Senior Tech Team
Join Date: Jan 2005
Location: Granite Bay, Ca.
Re: Why use a relay on a dual elec fan?
The switch wire size is not especially critical, the relay control coil will draw an insignificant amount of power. However you should also consider the size of the power supply fuse when deciding on what size wire to use. You want to make sure that the fuse blows before any of the wires downstream smoke.
As to relay location, they can be near the power source or near the power consumer (fans) or anywhere in between. Generally just put them where it is convienient and you don't create a significantly longer wire run.