code and if it doesn't state that you can't then you can. Think of it this way-- why would you need a 20 amp switch if the load on the switch is less than or equal to 15 amps. If you have a 20 amp load on the switch then you would need a 20 amp switch[/QUOTE

What if the load changes after the initial install? You think all electricians are going to check the switches and make sure they are rated for 20 amps if they tack on some lights to a switched light loop? A respectable one would, but not all. A great deal of the code is in place because of the idea that future expansion may occur. This is my line of thinking anyway. I always thought that section of 210.21(B)(3) was odd and kind of goes against all kinds of other rules. Just my opinion I guess.

 

[Dennis Alwon]

I have not heard about that addendum and I seriously doubt that will happen.

Not sure you will find an article that permits a 15 amp switch on a 20 amp circuit but the NEC is a permissive code and if it doesn't state that you can't then you can. Think of it this way-- why would you need a 20 amp switch if the load on the switch is less than or equal to 15 amps. If you have a 20 amp load on the switch then you would need a 20 amp switch[/QUOTE

What if the load changes after the initial install? You think all electricians are going to check the switches and make sure they are rated for 20 amps if they tack on some lights to a switched light loop? A respectable one would, but not all. A great deal of the code is in place because of the idea that future expansion may occur. This is my line of thinking anyway. I always thought that section of 210.21(B)(3) was odd and kind of goes against all kinds of other rules. Just my opinion I guess.

We don't live with "What if's". What if the electrician adds more circuits and overloads the circuit? What if the electrician takes a 6 disconnect rule on a service and adds a 7th disconnect?

The NEC is not supposed to be a design manual although it does tend to do just that at times. It is up to us to design a safe system. Now if you feel more comfortable with a 20 amp switch then go ahead and do that. I can say that I have done many many homes with 20 amp circuits and 15 amp devices and never had an issue.

 

[Dennis Alwon]

Check this out

90.1 Purpose.
(A) Practical Safeguarding. The purpose of this Code is
the practical safeguarding of persons and property from
hazards arising from the use of electricity. This Code is not
intended as a design specification or an instruction manual
for untrained persons.

 

[jonny1982]

We don't live with "What if's". What if the electrician adds more circuits and overloads the circuit? What if the electrician takes a 6 disconnect rule on a service and adds a 7th disconnect?

The NEC is not supposed to be a design manual although it does tend to do just that at times. It is up to us to design a safe system. Now if you feel more comfortable with a 20 amp switch then go ahead and do that. I can say that I have done many many homes with 20 amp circuits and 15 amp devices and never had an issue.

Homes yes, but how do you feel about that rule with commercial and/or industrial settings?

 

[mwm1752]

:happyyes:Its either compliant or non compliant - code is minimum - feelings are for the wife

 

[Dennis Alwon]

Homes yes, but how do you feel about that rule with commercial and/or industrial settings?

Since the general rule in commercial is 20 amp switches my tendency is to use 20 amp switches but the code does not require it-- I bet it is more the engineer that calls out 20 amp devices but I am not certain of that.

Think about an office that has 3 or 4 lay in fluorescents-- does it really need a 20 amp switch?

 

[jonny1982]

Since the general rule in commercial is 20 amp switches my tendency is to use 20 amp switches but the code does not require it-- I bet it is more the engineer that calls out 20 amp devices but I am not certain of that.

Think about an office that has 3 or 4 lay in fluorescents-- does it really need a 20 amp switch?[/QUO

I guess I look at it this way. Take a 20 amp circuit. There is 12-2 romex landed on the breaker. The 12-2 comes off the breaker an goes in and out of a junction box. Also comming out of the junction box is a 14-2 romex going to a load that is under 15 amps. Is that legal because I know the load the 14-2 is for is well under 15 amps?

 

[Dennis Alwon]

Since the general rule in commercial is 20 amp switches my tendency is to use 20 amp switches but the code does not require it-- I bet it is more the engineer that calls out 20 amp devices but I am not certain of that.

Think about an office that has 3 or 4 lay in fluorescents-- does it really need a 20 amp switch?[/QUO

I guess I look at it this way. Take a 20 amp circuit. There is 12-2 romex landed on the breaker. The 12-2 comes off the breaker an goes in and out of a junction box. Also comming out of the junction box is a 14-2 romex going to a load that is under 15 amps. Is that legal because I know the load the 14-2 is for is well under 15 amps?

I understand your point but why would 15 amp receptacles be allowed on a 20 amp circuit. It is for the same reason. Generally the load on any one receptacle will not be that great.

The install with a 20 amp circuit and 14/2 going to the load is strictly not permitted. The 15 amp switches are allowed on a 20 amp circuit. Also your example of the 14/2 is very different because now you are depending on a 14 awg wire to clear a ground fault on a 20 amp circuit. That is very different

 

[jonny1982]

Since the general rule in commercial is 20 amp switches my tendency is to use 20 amp switches but the code does not require it-- I bet it is more the engineer that calls out 20 amp devices but I am not certain of that.

Think about an office that has 3 or 4 lay in fluorescents-- does it really need a 20 amp switch?[/QUO

I guess I look at it this way. Take a 20 amp circuit. There is 12-2 romex landed on the breaker. The 12-2 comes off the breaker an goes in and out of a junction box. Also comming out of the junction box is a 14-2 romex going to a load that is under 15 amps. Is that legal because I know the load the 14-2 is for is well under 15 amps?

That aside though, don't you think it's safe to say that the general rule of thumb for commercial or industrial settings is use 20 amp outlets for 20 amp circuits and 20 amp switches for 20 amp circuits? Would you agree that there is code and then there is good practices and that using 20 amp devices in a non residential setting is good practice, or do you think it's a waste of money?

 

[Dennis Alwon]

That aside though, don't you think it's safe to say that the general rule of thumb for commercial or industrial settings is use 20 amp outlets for 20 amp circuits and 20 amp switches for 20 amp circuits? Would you agree that there is code and then there is good practices and that using 20 amp devices in a non residential setting is good practice, or do you think it's a waste of money?

Read my post above yours.

I think it is a waste of money in a residential setting. I have worked on hundreds of homes and rarely is there a device failure due to overload. Not sure I have seen it happen-- loose connection yes but not overload. Also the worst that can happen is the device breaks-- no biggie

 

[infinity]

I guess I look at it this way. Take a 20 amp circuit. There is 12-2 romex landed on the breaker. The 12-2 comes off the breaker an goes in and out of a junction box. Also comming out of the junction box is a 14-2 romex going to a load that is under 15 amps. Is that legal because I know the load the 14-2 is for is well under 15 amps?

That is explicitly prohibited by the NEC so you're not making an apt comparison. As Dennis stated a 15 amp switch is permitted on a 20 amp circuit providing you don't exceed 15 amps of load on that device.

 

[jonny1982]

That is explicitly prohibited by the NEC so you're not making an apt comparison. As Dennis stated a 15 amp switch is permitted on a 20 amp circuit providing you don't exceed 15 amps of load on that device.

Yes, there is absolutlely no argument that 14-2 on a 20 amp circuit is prohibited and a 15 amp device on a 20 amp circuit is. My point is that I have always thought it to be odd that a 15 amp device is allowed on a 20 amp circuit.

 

[infinity]

Yes, there is absolutlely no argument that 14-2 on a 20 amp circuit is prohibited and a 15 amp device on a 20 amp circuit is. My point is that I have always thought it to be odd that a 15 amp device is allowed on a 20 amp circuit.

I can see your point regarding a switch but the NEC is full of what-if scenarios for the next guy who comes along. A 15 amp recpetacle isn't really a problem on the 20 amp circuit because its 15 amp configuration will limit the load to 15 amps.

 

[jonny1982]

I can see your point regarding a switch but the NEC is full of what-if scenarios for the next guy who comes along. A 15 amp recpetacle isn't really a problem on the 20 amp circuit because its 15 amp configuration will limit the load to 15 amps.

Understood. So may I ask what your personal opinion is on 15 amp rec. or switches being used on a 20 amp circuit in a commercial setting. I know code says it's ok, but just trying to get a general consensus.

Thanks

 

[ActionDave]

Understood. So may I ask what your personal opinion is on 15 amp rec. or switches being used on a 20 amp circuit in a commercial setting. I know code says it's ok, but just trying to get a general consensus.

Thanks

A spec grade 15A recpt is 20A recpt guts without the extra notch in the plastic so there is nothing to be gained by using them. We use CR20's on commercial jobs but only because they are cheaper to purchase than CR15's.

There are so few general lighting switches that see anywhere near 10A of load. Most all the lighting is controlled by contactors, time clocks and relays, or just the breaker so I don't see any reason for 20A switches as a general requirement.

 

[jonny1982]

A spec grade 15A recpt is 20A recpt guts without the extra notch in the plastic so there is nothing to be gained by using them. We use CR20's on commercial jobs but only because they are cheaper to purchase than CR15's.

There are so few general lighting switches that see anywhere near 10A of load. Most all the lighting is controlled by contactors, time clocks and relays, or just the breaker so I don't see any reason for 20A switches as a general requirement.

There is just one more point I would like to make about using only 20 amp devices on a 20 amp circuit. When working for a big company, it might become good practice to stick with this because there are so many jobs and so many different hands involved. You say rarely does lighting loads exceed 15 amps or something plugged into an outlet exceed 15 amps meaning it could happen, right? So if you can get the 20 amp devices for the same price or even less than the 15 amp devices, why not just stick with 20 amp devices only on a 20 amp circuit as a rule of thumb just to cover your ass for that one time when load is exceeded?

 

[iwire]

Understood. So may I ask what your personal opinion is on 15 amp rec. or switches being used on a 20 amp circuit in a commercial setting. I know code says it's ok, but just trying to get a general consensus.

Thanks

It is not something I worry about at all.

When I buy switches to stock in the service van I get 277 volt rated ones and those seem to be 20 amp by default.

If it is a construction job the job specifications will tel us what rating the switch is required to have. If the specs say 15 amp then that is what I will use.