Arkansas HVACR NewsMagazine March 2021

S tate, National, Chapter News Tech News

4. EEV Issues : Troubleshooting EEV issues can be very complicated. First, you need to understand where to find the information on how to check them out. Refer to the manufacturer’s published documents for the ratings of each type of EEV coil. Make sure you bring your needle leads, or you’ll break the plug. If the motor ohms out fine, you should check the voltage coming out of the board (typically 12 VDC) and verify that the board is outputting the voltage. As the valve is driving, you’ll see the voltage pulsing, so keep that in mind. If you don’t see the pulsing voltage when the valve should be driving, consider looking at the board. Numerous EEV donut magnets can allow you to operate the valve body by hand (https://weatherallreps.com/shop/ols/ categories/specialized-tools). *NOTE: The board and the valve have no way of knowing if they are out of sequence, so if you move the valve, you need to return it to a spot that the board will know where it is at startup. I suggest running it all the way closed then cycling the power to the machine. If this is not done, compressor failure can and will occur. ** Along with the EEV donut, there is also a handheld EEV driver that fits mo st manufacturers’ EEV plugs. The driver allows you to operate the EEV by hand. (https://youtu.be/xUVV80BcU1M emai l eevmatetech@gmail.com for more info) EEV issues can show up in a starved coil (typical) or a flooded coil. Knowing how

to measure the superheat effectively will help you determine what you’re dealing with. 5. Incoming Power Issues : With all of the electronics in the outdoor unit, mini- splits’ incoming power is less forgiving than their standard equipment counterparts. They are sensitive to voltage outside their specs in addition to surges. Check and see if the manufacturer has a recommended surge suppressor. Corrections to incoming power issues and surge protection are a must. Circuit boards do not like these items, and they will not last if left uncorrected. 6. Condensate Pump Wiring : Please follow the manufacturer’s recommended wiring for the auxiliary contacts to shut down the unit in an overflow situation. Most will break the communication wire, which in most instances is fine, but some indoor units have designated terminals and a plug for condensate overflow that should be used instead. If you wire to auxiliary terminals, ensure that you change the appropriate settings in the controls so the unit will operate correctly. 7. Use Appropriate Connectors : Using wire nuts for communication lines is not the best practice for joining communication wiring together. Butt splices, bell connectors, terminal blocks, and soldered connections are better methods. The use of wire nuts is a communication problem waiting to happen, and I would not recommend