A question has come up in my line of work as a distribution designer for a local electrical utility provider in that a diesel powered emergency generator with a 300 gallon capacity fuel tank is being installed next to our 150 KVA padmount transformer. I have been advised that the customer's emergency generator must be kept at least 20' from the location of our transformer because of the hazardous location clasification of the diesel fuel tank on the generator. In my line of work as a utility provider we are considered to be the "Authority Having Jurisdiction" and in such have the authority to make decisions above the enforcement of the electrical code but I cannot help feeling that possibly we are making an error in classifying this as a hazardous location and are there by creating an added exspense to the customer in having them move the generator to a new location. Are there any possibly reasons including primary voltages, that special precautions should be considered with this installation and that possibly the generator should be kept 20' from our transformer.
Emergency Diesel Generator
- Thread starter Westar5
- Start date
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Microwatt
Senior Member
- Location
- North Dakota
Haz. loc.
Haz. loc.
What classification are they giving it? Is it just for inside the tank or the whole enclosure? You don't even see explosion proof wiring methods inside the generator enclosures. How could the outside of it have a classification?
Around here the utiliy company wants everything 20' away from their transformers, but I don't think it has anything to do with hazardous locations. Other than the xfmr exploding, which could be hazardous.
I guess I'm confused.
Haz. loc.
What classification are they giving it? Is it just for inside the tank or the whole enclosure? You don't even see explosion proof wiring methods inside the generator enclosures. How could the outside of it have a classification?
Around here the utiliy company wants everything 20' away from their transformers, but I don't think it has anything to do with hazardous locations. Other than the xfmr exploding, which could be hazardous.
I guess I'm confused.
ron
Senior Member
- Location
- New York, 40.7514,-73.9925
Diesel Gens are not generally considered a hazardous location as related to the NEC.
New York Inspector
Member
Utility Clearances
Utility Clearances
Utilities in NY generally requires 10' and that has to do with normal right of way and clearance to their distribution facilities. That increases as you work near transmission facilities.
Utility Clearances
Utilities in NY generally requires 10' and that has to do with normal right of way and clearance to their distribution facilities. That increases as you work near transmission facilities.
See NFPA 37. You'll find no classification is necessary strictly by reason of fuel for the engine. also, diesel is usually stored below its flashpoint.
The issue here is really the transformer and its distance to anything combustible. Less distance to combustible walls, more distance to propane tank relief valves, etc. The xfmr actually has a larger protective radius than diesel fuel because of the oil fire potential. Less distance if you can put up a firewall. Go to the FM Global website look for Loss Data sheet 5-4. Also look at NFPA 850.
BobG
The issue here is really the transformer and its distance to anything combustible. Less distance to combustible walls, more distance to propane tank relief valves, etc. The xfmr actually has a larger protective radius than diesel fuel because of the oil fire potential. Less distance if you can put up a firewall. Go to the FM Global website look for Loss Data sheet 5-4. Also look at NFPA 850.
BobG
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