Upgrading from ST-2E to NCM-300

[ChrisMarshall]

Hello All,

I need some help making sure I have the correct re-wiring before I upgrade my Control Panel from ST-2E to NCM-300. I've attached photos and a wiring diagram for the old and new configuration but have a few (hopefully simple) questions:

1. Where should the 'R' and 'W' wires for the HVAC go to? 'R' to 'RH' or 'RC'? 'W' to 'W2/E' or 'W1/B'?
2. If I'm planning on installing 2 Ecobee 3 Thermostats (one for each of the 2 zones) how should they be configured? Should a wire be repurposed for 'C' to provide power? And what about 'O/B'? I assume I now only need one wire for this? Is there anything else to consider.

Thanks in advance

[ChrisMarshall]

Note: I have tried to attach images but I'm getting the following error:

"Sorry, the board attachment quota has been reached."

Update: Images attached

[Ric]

Please try to repost your images. I've increased the limit.

Ric

[Paul Z.]

Have a few question please call 1-800-446-3110 X490.

[ChrisMarshall]

Hi. I’m attempting this again. Would it be possible to call again as I’m still not certain about switching some of the wires. Thanks.