compresor motor starting
compresor motor starting
(OP)
i have 25 hp ,440 V motor connected to compressor through v belts. which type of starting will be better --- resistance or magnetic
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RE: compresor motor starting
"...resistance or magnetic" is rather ambiguous.
Not enough to go on--probably the one that makes the least noise in the belts.
RE: compresor motor starting
its a squrriel cage induction motor. by resistance ,i meant putting them in line for some time and then taking out after motor picks up speed. similarly magnetic soft starters are also available which give smooth starting as compared to star delta starter. going for electronic soft start will be costly for this application as existing resstance starter was working fine but is to be replaced by new one because of aging.what exactly i wanted was whether putting mgnetic soft starter in the motor input will be any better?
RE: compresor motor starting
Also if you had a wound-rotor motor with slip rings, then you could insert resistance in series with the rotor circuit for reduction of starting current, but I don't think you have that.
RE: compresor motor starting
I would look into the electronic module type of soft-start. These devices provide the very basic soft start and stop functions only and are used in conjunction with a normal full-voltage magnetic starter. For 25HP at 480V 60Hz worst case pricing is probably $800 (US).
Some manufacturers are:
Schneider Electric - type LH4N
Motortronics - XLC series
Carlo Gavazzi - RES
RE: compresor motor starting
In general, reduced-voltage starting is employed for two reasons—during the starting interval, for reduction of stress on the electrical system, and/or for reduction of mechanical stresses.
I agree with electricpete and JBD on the marginal utility of resistance starting.
There are two arrangements for Y-∆ starting—[basic] open-transition and [more complex] closed-transition types. Realize that to apply Y-∆ starting, the motor terminals must be internally configured to accommodate it.
“Reduced Voltage Starting Of Low Voltage, Three-Phase Squirrel-Cage Induction Motors”
http://www.squared.com/us/products/nema.nsf/DocumentsByCategory?OpenView&Start=1&Count=999&Expand=15.2#15.2
http://www.squared.com/us/products/nema.nsf/DocumentsByCategory/EE6359C1AC2882238525673D006D5AB7
RE: compresor motor starting
thanks for your suggestions, i will consider all the above points before replacing the starter. this motor doesnt have all the 6 winding ends coming , so star/delta starting is ruled out. this is also not a wound rotor type motor.
RE: compresor motor starting
RE: compresor motor starting
RE: compresor motor starting
ANOTHER OPTION IS TO USE ELECTROMAGNATIC SOFT STARTER WHICH IS BIT ECONOMICAL THAN ELECTRONIC SOFT STARTER
RE: compresor motor starting
normally , the compressor is started on no load only but i am ruling out direct on line starting as it will cause drop in the line causing problems to the other loads. i will take into account the suggestions given. thanks again..