How picky are they in Washington about DIY HVAC? I looked up the relevant code for Idaho and for doing an install on your own residence you don't need a "certificate of competency" but may need to have the install pass a mechanical inspection. (But many HVAC shop techs will insist that ALL such work must be done by a certified technician.)
There are a couple of companies that make DIY mini split heat pumps but their special refrigerant line sets only come in 16 and 25 foot lengths. I need maybe five feet between where I want to put the inside and outside units. For the other makes and models they have all the refrigerant contained within the outside unit and the refrigerant lines use flared ends and threaded fittings. Assemble the system, pull a vacuum on the service port. Close the service valve and disconnect the vacuum pump. Remove the caps off the refrigerant valves and fully open them with a hex key (usually comes with the system) then reinstall the valve caps. Wait around 5 minites to ensure the refrigerant has distributed through the pipes and inside unit and you're finished, aside from setting it up on WiFi and installing the app on your phone, if it has such features. The DIY kits don't need a vacuum pump because the lines are either precharged or vacuumed and they have valves installed on their ends which open as they're screwed onto the other components. NEC code requires a disconnect near the outside unit, placed not more than 6 feet above ground level. Curiously, there's no minimum height above ground level for the disconnect. Rather odd how the NEC code can be so lax and vague on some things but very exacting on others. I happen to have a very good Gast rotary vane vacuum pump that can pull 29 inches of mercury. Just need to come up with the right fitting to put on the end of the hose. I've used it on some vehicle air conditioners, take the car to an AC shop to have the r134a pulled out, bring it home, do what parts need replaced, pull the vacuum myself then back to the AC shop to have it refilled because jumpering wires to the compressor clutch is a bit of a pain to make it draw in from the little cans. $25 to suck the refrigerant out, $25 to put it back in plus whatever for additional refrigerant if needed. I can get a 15K BTU mini split heat pump for well under $1K, shouldn't have to pay some guy another few hundred just to bring out a vacuum pump for a couple of hours then open two valves. The heat pump currently in use for the part of the house served by ductwork was installed over a decade ago and all the company used was a vacuum pump to evacuate the lines. After a couple of hours the tech took the pump off and opened the refrigerant valves. It had a 10 year parts warranty and about a week less than 10 years later the compressor quit. Installing the new compressor was what required the refrigerant recovery system and weighing how much new r410a was put back in. Got nicked $1000 for that for labor and new refrigerant when they should have only charged for the labor and any additional refrigerant that may have been required above what was pulled out. Automotive AC shops will at least credit the value of extracted refrigerant because if they don't put the same stuff back in they'll use it on another job. On Wednesday, July 28, 2021, 6:28:32 PM MDT, Ralph Stirling <ralph.stirl...@wallawalla.edu> wrote: I just got my inspection report by email. The inspector couldn't even remember that it was a mill, and called it a "lathe". He references RCW 19.28 and WAC 296-46B-903. I think my best option is to use this as an excuse to buy a phase converter. It will be UL approved, and I'll connect it to the 220 circuit. It should serve as the "load" as far as the inspector is concerned. I don't want to start lying about my machinery and intentions. A phase converter for testing and repairing 3ph machines is legitimate enough. I'll either tarp my CNC mill in place as Chris suggested, or move it temporarily ($250 for forklift rental twice). The mill is a 1998 French Realmeca C2, with absolutely no labels of any sort on it. Good electrical diagram, but that carries no weight. Thanks for all the advice, everybody. I'll update when I finally pass. I need another visit after I finish installing my ductless heat pump anyway. _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
