I'm getting ready to install a whole house fan in our home. While the
instructions are fairly straight forward for wiring up the 2 speed switch
that came with it, I'm wanting to add in a wall timer as well. The timer
was made by the same company as the house fan.. It has 4 connections total
on the back..on the back it has a picture of the wiring as 2 terminals on
one side being Normally Closed and 2 terminals on one side being normally
Is lead and neutral coming in on one side (NC) and and lead and neutral
going out on the other side (NO)? If that is the case I'm assuming the
Neutral coming out of the timer runs back to the motor, while the Lead
coming out goes over to the 2 speeed switch where it is wired to the lead
wire then the black and red wires attach to the black and red wires at the
Is a ground wire not involved in installing whole house fans? I'm not
seeing mention of this anywhere in the instructions..I will recheck again to
I have a home wiring book but they only show installing a house fan with the
2 speed switch and they have a separate section on timers but not combined
so I was wanting clarification if someone will assist.
I guess what I don't understand is the fact that other wall timers I looked
at had only 2 terminals...I would think this is just the black or lead wire
coming in and black wire going back out to the motor. Basically a simple
disconnect like a light switch. The White wire (Neutral) would bypass the
timer and wire straight up to the motor.
I'm not understanding why this timer I bought that is designed to be sold
with this model of house fan has 4 on the back instead of the other timers
that had two. Wouldn't just having the black feed coming in and black wire
going out to the 2 speed switch work? What are the other 2 terminals for
then? The white wire (neutral) that's what is throwing me off.
I would think the white would bypass this timer as well...but the other 2
terminals make me think that has to run through it too and that isn't making
sense to me.
I couldn't think of any at first either.
One thing is that when the first set of contacts wears out, if ever,
you can switch to the other set. :)
Or maybe, you could have a light sign that is on when the fan is off.
The sign would say, "Fan is off".
Or there could be something else that someone wants on when the fan is
off, or vice versa
OK, I can't think of one either.
Don't connect your neutral to the timer. Run it straight through to the
fan. The timer that you have will allow you to set the time for the fan to
turn off or set the time for the fan to turn on. I am assuming that you
want to use the timer to limit the hours that the fan will be on. In that
case use the normally open contacts. This means that the contacts are open
without the time being set, but will close and the fan will come on as soon
as you turn the dial. You can use a volt ohm meter to verify this. Have the
load from the timer go to the line on the speed switch.
Thank you! That was the answer I was looking for!
After I got home, I started working on the installation...to my surprise and
appreciation...the house builders had preinstalled the electrical boxes and
wiring for a timer and switch..all I had to do was connect them and go.
Saved me a bundle of time!
Thanks again for the response.
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