How Do Communicating Systems Work?
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- Опубликовано: 12 дек 2023
- Join hosts Bryan Orr, Adam Mufich, and Matt Bruner as they answer the question: How do communicating systems work in HVAC? They explore the world of communicating HVAC systems with special guest Steve Cook, National Manager for Technical Operations Training at Hisense.
In this informative livestream, they break down the basics of how modern communicating equipment works compared to traditional 24v systems. Steve shares his deep expertise on topics like communication protocols, wiring best practices, troubleshooting strategies, addressing, and more.
You'll learn:
The core purpose and benefits of communicating systems over standard 24v
An overview of common communication protocols and how they differ
Wiring tips like proper gauge, connections, shielding, and grounding to set up systems for success
How automatic addressing works and why it matters for large-scale installations
How to approach troubleshooting, even on unfamiliar systems, using base diagnostic skills
And much more about the nature of modern HVAC communication
Whether you're just getting started working with communicating equipment or you're a seasoned pro, don't miss these clear, actionable insights from some of the best minds in HVAC education. The future is filled with these advanced controls and sensors, so add this video to your playlist to stay ahead of the curve.
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Great stuff guys, good to see someone demystifying communicating systems. It would be great to see more of these especially with some real practical applications. Common communicating system faults and how to diagnose/address them, best practices for installing communicating systems, etc. As a supervisor I've only had one guy who truly understood and wasn't extremely intimidated by communicating systems.
Great video as always. You’re doing the lords work Bryan
Great discussion and info. Thank you Bryan and guest.👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍.
Great. Looking to see a video that how you set up and troubleshoot a particular equipment
Daikin requires unshielded stranded wire. Stranded wire allows more surface area for the digital signal to travel on the wire, because the pulses are carried on the skin of the wire. DC current is carried in the center of the wire. This is known as "skin effect."
Never heard of this but it mates sense
WhT benefit is unshielded wire giving
Why does it NEED to be unshielded?
@spenceryelinek4313 Shielded cables can create ground loops if the shielding is connected on both ends. Ground loops can interfere with communications both internally and externally. A twisted pair on a balanced line usually doesn't have such problems. If there useing "differential signaling," the likelihood of any interference is greatly reduced.
Thanks for the information
How does the communication voltage protocol say between a Mitsubishi HyperHeat/Intell-Sense unit mounted on top of a high efficiency Daikin furnace? Or any other communicating furnace manufacturer for that matter. Is there some sort protocol converter to translate between the two different systems?
Shielding comm cables makes life easier.
good Lord that guys voice Steve was putting me to sleep I could barely make it to the 15m mark
I wish I'd caught this stream live.
The best question was....What's it all going to do for me in reducing costs thru increased efficiency?
Did anyone present a cost-benefit analysis for a residential system?
Most of this seems to be well past the point of diminishing returns.
Most of it is. But the technology will be widespread in residential applications in the future. Think of it like being the amongst the first of people who owned a computer😜
At the end of the day it's a really cool technology that will lead to a more comfortable house (when houses are properly built / ducted)
And reasonable repair parts. In the appliance business they are out of hand in poor quality/shirt shelf life. High costs for repair parts.
In HVACR think about variable speed motor/module replacements in typical wage earner households.
Well made crimp connections are fine, wire nuts are the problem because there's only about 13 % of the wire making contact.
I dont know if you guys see these comments. I was hoping to get information in the eev. Do you think you could address this in your next stream?
Lennox requires shielded wires against electromagnetic interference
As an electrician learning HVAC systems I understood everything that Steve Cook was saying but man he did not do a good job simplifying it. To anyone still struggling with what he is saying:
Imagine you and 20 strangers wake up in a dark room blindfolded. How do you communicate?
1)You need to identify each person.
2) Everyone needs to speak the same language or its not going to work.
3)If there is a loud background noise even if just two people are talking its going to be SUPER hard to talk to each other and you may only hear every other word
4) If everyone is speaking at the same time it will be really hard for anyone to communicate.
In communications, as he mentioned, these systems are working on low voltage as small as 5V to signal the other components. So the first thing you need to do when installing or troubleshooting a system is
1)IDENTIFY all of your components I.E. make sure each device is addressed. Some systems do not auto address and you may have dip switches.
2)Make sure all of the components are COMPATIBLE with each other
3)Is there something introducing STRAY VOLTAGES into the wiring of the system. Faulty power supply, improperly connected or grounded wire, broken shield, if you had long wiring runs was the wrong wire used?
4)Is there a FAULTY COMPONENT throwing the system into fault.
As they mentioned communications wire needs to be handled a little more carefully. Do not pull across sharp edges, do not pull it too hard, do not run it next to high voltage that can induce stray voltage into your wire ESPECIALLY if it is not shielded and avoid kinking the wire.
Super simple when you stop worrying about WHAT the signal is saying and more WHERE that signal is going or NOT going.
Technicians in my area struggle with multistage wiring. Unless the communicating system is as easy to setup as a single stage there are likely to be more poor installations than quality.
The best bet to solve this nut would be for this industry to form a consortium where they decide on what standards to use. Honeywell should be part of this because of their experience with DCS and Fieldbus.
Expecting most HVAC technicians to be control experts is misguided. They need to be able to make metal ducts, braze and handle other equipment.
Instrumentation and controls are always last when it comes to equipment installation. Techs are generally doing the bare minimum to finish the job at that point.
Believing a communicating system is required for high efficiency is likely wrong. High performance feedback control technologies located in the outdoor unit like state-space could reduce the response time from feedback only control. I would focus on implementing advanced techniques in a black box sense from the technicians viewpoint. I would keep the wiring and HMI as simple as possible.
It sounds like an Automotive CAN system.
Trying to understand communicating systems by simply discussing the concepts is almost as fruitless as trying to verbally describe basic electrical to a newbie. It really needs more basic slides with illustrations to start visualizing concepts like comm poll response techniques to gather data. It needs definition of what a protocol is with some simple examples. Eg the controller requests current outdoor unit status. A preconfigured group of bytes from the outside unit is sent back. Generally the group of bytes is called a packet and the packet has address and error checking bytes around it. The packet of bytes may have all the on off information and may have all the analog data like rpm, pressures, temperatures from the outside unit. If the controller wants to ramp up the compressor rpm’s it can send a direct command to change to 75% or perhaps 3100 rpm’s. In a similar manner the controller reads and writes data to the indoor unit. Most of the above is communication protocol or standards for this equipment. In industrial environments a protocol analyzer is used to monitor the comm link and decode the data into realtime readable text. Knowing what the pulse streams look like and how to decode them using an scope is not the primary direction or concern. Communication as a problem is normally alerted as a trouble code. The protocol analyzer for industrial can easily be a pc program or tablet app with a low cost hardware interface. Much like an automotive obd2 scanner. An obd2 scanner has a communication protocol and can read and write digital and analog data to the car’s computers. In large part the hvac communicating systems work much like automotive systems. However hvac systems have not standardized their protocols in any way and the typical window into the system is the hvac controller. A different issue is the hvac communication buss hardware. There are electrical comm busses which are robust and largely uneffected by surges and ground voltage shifts. In industrial the busses often are optically isolated from one device to another. Cheaper implementations are ground referenced and have more issues. These are typically built as semiconductor differential drivers which accommodate +\- 12v ground swings and surges but that is it. In those cases it is really better to ensure the communication grounds of connected devices are well connected and the comm line is short. In the end residential comm systems are in their infancy. Primarily to keep costs down and secondarily because the hvac manufacturers are often contracting out the control system design. In ten years we will look at this generation of residential hvac comm systems like we look at dial up modems from 1999 for the internet. The inverters and their robustness will also become much improved. Again look at automotive. Toyota has had inverter controlled AC compressors since 2004 in their Prius with the water cooled inverter in the engine compartment. Reliability and control on those has been exceptional and a pc based application called Techstream can monitor and diagnose anything in the car.
Absolutely agree. My background is Avionics (computers) in Aviation (Military and Civil). Using Standards or Protocols to standardize the communication would allow technicians to easily diagnose problems. But if each manufacturer has their own "language", that creates brand loyalty and only allows parts from those manufacturers to fix their units. Now you remove the simplicity of the older systems with components like capacitors, relays, compressors, etc... from being used across all manufacturers (with some variables), to now manufacturers controlling the prices and availability and more money by the consumers being spent. Brand Specialized technicians as well. Glad HVAC is moving into this territory but unless there is standardization for the design of this communication architecture, going to cause a lot of problems in the future.
Networking. Building automation
Solid comment, thx for sharing
In socal we have transducers on our ultra low nox systems that fail almost everytime but these are on non communicating systems. I would like to understand more about how they operate on a non communicating system. BTW. THEY ARE AWFUL.
How do communicating systems work? They don't!