torubleshooting in classified areas

[johnny s]

At our power plant we have some class 2 areas due to the accumulation of coal dust. We installed a new fire protection system that requires routine troubleshooting/maintenance. The terminal boxes where the troubleshooting will take place is located in a Class 2, Division 2 Group F area.

While writing a procedure for this I realized that I have never seen it stated in the NEC or elsewhere that troubleshooting in classified areas while the unit was running is acceptable. We do this all of the time but I would like be able to say I have thought of this and have something in writing to fall back on if the question is ever asked.

Thanks,

Johnny

 

[rbalex]

Do you perform the troubleshooting under some form of permit, such as "hot work" or "enrgized electrical work"? (they aren't quite the same)

 

[gareth0127]

In my oil refinery experience you typically carry out any troubleshooting in conjunction with a "hot work permit" which involves operations carrying out periodic gas testing of the work location. In recent years this has also been carried whilst using a personal 4in1 gas monitor that continually tests for a flammable atmosphere.

 

[K8MHZ]

At our power plant we have some class 2 areas due to the accumulation of coal dust. We installed a new fire protection system that requires routine troubleshooting/maintenance. The terminal boxes where the troubleshooting will take place is located in a Class 2, Division 2 Group F area.

While writing a procedure for this I realized that I have never seen it stated in the NEC or elsewhere that troubleshooting in classified areas while the unit was running is acceptable. We do this all of the time but I would like be able to say I have thought of this and have something in writing to fall back on if the question is ever asked.

Thanks,

Johnny

The NEC does not apply to the inside of power plants.

I worked for a company that installed a fire suppression system on a coal fired power plant boiler. I spent a week installing boxes and connecting terminals and conductors inside those boxes while the boiler was running. It was very hot (over 120) and very dirty (coal dust everywhere) and on top of that, the boxes needed brackets welded to rails and that was also done while the boiler was operating. The only time the boiler was down was when the sensors and water lines were installed which were in the feeder pipes.

 

[mark480]

troubleshooting

troubleshooting

In our waste water plant,we have to fill out a hot permit and maintenance electrical permit for classified areas with incude air testing,You may not have the equipement to cover all that is needed to cover yourself,but at least it`s better then nothing. Good Luck

 

[don_resqcapt19]

The NEC does not apply to the inside of power plants....

The NEC does not apply to utility owned power plants. It applies to other power plants.

 

[K8MHZ]

The NEC does not apply to utility owned power plants. It applies to other power plants.

You are correct. I just assumed that a coal plant would be a utility owned plant.

 

[rbalex]

While the NEC may not directly apply in utilities, the NESC probably does. In such cases as classified locations, check NESC rule 127.

 

[johnny s]

thanks

thanks

Thanks for all of your help. Although the NEC does not officially govern the plant we still use it as a good rule of thumb for electrical installations.

Johnny