Sail Switch-air pressure sail switch for duct fan operation.

This switch is great for eliminating the need to wire your Duct Fan directly into
your Furnace possibly voiding a warranty or causing your furnace to fail due to a
wiring error. The sail switch turns your Duct Fan on utilizing the air pressure from
your main blower to engage the trigger on the switch. It is installed in the branch
duct between the main branch and the booster fan. Mount the switch with the
VANE facing away from your main duct (FIG. 1) and when your main blower turns
on the air pressure pushes on the small vane and engages the trigger and turns
the Duct Fan on. When your blower shuts off the air pressure drops thus
disengaging the switch. Be careful not to mount this switch to close to you Duct
Fan as the pressure from the fan may keep the switch engaged even after your
main blower turns off. You wire this switch in line with the Duct Fan and your
power source.