Disconnect used as a switch

[brother]

I know there is a code for breakers to be listed to be used as a switch for lighting 2008 NEC 240.83(D), but is there a code that limits the use of a Disconnects (200 amp) (fused or non fused) as a common switch? Other than not good practice, and I personally wouldnt use it that way, I cannot find a code violation.

Basically whats happening is a motor disconnect, 'levler' will be used to turn power on during the day and off at night and locked out to keep people from using it. Not sure why they don't just install a simple key switch to prevent this if they don't want others using it.

My question is, is there a code violation here that I am missing?

 

[templdl]

I know there is a code for breakers to be listed to be used as a switch for lighting 2008 NEC 240.83(D), but is there a code that limits the use of a Disconnects (200 amp) (fused or non fused) as a common switch? Other than not good practice, and I personally wouldnt use it that way, I cannot find a code violation.

Basically whats happening is a motor disconnect, 'levler' will be used to turn power on during the day and off at night and locked out to keep people from using it. Not sure why they don't just install a simple key switch to prevent this if they don't want others using it.

My question is, is there a code violation here that I am missing?

Because it can not protect itself it must have a sufficient withstand rating and must be able to make and break the load. As long as it's a load break disconnect switch and you have provided a suitable OLPD upstream I see no issues personally.

 

[GoldDigger]

Because it can not protect itself it must have a sufficient withstand rating and must be able to make and break the load. As long as it's a load break disconnect switch and you have provided a suitable OLPD upstream I see no issues personally.

'Maybe not a realistic fear, but since whoever operates the switch will be "interacting with" the disconnect, is there a need for an arc fault hazard assignment, if not a study? I really do not know much about 70E.
What is the voltage at the switch?

 

[brother]

'Maybe not a realistic fear, but since whoever operates the switch will be "interacting with" the disconnect, is there a need for an arc fault hazard assignment, if not a study? I really do not know much about 70E.
What is the voltage at the switch?

This is a 480 volt load. Not sure about the 70e issues, but it just not a good practice in my opinion to use this type of disconnect with this load as you would a control switch.

 

[iwire]

it just not a good practice in my opinion to use this type of disconnect with this load as you would a control switch.

Based on what?

 

[brother]

Based on what?

On the size of the load and voltage. Why would one want to use a Knife disconnect as you would a snap switch. Switching it that frequently. Would you install one to used in this fashion, when you can put in an inexpensive simple key switch to serve the same purpose?

 

[iwire]

On the size of the load and voltage. Why would one want to use a Knife disconnect as you would a snap switch. Switching it that frequently. Would you install one to used in this fashion, when you can put in an inexpensive simple key switch to serve the same purpose?

Why would you not want to? Seriously, do you see a safety issue in doing so?

It is a switch, it is designed and intended to be used as a switch. In your case it is not even making or breaking a load.

Control switches are not considered to be disconnects, now in your example that may not be an issue but in many cases LOTO requirments require the disconnect be operated each time equipment is serviced or adjusted. In many cases this can happen many times a day.

I have worked in rock crushing plants and an amusement park both were only semi-secure at night so standard practice was to open the circuits with disconect switches and lock them.


To me the only issue here is you are not used to seeing it done so you have decided it is a bad practice when it is actully what switches are made for. Disconnect switches are not installed for emergency use only.

 

[ActionDave]

On the size of the load and voltage. Why would one want to use a Knife disconnect as you would a snap switch. Switching it that frequently. Would you install one to used in this fashion, when you can put in an inexpensive simple key switch to serve the same purpose?

I am trying to understand what is your concern is and I am just not seeing it. I agree with other posts that don't see a problem.

 

[pfalcon]

On the size of the load and voltage. Why would one want to use a Knife disconnect as you would a snap switch. Switching it that frequently. Would you install one to used in this fashion, when you can put in an inexpensive simple key switch to serve the same purpose?

We typically don't use snap switches with 480V loads. We use pushbuttons to start/stop contactors. Disconnects are kind of clumsy and not rated for as many cycles. We like installing Master ON / Master OFF pushbuttons to avoid someone pulling the disconnect during a machine cycle. The disconnects are not always convenient to the operator station. It avoids the operator shutting down more than was intended.