Im not one of those people that say, use the search function, this has been beat to death, asked so many times...blah blah blah. I hate it when I ask a question and people do that to me.
There is a thread a couple pages back where this is discussed thoroughly. Here's the link, you may have to copy and paste it as I don't know how to make it clickable.
http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/28801857.cfm
The general thinking with this issue is it varies from manufacturer to manufacturer. You'll have to see if the one you have is approved for it.