Wainert
Member
- Location
- Williston, vt
Hello,
last week I was sent to job to finish up the punch list which included 4 single zone heat pumps listed as not working. After much debate the Hvac team said the issue was with the wirring, with my meter in hand I rang all my lines found all units to be correctly terminated. I then went back to the hvac team said our wirring is correct and left for the day.
The next day my PM called me back to the site, the hvac team now stated it was an issue with the control wire. Just so everyone knows these heat-pumps wirring runs from the apt's panel (2-pole 20amp on 3wire romex) to a disco the roof (N/white wire capped in disco) then the outdoor unit; now another 3wire line returns from the outdoor unit passing back threw the disco to the indoor unit. When I meter for voltage I get 120v L-G, 208 L-L for the supply, now my 3rd "white" wire is the "control line" between my indoor and outdoor unit. When I meter this wire to ground I read right around 120v ac with a fluctuating DC voltage of 4vdc to 68vdc. With this info in hand I called tech support to find what I should be reading; the tech tells me the dc voltage should be fluctuating only to spike of around 27vdc, he tells me I have an induced voltage issue on the control wire.
Now as I stated earlier; I was there for punch list, so the building is complete. I don't want punch holes and pull another wire up three floors to get the same results. Has anyone run into an issue similar to this or have a way to reduce the induced voltage?
This building has 28 apt's total on 3 floors and all other heat pumps are working correctly. The 4 units that are not working are spaced out on different levels. I thank you all for reading and any input you may have!
last week I was sent to job to finish up the punch list which included 4 single zone heat pumps listed as not working. After much debate the Hvac team said the issue was with the wirring, with my meter in hand I rang all my lines found all units to be correctly terminated. I then went back to the hvac team said our wirring is correct and left for the day.
The next day my PM called me back to the site, the hvac team now stated it was an issue with the control wire. Just so everyone knows these heat-pumps wirring runs from the apt's panel (2-pole 20amp on 3wire romex) to a disco the roof (N/white wire capped in disco) then the outdoor unit; now another 3wire line returns from the outdoor unit passing back threw the disco to the indoor unit. When I meter for voltage I get 120v L-G, 208 L-L for the supply, now my 3rd "white" wire is the "control line" between my indoor and outdoor unit. When I meter this wire to ground I read right around 120v ac with a fluctuating DC voltage of 4vdc to 68vdc. With this info in hand I called tech support to find what I should be reading; the tech tells me the dc voltage should be fluctuating only to spike of around 27vdc, he tells me I have an induced voltage issue on the control wire.
Now as I stated earlier; I was there for punch list, so the building is complete. I don't want punch holes and pull another wire up three floors to get the same results. Has anyone run into an issue similar to this or have a way to reduce the induced voltage?
This building has 28 apt's total on 3 floors and all other heat pumps are working correctly. The 4 units that are not working are spaced out on different levels. I thank you all for reading and any input you may have!