On Jan 3, 11:36*am, "bill allemann"
wrote:
I need to run some stat wire well before I'll have an hvac guy involved.
What's the number of conductors and gage that's normally used?
This will be a fairly typical forced air and a/c installation.

thanks, bill

"fairly typical" could mean a lot of things.

Google "thermostat wire" and you'll find things like...

http://www.hometech.com/techwire/tstat.html

18 Gauge Solid Conductor Wire
2 Conductor ("millivolt" heat only systems or damper motor control)
5 Conductor (Standard HVAC systems)
7 Conductor (Typical heat-pump systems)

and...

http://www.electrical-supply.net/pro..._prodID_E_3115

Bulk Wire & Cable: Thermostat Wire
18/6 AWG CL2 Brown Thermostat Wire 250 Ft. Long

and...

http://home.howstuffworks.com/home-thermostat3.htm

Wired
This thermostat is designed for a system with five wires -- the wire
terminations are marked as follows:

RH - This wire comes from the 24VAC transformer on the heating
system.
RC - This wire comes from the 24VAC transformer on the air-
conditioning system.
W - This wire comes from the relay that turns on the heating system.
Y - This wire comes from the relay that turns on the cooling system.
G - This wire comes from the relay that turns on the fan.