Incident Energy Well Above 40 Cal

[The Smashing Electrons]

Hello all

Does anyone know if it is lawful and or safe to switch a CB (with all the enclosure covers on) that has incident energy way over 40 Cal.

An arc flash survey has been done by an outside firm for our plant. There are multiple CB's with red dangerous labels on them.
My understanding is that the blast from the potential explosion will not be stopped by the enclosure covers and an arc flash suit of any rating will not provide protection from the blast.

There also is no way to shut the power off on the line side as the switches are service disconnects from the utility's transformers There are two services that supply power to the plant.

Also we cannot put remote switching devices on the switches because modifications to the manufactures service disconnects will violate the UL listing for the equipment. If there is an incident the manufacture will claim that site modifications we made to the switch and impeded the CB's ability to operate. The only way we could do this is with written permission from the manufacture of the service disconnects. Has anyone done this? Does anyone think a manufacture will agree to having a third party devise placed on there equipment?

This would seem to me to be a violation of OSHA's general duty clause; 29 U.S.C. ? 654, 5(a)1: Each employer shall furnish to each of his employees employment and a place of employment which are free from recognized hazards that are causing or are likely to cause death or serious physical harm to his employees."

Can someone help me with this, the employer seems to think if the enclosure covers are on it can be switched. The life you help save might be mine or one of the other maintenance electricians. :?

 

[petersonra]

Also we cannot put remote switching devices on the switches because modifications to the manufactures service disconnects will violate the UL listing for the equipment. If there is an incident the manufacture will claim that site modifications we made to the switch and impeded the CB's ability to operate. The only way we could do this is with written permission from the manufacture of the service disconnects. Has anyone done this? Does anyone think a manufacture will agree to having a third party devise placed on there equipment?

Who told you this? None of this is generally true.

 

[zbang]

You could get the remote control from the breaker's manufacturer.

There are remote operators that don't attach to the breaker itself. Some have brackets that attach to the switchboard cover, some don't. "ChickenSwitch" comes to mind; search for "remote breaker operator" and "remote breaker racking".

 

[jim dungar]

There is probably a big difference in 'blast' that results from a 40cal/cm? event that occurs withing 3 cycles, and one that occurs because the it takes 3 seconds for a protective device to operate.

You should include a risk analysis as part of your implementation of Arc Flash Incident Energy calculations.

Only your AHJ can 'rule on' a field modification affecting compliance with UL listing standards.

 

[zog]

Hello all

Does anyone know if it is lawful and or safe to switch a CB (with all the enclosure covers on) that has incident energy way over 40 Cal.

An arc flash survey has been done by an outside firm for our plant. There are multiple CB's with red dangerous labels on them.
My understanding is that the blast from the potential explosion will not be stopped by the enclosure covers and an arc flash suit of any rating will not provide protection from the blast.

The best approach it mitigation, recommendations should have been given with the arc flash analysis results.

Also we cannot put remote switching devices on the switches because modifications to the manufactures service disconnects will violate the UL listing for the equipment. If there is an incident the manufacture will claim that site modifications we made to the switch and impeded the CB's ability to operate. The only way we could do this is with written permission from the manufacture of the service disconnects. Has anyone done this? Does anyone think a manufacture will agree to having a third party devise placed on there equipment?

Not sure where you get this from? Anyways, there are remote operators that require no modification to the equipment for just about any device you can come up with.

http://www.cbsarcsafe.com/catalog/

Can someone help me with this, the employer seems to think if the enclosure covers are on it can be switched. The life you help save might be mine or one of the other maintenance electricians. :?

Only if they are arc rated enclosures.

 

[The Smashing Electrons]

Who told you this? None of this is generally true.

Who told you that what I said is not generally true?