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Putting the Wire to the Test

Last Updated: April 9, 2020

Putting the Wire to the Test

Ductless installation involves the use of many materials. But, what’s just as important as our Ductless Line Set?  The Power and Communication Cable! There are some important steps that you need to take when choosing the correct wire for your Friedrich Ductless Minisplit. 

We recommend that all power and communication wire for our J-Series and Floating-Air models be comprised of four, 14 Gauge wires, rated for 600 volts. Of the four, two will be for power, one for communication, and one for grounding. Depending on your local codes, it might be required that the cable be enclosed in conduit if it does not carry the proper UL rating, or be specified as a Power Tray Cable. Contacting your local building or electrical department might help in identifying that your local supply chain carries the proper wire. If a required disconnect switch is needed to be placed near the evaporator head, make sure that the switch is both 3-pole and rated for 600 volts. This ensures that that the switch and wire can both adequately carry the proper voltages between indoor and outdoor units. 

Why so specific on the wire?

Our Precision Inverter compressor has the ability to efficiently scale up and down in 1Hz increments. This tight control of compressor operation is contingent on a contiguous signal between the indoor and outdoor equipment, sometimes relying on .01 VDC for proper information transfer.  

When wiring around florescent or neon lights, we recommend that your wire is shielded! Shielded wire contains a small 22 gauge wire that acts as a drain to EMI and RFI. Make sure only one side of the drain is connected and the other is left disconnected, otherwise you might create an EMI antenna, causing your system to produce sporadic communication errors. 

The wire is just as important as line set, so ensuring the proper wire is used is just as important as using the correct line set. When in doubt of the wire, consult your local building department, or just give the Experts in Air Conditioning a call! 

Safe Journeys, 

Peter Iodaci, Jr . - Director of Technical Management

About the Author | Pete Iodaci

Peter concentrates on teaching proper installation, application, design, and troubleshooting of Ductless and Applied Products. Peter is Director of Friedrich’s Ductless Academy and travels across the US teaching contractors trade tips and secrets on servicing and troubleshooting Ductless products. When not teaching, he is leading the Friedrich Technical Assistance Center with troubleshooting calls and writing technical briefs for Ductless and VRP online blog. Peter holds a Bachelor’s Degree from Rutgers University and a Master HVAC License. He comes to Friedrich with experience in Ductless Split and Unitary Systems, Hydronics, Radiant, Steam, Solar, and Controls.