Proper wire size and type is essential to proper operation in a HVAC split system to prevent excessive voltage drops and communication issues. All electrical lines, sizing, protection, and grounding must be in accordance with the National Electric Code and local codes.
Recommended wire for the Modbus communication wire:
Communication Wire
It is important to use the correct communication wire to ensure reliable communication between the zone sensor and the HVAC equipment. Trane recommends the following wire supplier and wire type.
Suggested Supplier: Windy City Wire
- Plenum rated P/N: 043005AL
- Non-plenum rated P/N: 108760
Other wire may be used if it conforms to the following physical characteristics:
- Twisted pair (2-conductor) plus shield.
- Characteristics Impedance: 100 and 130 ohms.
- Distributed capacitance between conductors: < 100 pF/m.
- Distributed capacitance between conductor and shield: < 200 pF/m.
- Foil or braided shields is acceptable.
- Wire diameter: 22 to 18 AWG
Recommended wire for the 24 vac power wire
| Wire Size | Maximum Wire Length |
|---|---|
| (Gauge) | Physical distance between Unit & T'stat |
| 22 | 30 Feet |
| 20 | 50 Feet |
| 18 | 75 Feet |
| 16 | 125 Feet |
| 14 | 200 Feet |
WARNING:
Information in this article is intended for use by individuals possessing adequate backgrounds of electrical and mechanical experience and who comply with all federal, state, and local laws, rules, orders, or regulations related to the installation, service, or repair of a heating or central air conditioning product. Any attempt to install, service, or repair a heating or central air conditioning product may result in personal injury and/or property damage. The manufacturer or seller cannot be responsible for the interpretation of the information contained herein, nor can it assume any liability in connection with its use.