Mel’s work plan is as follows:
- Mount 20mm steel conduit horizontally onto the room concrete wall.
- Run an earthing wire from the room lights and mount onto the steel conduit.
- Mount an earthing wire with an alligator clip onto the steel conduit for earthing each drum when they are in use.
Hi Mel, thank you for your excellent question regarding proper grounding for hazardous material storage. Properly bonding metallic components in hazardous storage areas is a vital requirement to ensure proper safety. Differences in potential and static electricity can cause sparks and/or hazardous currents to flow through combustible materials, resulting in fire and/or explosion. It sounds like your project has requirements to eliminate these hazards.
When discussing static control it is important that one understand the difference between “Bonding” and “Grounding” (also known as Earthing), as you will need to do both in order to provide proper protection. Our concern is that simply pulling a ground wire from the existing lights is probably inadequate, and could quite possibly have negative consequences. If some component on the same circuit as the lights were to fault, you could end up forcing hazardous current into your combustible storage room. That would be very bad indeed.
As engineers, we become very concerned about answering questions along these lines as there are simply too many issues to handle via email. Ensuring that you have adequate and effective grounding, that you do not have isolated grounding, and that you have proper bonding between components, is trickier than it you may think. Also, providing a low resistance-to-ground electrode, generally requires on-site testing and computer modeling.
We would highly encourage you to contact an expert in this field to review your project plan. If not us, please consult with someone who understands the nuances of grounding and bonding in hazardous storage areas. Also, please keep in mind that filling and un-filling of combustible chemicals may have additional grounding and bonding requirements.
We hope you find this information valuable and thank you once again for considering E&S Grounding Solutions.
The E&S Grounding Solutions Engineering Team
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