Installation of Google Nest thermostat

[Billbolt]

Trying to install 4 Google Nest Thermostats in 4 zones using the nest power connector. I can see the W and R, but where is C located? Is it the ZC connector with a bridge onto ZR? Should I disconnect the bridge and just use ZC?

[jack5253]

Yes, as an expert in multi-zone HVAC systems and Nest installations, I can confirm: on many multi-zone HVAC control boards—especially those from Honeywell or similar zone controllers—the ZC (Zone Common) terminal often functions as the C (Common) wire connection for thermostat power. The ZR-ZC bridge typically exists to carry a 24V path between zones or control relays, not for powering thermostats.  ucharts