New HVAC RTU CHEAPER? install almost destroys Scroll Compressors! How to start 3 phase units
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- Опубликовано: 28 сен 2024
- #3phase #3phasemotor #rtu #hvactraining #hvactraining101 #hvacschool #hvacmaintenance #hvacexperts #hvaccontractor #hvac #diy #howto #hvactechnician #hvactech #hvactroubleshooting #hvactrainingvideos
if they go cheap they pay more later never fails
Careful with that too, if the blower is a VFD the motor will spin the right direction, regardless of phase rotation.
Punch compressor contactor and feel for a cool suction within seconds.
A few weeks ago my eBay find a BK Precision Model 302. Tells rotation from power or you can spinn the motor to find its rotation.
@@HVAC559 yes sir! Good comment... I watched and heard myself give the installer too much credit... they didn't switch anything for the blower.... the vfd fixed that. They simply didn't check, anything.
Great explanation, love the videos you share. An apprentice would learn so much working alongside you.
@@jorgejanicas8289 thx , just trying to share what I can with my son and if others can get some good from it ... awesome!
Since the blower is running on a VFD, it will always have correct rotation as 99.9% of VFDs don't care about incoming power phase rotation. You have to ALWAYS bump the compressors to verify they are correct.
@@mxslick50 correct! Vfd will always put blower into correct rotation after start attempts..I said it wrong.. thx for the correction. As you said main point👉 Always check compressor rotation regardless of blower operation.
I don’t know why installers don’t realize it’s out of phase….
because maybe they have no idea what they are doing is my take so why check that lol
They hire guys straight out of "HVAC License School" and expect them to have a masters in HVAC.
@@grantbrown-t2u important to remember most people do a good job... the one's who don't either aren't being taught, not being supervised or just... don't care. Makes the rest of us look bad....
It takes a lot of knowledge to be a comercial HVAC tech, to the point that it is overwhelming for a new tech. You have to know how the refrigerant cycle works; how air behaves; how water vapor behaves; know the mechanical code; know plumbing; know electrical & the NEC; know controls modbus, backnet, 0-10 V dc, 2-10 V dc, 0-20 mA, or 4-20 mA; VFD's; economizer 's especially in Cali; you may still need to cool the space when it's 50° F outside; some companies you need to do refrigration. It goes on and on.
Each brand has its little differences as well. We avoid some brands like TRANE because there's no tech support and there systems have non conventional controls. With TRANE, you had better have your decade box with you, because on some models RYGW is factory disabled!
Refrigration is a whole beast in itself. The controls are not very complex and your evaporator is in the space so that makes it easier than HVAC, but there's spoiling product on the line. Everything is an emergency. If a walk-in is down at 3AM You have to go. Those contractors will even roll to a store at 3AM for HVAC because the chocolate will melt!