Wiring Diagram

Jamie_6

How would you guys go about wiring W2 on this diagram. The problem is that the Taco zone control has 24 v coming out of it & the Honeywell control already has 24 v going to the one side of W2.

Thanks for the help,
Jamie

JimGPE_3

My myopia....

I can't read the diagram, but I am assuming W2 is the second stage heat terminal on the thermostatic device, and it gets 24vac from "R" on the thermostat when it is calling for second stage heat.

In addition, the thing that is providing the second stage heat has its own source of 24vac, which you, wisely, figure can't be mixed with the t'stat 24v.

The heating device requires a "dry contact" closure, not voltage, to make it go.

If my assumptions are correct, use the W2 voltage to pull in a 24vac relay with normally open contacts. Use the normally open contacts (dry contacts) to "make" the circuit on the heating device. The relay coil is wired to W2 and C on the thermostatic device.

Voila.

Mark A. Custis

KISS

Nice bit map , but I can not read what terminal is being fed by the blue line from T? throught the coil from T? from W1 on the control board.

Take W2 to the Taco Zone Control and back to common? What's up? I need more input.

What is the Engineer trying to do?

Help is on the way. Just ask the Master

Mark

JimGPE_3

Upon further review

I got your bmp blown up.

If your first stage heat needs 24V from the W8900, it ain't gonna work as you've wired it. You have both terminals tied to Rh. You should go from Rh on the 8900 through W1 to the Wirsbo, then from the other Wirsbo terminal to C on the 8900, not Rh.

Now for the second stage, wire one side of the holding coil of a 24V relay to C on the 8900. Wire the other side of the coil to W2 on the 8900. Wire the normally open contacts of the relay to T and T on the Taco zone control ASSUMING, as you implied, that the Taco has its own voltage source and will light up if you short between T and T.

There.