ST-2D to NCM-300 upgrade

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MarkWeinberg
Posts: 2
Joined: Sat Apr 03, 2021 8:11 pm

ST-2D to NCM-300 upgrade

Post by MarkWeinberg »

]Hi, I have replaced my EWC-ST-2D panel with an NCM-300 and followed the upgrade wiring instructions. I wired the NCM-300 exactly the same as the ST-2D on the system block (see attachements). I have a gas-fired furnace and external AC unit with 2 zones. The reason for the upgrade is to be able to install Nest thermostats. I have not yet installed the Nests, keeping the existing thermostats connected. After turning on the system and having a zone call for heat, the system seems to run as expected, and delivers heat to the correct zone for several minutes. I then hear what sounds like a relay clicking from the furnace and the NCM-300 shuts completely off, as if there was a short, no LEDs. I tried this on both zones and the system acted exactly the same for both. Is there an issue with the way my system is wired?

Thank you,
Mark
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MarkWeinberg
Posts: 2
Joined: Sat Apr 03, 2021 8:11 pm

Re: ST-2D to NCM-300 upgrade

Post by MarkWeinberg »

Refreshing this as I haven't had a response in 16 days.
Steven W.
Posts: 36
Joined: Tue Jun 25, 2019 9:13 am

Re: ST-2D to NCM-300 upgrade

Post by Steven W. »

You have a short. Please give us a call
732-446-3110 x461
Steven R. Weisneck
Technical Engineer
Tel: (732) 446-3110 Ext. #461
www.ewccontrols.com
sweisneck@ewccontrols.com
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