Re: [EVGRAY] help!

Body

Hi  Warren,

The SI prefix m is milli meaning 10^-3. For micro (10^-6) use μ (mu) or u.
SI prefixes: https://wiki2.org/en/Metric_prefix#List_of_SI_prefixes https://wiki2.org/en/Metric_prefix#List_of_SI_prefixes

Regards
Ole
 

---In [email protected], <schoonersolsticemoon@...> wrote :

 My cell phone auto corrects and the mg is supposed  to be not micrograms, but
 MICROFARADS! It kicks, and screams, having a hissy fit, when I deviate from the Samsung vocabulary spelling, and even sneak in the changes after I hit "send."
 I think I might prefer my clumsy typos, and key punch errors, instead.
 I notice others have similar issues with their devices.
 Cheers Warren
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 On Tue., 25 Jun. 2019 at 5:43 a.m., Warren Keillor schoonersolsticemoon@... [EVGRAY]
 <[email protected]> wrote:

   Info
 Welcome to our group!
 Your RV  should not run hot, if experience with my 3 hp 480 volt Chinese WEG 1800 rpm 60hz is any indication. It stays cold.
 I made a very good capacitor switching box, right from the beginning of my experiments with the RV.
 I took a plastic water proof tool box, and mounted all my oil filled 600 volt capacitors In it.
 The hinged lid was drilled to mount toggle switches in two rows, with labels for the mf value of the capacitor each switch controls.
 I found it difficult to get 1 mf oil filled capacitors, but was able to get 2 mg, 3, and 6 values.
 With a bank of these, along with some 20 mg, plus the 140 mg starting cap, which is on a momentary contact switch, only used to start the motor, to get it up to speed.
 Using, for instance, 15 mf as a rough guess for keeping it running after you reach your (1800) rpm (in my 60 hz case) you can start watching your amperage draw, and switch off some low value capacitors, seeing the load drop to as far down as it can run
 In my case, it runs full speed with sealed greased bearings, but with the fan removed, at 400 ma.
 An identical motor with the seals and grease removed that I have runs at 200ma.
 Both are tested with 120 volts 60 hz line voltage.
 Using a Variac, I have run them full speed at 72 volts but no great torque.
 I would not bother destroying the grease and seals, as longevity in a dusty environment, or quiet reliability is nice once you use for a practical use, you may find, after your initual discoveries thrill wears off.
 I don't use the shaft torque so much, though I guess I can, as a shop rotary wire brush, or buffer.
 The best thing is using the capacitor circuit in series, with a primary transformer load.
 One must have a switch, to shunt off the primary until your motor is up to full speed, using the momentary start capacitor.
 Then you open the shunt once you no longer use your start cap. and everything has been settled down with your running caps.
 Of course once your load comes on you will play your switches like a piano, at first, until you learn the happy values that are needed.
 I hope this helps
 Cheers Warren

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 On Tue., 25 Jun. 2019 at 3:27 a.m., info@... [EVGRAY]
 <[email protected]> wrote:

   
 Hi everyone, I'm new to the group and first of all I wanted to thank 
 everyone for their kindness. I have a problem with a rotoverter. The 
 motor is a three-phase 5,5horse, 50 hertz (I am in Italy), 4 windings. 
 690v star connection. 1440rpm per minute (the engine can even go up to 
 60 hertz with 830V and 1730 revolutions is shown on the plate) Now I 
 am testing it with the 220v 50herz rotoverter system, but I saw that 
 it has little force and the rotor (cage) squirrel) warms up a lot 
 ....... how come? ... I bought a variac to bring the voltage to 1/4 (172 
 volts) and I'm waiting for it to arrive, but is that just the problem 
 or else? ...... Thank you so much for helping me out.