Swapping EWC-ST-2E for NCM-300

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Posts: 1
Joined: Mon May 10, 2021 1:25 pm

Swapping EWC-ST-2E for NCM-300

Post by Eddie23 »

Good Afternoon,

I need to swap my current EWC-ST-2E for NCM-300 due to upgrading to 2 Nest Thermostats. currently only 1 Nest works but when I install the second (main unit), nothing works. I found the step by step walkthrough on how to connect the wires from one panel to the next on your website, but my question is, do I have to install the SAS? Since it is actually drilling a hole into the duct, I want to be 100% sure as to not cause damage to the duct.

Thank you.
John B.
Posts: 27
Joined: Fri Mar 13, 2009 8:57 am

Re: Swapping EWC-ST-2E for NCM-300

Post by John B. »


Sorry for the late response...We have had extremely high tech call volume over the last 6 months and have not paid sufficient attention to the forum.

You don't have to use the "SAS" supply air sensor but we highly recommend it. If you decide to install and use it, drill the hole in the supply plenum 18" to 24" away from the cooling and heating coils. That will ensure you don't accidentally damage anything. But the sensor must still be located "before" any zone dampers.
John Brown :geek:
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