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BillyHvac
BillyHvac, Journeyman HVAC Tech
Category: HVAC
Satisfied Customers: 22109
Experience:  Endorsed for unlimited heating, cooling, oil burners, boilers, refrigeration, hydronics
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I have an older Carrier Comfort Zone system running 4 zones.

Customer Question

I have an older Carrier Comfort Zone system running 4 zones. Do you know what type of sensor is inside the remote temperature sensor, Part Number 920077? Is it a thermocouple, RTD, or something else?
Submitted: 1 year ago.
Category: HVAC
Expert:  BillyHvac replied 1 year ago.
hello,
the older vvt are based on dc voltage vs resistance.
Do you have a bad sensor? Have you tried to calibrate via option 3?
use reply
Customer: replied 1 year ago.
I am a controls engineer & deal with many standard types of temperature sensing devices. RTDs, Resistive Temperature Devices use a DC voltage VS resistance. There are more than 20 standard RTD types. My sensors are fine. The problem is with the main programmable 4 zone thermostat. It only works sporadically & requires frequent power cycles to reset it. They are no longer available. Local HVAC guys are more than willing to sell me a replacement system for $4000. I can build my own for a fraction of that. The only unknown for me is the type of remote sensor. I have searched the Net & tried to talk to Carrier. They were unwilling to help. I thought someone this site might know what type of sensor they were.
Expert:  BillyHvac replied 1 year ago.
Is this the system you have at the below link?
http://www.aireclima.com/carrier/pdf/33ZC-1PD.pdf
Customer: replied 1 year ago.
No. I have this one.http://dms.hvacpartners.com/docs/1009/Public/00/920415-3SI.pdf