If you are using the 2006 breaker board it goes on either circuit breaker panel (not the maxi block) if you use the 2005 board anywhere but the 40 amp slots (the raised part of the board).
Here are the 2006 and 2005 power distribution diagrams (It doesn't appear to cover the fan though)
http://www2.usfirst.org/2006comp/Dra...STRIBUTION.pdf
http://www2.usfirst.org/2005comp/Dra...STRIBUTION.pdf