Golf Carts Releasing Hydrogen When Being Charged 2

[joerob]

I am currently reviewing a new golf clubhouse which includes a golf cart storage area in the basement. These golf carts are battery powered, and thus undergo re-charging. I know that during the re-charging process, hydrogen gas if given off. The storage area is equipped with a hydrogen gas monitoring system which turns on and exhaust system when the hydrogen level is detected as 20% of the lower explosion limit (lel), and shuts off power to all of the battery chargers and alarms if 40% lel is reached.

In addition to the above, I am considering incorporating the following measures. I feel that the cart storage area should be electrically classified as a Class I, Zone II hazardous location, since failure of the ventilation system could lead to the presence of dangerous level of hydrogen in the area. Additionally, I am considering de-energing all devices in the area if 40% lel is reached, not just the chargers. And finally, all equipment that is to remain operational in the event that 40% lel is reached should be installed in accordance with Class I Zone II requirements, such as the hydrogen detection system, emergency lighting, fire alarm, etc. The remainder of the equipment does not need to be classified for non hazardous areas as it would be de-energized.

Does anyone have any experience with golf cart storage area ventialation and classifications? Do the above measures of using Class I Zone II components seem like overkill since by shutting the battery chargers off, the release of additional hydrogen should be limited, or should all equipment in the area be of Class I Zone II type?

Comments are appreciated.

 

[phoward]

You are certainly on the right track to do it right! I applaud your efforts and hope the owners will buy into it! The "local jurisdiction" (city, county, state fire department or building department) of course should review your proposal, as well as the sophisticated insurance carrier.

You may find that to start with, under the NFPA Life Safety Code, such an expolsive-fire potential will be entirely barred from being in the basement of a building that could be occupied with public visitors of any number at any time. You may have to have a separate building anyway.

The weak point in the system is the hydrogen sensor. What will be the location(s), ambient temp, and moisture, etc. conditions? These chemical sensors have distinct working life and their documented testing would be mandatory in your scenaria, regularly, before the working life and a mandatory replacement before the working life time.

Also, the system shut down will have to be tested regularly, probably monthly. Since it is an emergency system, and once installed, OSHA has regulations on such upkeep, inspections, and testing.

Lastly, OSHA requires an emergency eyewash/shower station within the immediate area for anykind of wet-battery re-charging.

PS It is a pleasure to see a post that is so fully descriptive of the issue. Thanks for making it so easy to get right to the point, so many miss the value of a decent posting of information.