Size Matters (For Fuse and Relay Amp Ratings)
 

I've just installed an auxilary a/c condenser, with a fan. The specs for the fan talk about 6.5 amps *input*. I assume they mean it draws 6.5 amps. My questions are these:

1. What size (amp rating) fuse should I use?

2. What size (amp rating) relay should I use?

Thanks for the help, guys. SmileWavy

If it means the normal draw is 6.5 Amps,.... I think normal convention in the electrical business says load shouldn't be more than 70% of the installed fuse rating. In that case, I'd go for a 10A fuse. To be on the safe side, however, you might want to try a 7.5A fuse and if it doesn't blow..keep that.
Most cube relays are rated at 30A. I like the Bosch, silver-contact cube relays rated at 50A, just "because"...

You canget these from Bosch or Waytek Electric..web page in the archives.
---Wil Ferch

You always fuse for the wire and use wire sized to the load.

Depending on the length of the run a 10amp fuse w/ 14AWG wire. As Will said there is little penalty for using a larger relay.