Do I need to relay an H4 light conversion?

[rhock99@epix.net (Ryan H)]

I would like to try out an H4 bulb and lens I got, just to see how the lighting compares.  It is a three wire bulb, so should I just hook it to the low beams and use all three of the connections in the factory harness? (the stock sealed beams only use two out of the three).  Most importantly, do I need to relay it somehow, or will it be ok as is?
If I need to relay, any links showing the proper way?  I know there was one somewhere out there... 
Thanks!