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stylishzaki
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Join Date: Jun 2012
Posts: 6

Single Phase Electric Motor Speed Controller

07/04/2012 4:36 AM

Hello guys i have one industrial exhaust fan which is single phase 220V,50HZ and 4 amps i want to control the speed of exhaust same as we are controlling the speed of normal ceiling fan with dimmer/regulator.i checked in the market to buy some regulator but i did not found 4amps its huge current right for the regulator.then i checked the price of motor drive/inverter and its too expensive to buy now some body told me to install potential meter i am not familiar with this thing so guys help me out and tell me can i used potential meter on this motor to control speed if yes then tell me the connection if motor have starting capacitor or running capacitor or both then how to connect the cables to the potential meter plz explain me the connection in easy words.
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PWSlack
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#1

Re: Single phase electric motor speed controler

07/04/2012 5:39 AM

Restrict the outlet of the fan in some way, maybe by fitting an exhaust duct damper and making it partially closed.

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tcmtech
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#2

Re: Single Phase Electric Motor Speed Controller

07/04/2012 5:46 PM

Replace it with a multi speed fan motor designed for such purposes.
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Ron
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#3

Re: Single Phase Electric Motor Speed Controller

07/05/2012 12:04 AM

It's a guess, but I think what somebody told you to use is a POTENTIOMETER, not a "potential meter". I think that they're more commonly used with DC motors, but I could be wrong. This is basically a variable resistor. There are also variable-voltage transformers (autotransformers) which MIGHT work - the common name is Variac. Your 50Hz motor may be designed to run at one speed; there are Variable Frequency Drives which could possibly control speed by changing the frequency of the input power. However, your comments suggest that the cost of one of these, or the cost of a Variac, will be a big problem.

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rakesh_semwal
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India - Member - New Member Engineering Fields - Electromechanical Engineering - New Member

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#4

Re: Single Phase Electric Motor Speed Controller

07/05/2012 12:46 AM

You can buy a 10 to 20amps triac from market and make a simple circuit like one of these.

You just need to find the adequate values of R AND C for the triac you select for your application.
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durtieduck
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#5

Re: Single Phase Electric Motor Speed Controller

07/05/2012 1:10 AM

i'm not an electritrician. replacing the motor with an appropriate dc motor should allow you to control the speed with a rheostat
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rakesh_semwal
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#6
In reply to #5

Re: Single Phase Electric Motor Speed Controller

07/05/2012 1:17 AM

Replacing AC with DC is almost as expensive as putting a VFD on system, which is beyond the financial reach of OP.
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on7ami
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#7

Re: Single Phase Electric Motor Speed Controller

07/05/2012 3:20 AM

Hello,

Important question: do you know the type of motor used? Mostly the only way to control speed of those motors is by varying the frequentie of the power. This is quite expensive and if posible it would be less expensive by replacing the potor by a DC one and regulating the speed with a PWM and a HexFET.

Greets

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jerrys
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#8

Re: Single Phase Electric Motor Speed Controller

07/05/2012 4:10 AM

You aren't going to vary the speed of an AC motor with a dimmer or a potentiometer. The speed of the AC motor is determined by the frequency, the 50 Hz.
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Bazzer Englander
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#9

Re: Single Phase Electric Motor Speed Controller

07/05/2012 4:40 AM

Find an old commercial cooker hood and take the speed controller out of it fit to your fan and if it's OK copy it.

Bazzer.

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JIMRAT
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#10

Re: Single Phase Electric Motor Speed Controller

07/05/2012 6:55 AM

Jaycar Electronics in Australia make a 10 amp motor speed controller kit for AC motors at moderate cost.

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stylishzaki
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Join Date: Jun 2012
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#11
In reply to #10

Re: Single Phase Electric Motor Speed Controller

07/05/2012 9:53 AM

thanks buddy
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Users who posted comments:

Bazzer Englander (1); durtieduck (1); jerrys (1); JIMRAT (1); on7ami (1); PWSlack (1); rakesh_semwal (2); Ron (1); stylishzaki (1); tcmtech (1)

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