Motor soft Starter. How does it work?
Hi. My house runs on a generator. I have a problem with the ACs when they kick in. each AC (and there are three of them, one on each phase) pulls 18 Amps as when the compressor kicks in. Is there a way to make it have a ’soft start’? Here’s an excerpt from an article I read on the web:
"One method is to use the same wire used to feed power to the input of small HP AC drives and create an air core reactor by winding the feed wire into a coil, with a diameter of the width of a hand, about 75 turns and tie wrap the coils. This is done in each input phase. In many installations, these �handmade coils� will provide sufficient inductance to slow the current and limit over voltage shutdowns"
So can I put this 75 turns winding at the input of each AC so that i can reduce the start up current to its operating current of 8 Amps?
Your advise would be very much appreciated
it may work. there are commercially made soft start units that you can install that may work better. you can also wire the units so that they can only start one at a time and never together.
3 Comments »
Lee D said :
December 22, 2008 at 12:57 pm
You could get what they call a hard start kit.It just consist of a large capacitor,and it’s wired across the start relay.It gives the compressor a boost when it starts and get it up to run speed faster.I have no idea about the coil things,sorry.
References :
freakboynv2008 said :
December 22, 2008 at 1:34 pm
it may work. there are commercially made soft start units that you can install that may work better. you can also wire the units so that they can only start one at a time and never together.
References :
Relled Legin said :
December 24, 2008 at 5:49 am
Sorry it will not work. The soft start described does slow down the rate of current rise but only by a few microseconds. This is probably to reduce radio interferance or transients. It will not reduce the load during the start up of your AC compressor motors sufficiently to prevent overload of the generator.
A "soft-start" circuit which effectively works a bit like an automated lighting dimmer switch is what you need, unfortunately I do not know of any suppliers of these that would be suitable for your application.
Update: try http://www.fairford.co.uk/hfe.html
References :
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