What motor capacitor? Calculations?

Hi-tech electronic and computer equipment and Internet. Better use of electricity, help with the work and specifications, equipment selection. Presentations fixtures and plans. Waves and electromagnetic pollution.
luffy46230
I discovered econologic
I discovered econologic
posts: 2
Registration: 24/07/10, 10:49

What motor capacitor? Calculations?




by luffy46230 » 24/07/10, 12:23

Hello

I do not know if these are the right headings for this kind of message and I apologize!

Well here is my concern I have a compressor compressor, 3 KW under a network of 380 star coupling!

good and I want to do it in mono, I heard that it takes a capacitor for startup but which to choose?
and especially where can one find some?

Thank you for answering me !
0 x
User avatar
gegyx
Econologue expert
Econologue expert
posts: 6931
Registration: 21/01/05, 11:59
x 2870




by gegyx » 24/07/10, 14:21

0 x
dedeleco
Econologue expert
Econologue expert
posts: 9211
Registration: 16/01/10, 01:19
x 10




by dedeleco » 24/07/10, 16:29

Bayer solution type ersatz, for not too much power and too strong starting torque, with a motor that may heat up more!
It may not start if no luck with a bit limited engine.

possible supplier
http://www.condensateurs.net
Conrad
http://www.conrad.fr/condensateurs_de_m ... 122945_FAS
http://www.electrome.fr/produits/compos ... arrage.htm
but I have the impression that these capacitors have a current too weak!
Basic advice (risk of explosion)
http://www.volta-electricite.info/artic ... r&pg=11016
https://www.econologie.com/forums/moteur-asy ... t3613.html

http://www.google.fr/webhp?client=firef ... 895908a673
0 x
luffy46230
I discovered econologic
I discovered econologic
posts: 2
Registration: 24/07/10, 10:49




by luffy46230 » 24/07/10, 16:57

We look forward to seeing you!

But these rather capacitor capacitance which I do not know which one to take!

my motor has an intensity of 11,5 when it is coupled in triangle and a useful power of 3 000 W = 3 KW

please
0 x
dedeleco
Econologue expert
Econologue expert
posts: 9211
Registration: 16/01/10, 01:19
x 10




by dedeleco » 24/07/10, 17:26

Ideally, the motor choke should be measured when stopped and running to calculate the capacitor that will phase out from 90 or 120 ° to 50hz (oscilloscope).
This can work if the engine is oversized, otherwise with 30% less it will cause startup problem and warm up !!
Pay attention to the direction of rotation that must be visible.
0 x
User avatar
chatelot16
Econologue expert
Econologue expert
posts: 6960
Registration: 11/11/07, 17:33
Location: Angouleme
x 264




by chatelot16 » 24/07/10, 19:37

no need to measure the self: it varies completely with the speed of the rotor ...

the optimum capacitor for having the best starting torque (at 0 speed) and the best performance at normal speed is not all the same

the best solution is to test

capacitor too small: not enough torque of demarage

capacitor too big: the engine growls and heats up at normal speed

certain motor are not even usable with a single capacitor: it is necessary a big capacitor at the demarage, and disconnected a part has normal vitess

do not forget: the capacitors simply add themselves by putting them in parralele: it is therefore easy to test with a pile of small capacitor, to see if it works better with one more or less

this method works well with the very old engine that is very little heating and had the margin of safety: with the recent motor limit in three-phase, it is good only for short-term use in mono
0 x
User avatar
gegyx
Econologue expert
Econologue expert
posts: 6931
Registration: 21/01/05, 11:59
x 2870




by gegyx » 24/07/10, 20:06

luffy46230 wrote:We look forward to seeing you!

But these rather capacitor capacitance which I do not know which one to take!

my motor has an intensity of 11,5 when it is coupled in triangle and a useful power of 3 000 W = 3 KW
please

In my link:
http://www.aupoele.fr/index.php?option= ... Itemid=123

3KW ==> 4CV
==> Delta assembly and 200 or 320 uF capacitor, depending on the direction of rotation desired.

You have your approach, what do you need more?
After you finish with the use and advice of Chatelot16

Of course, switching to mono is a bastard solution with less efficiency.
0 x
User avatar
Forhorse
Econologue expert
Econologue expert
posts: 2485
Registration: 27/10/09, 08:19
Location: Perche Ornais
x 359




by Forhorse » 25/07/10, 09:18

Since a compressor starts directly in charge, I doubt that the solution is anyway functional.
It will certainly add a pressure switch with built-in decompressor, as are almost all compressors with mono motor.
0 x
boubka
Grand Econologue
Grand Econologue
posts: 950
Registration: 10/08/07, 17:22
x 2




by boubka » 25/07/10, 12:05

Hello
3 kw is a lot, and you're better off having mini 45 amps on the meter
Image

I am not sure that at rated pressure (8 bars in general) your engine is powerful enough, may not be achievable by this technique.

the single-drive dimmer either because it stopped at 2.5 kw and hello the price

the driver remains (or dynamic converter) that gives you all the power but consumes almost double but can absorb the boot intensity.
if you have available another engine 3 kw voila schema.
you can add as many engines as you want, the whole increases its power provided you have enough on the mono meter.
I made one and it works very well.
Image
1 x
Other
Pantone engine Researcher
Pantone engine Researcher
posts: 3787
Registration: 17/03/05, 02:35
x 12

Re: Which motor capacitor? Calculations?




by Other » 25/07/10, 17:08

Hello
luffy46230 wrote:Hello

I do not know if these are the right headings for this kind of message and I apologize!

Well here is my concern I have a compressor compressor, 3 KW under a network of 380 star coupling!

good and I want to do it in mono, I heard that it takes a capacitor for startup but which to choose?
and especially where can one find some?

Thank you for answering me !



Do not confuse a single-phase motor with a starter coil (smaller file) and a three-phase motor that you want to operate in single-phase
First the three-phase motor when it will walk in single phase, must agree to a power loss of 40%

The editing is quite simple
An electrolytic capacitor designed for the AC 150 250 micropfarad that is connected in series on a phase, just for the start, then it must be isolated (there are relays specially designed for this on many compressor air conditioning)
to change rotation just change a lead of the phase condesator

For your tests, a simple push button to turn on the capacitor at startup, then you loose it.

the capacity of the capacitor depends mainly on the starting torque of the motor, whether it leaves in load or empty

Single-phase motors that operate with a small capacitor permanently connected (run capacitor) have a winding specially designed for this purpose.

Andre
Last edited by Other the 25 / 07 / 10, 22: 30, 1 edited once.
0 x

 


  • Similar topics
    Replies
    views
    Last message

Back to "Electricity, electronics and computers: Hi-tech, Internet, DIY, lighting, materials, and new"

Who is online ?

Users browsing this forum : No registered users and 107 guests