Will this work as "C" for Nest thermostat
#1
02-07-15, 01:10 PM
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Will this work as "C" for Nest thermostat
So, looking to install a nest in my basement. Currently, heat only, red and white wire. Nest said that this should work, no problem. Inside the box at the boiler where the thermostat wires go, there is a terminal labeled, 24vac, with the word COM under it. Should I run a new wire from that to the NEST. Thanks!
http://i31.photobucket.com/albums/c3...207_154332.jpg
http://i31.photobucket.com/albums/c3...207_154332.jpg
Last edited by sandman512; 02-07-15 at 03:39 PM.
#3
02-07-15, 03:29 PM
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#6
02-08-15, 06:23 AM
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#7
02-08-15, 08:16 AM
Electrical codes in the US specify that with line voltage circuits all green colored wires should be for grounding only. If green is carrying 120 volts then it could be a dangerous surprise for anyone working on it.
The MC cable coming into the box has three wires - black is hot, white is neutral, and they are using the green connected to the NO terminal (Normally Open) which back-feeds the boiler. They should have used a 14/3 type cable that has a red wire added. The Green should be connected to the box for a safety ground at both ends.
Also you can see that the wires are nicked badly where they were stripped which can create a hot spot. Should not be a big issue with a control circuit but still not done right.
The MC cable coming into the box has three wires - black is hot, white is neutral, and they are using the green connected to the NO terminal (Normally Open) which back-feeds the boiler. They should have used a 14/3 type cable that has a red wire added. The Green should be connected to the box for a safety ground at both ends.
Also you can see that the wires are nicked badly where they were stripped which can create a hot spot. Should not be a big issue with a control circuit but still not done right.
#8
02-08-15, 08:23 AM
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At the very least that green wire should have been recolored a different color as green is only used for ground purposes. That should have been a piece of three wire cable where it had white, black, red and green.
#9
02-08-15, 08:29 AM
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Some red (phasing) electric tape on each end wouldn't be a bad idea.
I usually keep black and red on my tool pouch.
I have seen this with 3 phase condensers.
I usually keep black and red on my tool pouch.
I have seen this with 3 phase condensers.
#10
02-08-15, 08:36 AM
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First and foremost, thanks for the replies, I appreciate it. I will have my electrician look into that issue(I don't mess with that stuff). For the STAT, I am going to run some new stat wire and hook up the c wire as instructed. Thanks!!!
