3000W Chinese Gensets Info.
professor95 wrote: EDIT ADDED 45/5/2013- When this thread started in March of 2005, I never expected to see it survive this long or amass the quantity of information that has been shared here. In...
Forum Discussion
I received an e-mail this morning from a forum reader asking for some additional information and clarification concerning grounding of AC generators, or alternators, in respect to RVs.
I am sharing my reply on the forum thinking others may have the same or similar questions.
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It makes no difference where the current originates, from the power company, a generator or even "lightning", electrons will seek out a path to earth ground - or better stated, the place where the greatest difference in potential exists. What you want to do is be sure that you do not provide that current path should a fault occur in an electrical device that you may come in contact with.
Yes, being inside an RV is somewhat like that bird sitting on a power line that does not get shocked. As long as you do not come in contact with ground, you may not be at risk. But, explain that to the family of the now deceased guy who managed to electrify the entire frame and aluminum skin on his camper with a faulty generator that just happened to touch ground and the camper at the same time.
The reason ground rods are galvanized or copper clad is as you suggested - to prohibit corrosion, which can create a high resistance to the flow of electrons.
Ground rods like the one for your home are required by the NEC and/or local codes to be at least 8' feet in length so that we have reasonable assurance that they will at some point contact moist soil. Dirt or sand without moisture is either a non conductor or poor conductor - depending upon the minerals in the soil and the organic content.
If the soil is moist all the way to the surface, it is not necessary to have a ground rod driven down to a distance of 8' to create a safe electrical ground. Under these conditions a 4' rod is usually adequate. The minimum requirment to provide a safe ground would be a one foot long rod providing at least 20 square inches of contact with moist earth. Thus, a contact patch, like a metal plate, can also suffice provided it gives the minimum requirment of 20 square inches (yes, my 4" metal cover is 4" short of this). But, the key idea here is moisture MUST be present in the soil and on the surface for these methods to work.
As to your question about the metal jacks attached on your camper frame providing a safe ground when dropped so as to contact the soil: Yes, they may be adequate providing the above conditions for moisure and contact area are met. But you know as well as I do that in the summer or in regions that have little rainfall sufficient moisture may not be present to make this a good grounding source.
I still advocate the use of a 20 amp ground fault circuit interrupter between the generator and the camper. You can also buy GFCI units rated for 30 ampres at RV supply stores, but these run about $100 each. IMHO, that is a small price to pay for personal safety and affords additional protection with both shore and portable power.
I hope this helps to further explain your question about what constitutes a working electrical gound for RVers.
I am sharing my reply on the forum thinking others may have the same or similar questions.
...................................
It makes no difference where the current originates, from the power company, a generator or even "lightning", electrons will seek out a path to earth ground - or better stated, the place where the greatest difference in potential exists. What you want to do is be sure that you do not provide that current path should a fault occur in an electrical device that you may come in contact with.
Yes, being inside an RV is somewhat like that bird sitting on a power line that does not get shocked. As long as you do not come in contact with ground, you may not be at risk. But, explain that to the family of the now deceased guy who managed to electrify the entire frame and aluminum skin on his camper with a faulty generator that just happened to touch ground and the camper at the same time.
The reason ground rods are galvanized or copper clad is as you suggested - to prohibit corrosion, which can create a high resistance to the flow of electrons.
Ground rods like the one for your home are required by the NEC and/or local codes to be at least 8' feet in length so that we have reasonable assurance that they will at some point contact moist soil. Dirt or sand without moisture is either a non conductor or poor conductor - depending upon the minerals in the soil and the organic content.
If the soil is moist all the way to the surface, it is not necessary to have a ground rod driven down to a distance of 8' to create a safe electrical ground. Under these conditions a 4' rod is usually adequate. The minimum requirment to provide a safe ground would be a one foot long rod providing at least 20 square inches of contact with moist earth. Thus, a contact patch, like a metal plate, can also suffice provided it gives the minimum requirment of 20 square inches (yes, my 4" metal cover is 4" short of this). But, the key idea here is moisture MUST be present in the soil and on the surface for these methods to work.
As to your question about the metal jacks attached on your camper frame providing a safe ground when dropped so as to contact the soil: Yes, they may be adequate providing the above conditions for moisure and contact area are met. But you know as well as I do that in the summer or in regions that have little rainfall sufficient moisture may not be present to make this a good grounding source.
I still advocate the use of a 20 amp ground fault circuit interrupter between the generator and the camper. You can also buy GFCI units rated for 30 ampres at RV supply stores, but these run about $100 each. IMHO, that is a small price to pay for personal safety and affords additional protection with both shore and portable power.
I hope this helps to further explain your question about what constitutes a working electrical gound for RVers.
