How To Repair Zone Board On Hvac System

Air Conditioner Circuit Board Troubleshooting Question - Hello, my name is Calvin and I am an HVAC Technician that graduated from a community college 2 years ago and I am however learning and know I accept much more to acquire before I think of myself as an expert. I have been running into a lot of circuit boards in air conditioners and heat pumps and I merely want to know what is the best manner to troubleshoot and air conditioner circuit board? It seems like a lot of electronics and they never covered electronics too much in school.

I do understand basic electrical circuits and how circuits work in the air conditioners and heat pumps I work on but more and more than systems are getting electronic circuit boards and I would like to know the best style to troubleshoot these air conditioner excursion boards so I can make the repair.Thanks for your assistance and I take learned a lot from your website. I look forward to your reply!

Air Conditioner Circuit Board Troubleshooting

Air Conditioner Excursion Board Troubleshooting Answer

Hullo Calvin, and thank you for the slap-up comments most our website. We sincerely appreciate information technology! Information technology is good that you accept the attitude that you have nigh continuously learning new things. You could work in this industry for many years and still not know everything. So keep it up and continue sharpening your skills, and it volition comport y'all far. I take seen so many technicians who think they know everything. They end upward being humiliated and frustrated because of their over-confidence.

Equally far every bit troubleshooting circuit boards for air conditioners, I apply a straightforward dominion to make things easy. We practise not have an electronics lab or electronic parts (aside from carrying a few resistors for discharging capacitors) that we acquit on the service van. Neither do nosotros have any of this at the shop. Using the process of elimination, you lot tin can come to the decision that the board is bad.

I know you mentioned air conditioners and rut pumps, merely this too applies to gas furnaces. Many gas furnaces use circuit boards to control the ignition procedure and other parts of the gas furnace. Circuit boards also control ECM blowers. And so yous tin employ this information to many other components and equipment types within HVAC.

Air Conditioner Circuit Lath Troubleshooting Guide

E'er check to make sure everything in the system is working properly or not malfunctioning. Outset with the basics and piece of work your way to the problem. Of course, depending on the upshot will depend on where and what you look at with the organisation. That is truthful for air conditioner troubleshooting, rut pump troubleshooting, or gas furnace troubleshooting.
A circuit lath in the most common organization works off of input and output. First, make sure y'all have power to the board. In some cases, this will be line voltage, and in other cases, the lath will get its power from the control transformer. Either way, check to make sure you have the proper input voltage to the board.
Next, you want to bank check the output, and this is a little more involved than the previous stride. Many air conditioner circuit boards rely on a prophylactic check earlier information technology sends an output point or voltage to the device it is controlling. At that place is usually a check through all the safety circuits earlier the lath will allow an output signal. The nigh mutual of these are limit switches and force per unit area switches. If any of those switches are open, and so the board will not allow an output signal to the device information technology is controlling. Some boards you jump out the safety circuit, and if the unit starts working correctly, then you know there is a trouble in the safety circuit that needs to be addressed. Annotation: Whenever you detect a trouble in a safety circuit, never assume it is a bad switch. Always look for an issue that caused the switch to open. That is very important, especially for furnaces. This step involves a clear understanding of an air conditioner sequence of operation and air conditioner components. Of course, if it is a estrus pump or furnace, you should understand the sequence of operation and components of those systems also. And always retrieve, while some equipment has similarities, not every single piece of equipment is the same and will vary for components and sequence of operation, peculiarly gas furnaces.
If you lot do not find any issues, after all that, then you can kill the power and carefully remove the lath from its mounting pins or bracket and wait at the dorsum of the board. Many times I have seen something burned out on the circuit lath by observing the back of the circuit lath. In that case, you need a new circuit board to solve the problem. Depending on the complexity and connections to the lath, accept a photograph of information technology before you disconnect anything. That will give you reference when reinstalling all the terminations. In some cases, manufacturers make the board connections/terminations idiot-proof by using one-mode Molex connectors/plugs.
The piffling blackness cubes you lot run across on the air conditioner circuit board are typical relays that will energize a fan motor such as a blower motor or a condenser fan motor. If the fan fails to energize and there is no output from the air conditioner excursion board, take a screwdriver and using the handle of the screwdriver tap the picayune blackness cubes on the board (on a telephone call for heating or cooling of course). Sometimes the relay contacts inside the petty black cube volition stick, and with a little tap, they release and shut (or open if the fan motor will not stop when not calling for operation). In that case, y'all demand to replace the air conditioner excursion board. Otherwise, the trouble will continue.

Dip Switches

Dip Switch Settings

Finally, some circuit boards have dip switch settings that may need manual settings. The rule with this is if something has changed or if someone has changed the dip switch settings inadvertently? To get the right settings on the dip switches yous will need the manufacturer's installation guide and the specific technical information for the equipment being controlled. Some example of boosted information can be:

Tonnage
CFM'south
Dehumidification Sequence Options
ECM Variable Speed Motor Options
Staging Options
Additional features such as a humidifier or electronic air cleaner

In some cases, the rocker switches on the dip switch board are tiny and difficult to come across. You will either need a magnifying drinking glass or utilise your smartphone to take a picture show of the dip switch lath so yous can zoom in on the dip switch board and verify the settings are right or align with the manufacturers settings based on the manual.

Air Conditioner Circuit Lath Troubleshooting Conclusion

Information technology is bones input and output. You lot must have the proper input to get the proper output. I have a customer where I found a bad board with burn marks on the back. The function of the board that burned out controlled the blower motor. It was a very hot summer and I did non take that board on the truck and it was a very good possibility they would accept to wait a few days for me to order and get the board delivered. I simply bypassed the board for the blower and fabricated the blower run all the time.

While the blower ran all the fourth dimension everything else was controlled normally through the board. I could have hooked up a relay and made it work there but I asked the customer what they wanted and gave them their options. They told me it would be okay to run the fan all the time merely they wanted the system fixed with a new board. So if y'all observe yourself in a similar predicament Calvin, yous can always bypass the circuit board to make things work just remember to never bypass whatsoever safeties in the system. Good Luck!!

PS…..you can apply our search feature hither to find other troubleshooting and sequence of operation information for different types of HVAC equipment. We are currently building a cross-index compendium for all of our articles to arrive easier to find various related articles.

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