SL 10 Low voltage alarm

[PBMW]

Here's a question for ya...
I have a 2004 LS10 and a Servo 300 barfeed. This is run off of a 20hp Phase Perfect. I have a building that in the past was a duplex and therefore has two main power boxs. The lathe will low power alarm sometimes when one of my 7 1/2 hp compressors kicks. Thing is though...the compresor is on the other power main. They are seperate.
Is this because the control is running on the manufactured leg? I had been told that with a phase perfect that there is no phase delay.
Thoughts?

[Geof]

You have two main power boxes in the building but it is almost certain they are both connected to the same transformer. All you are doing is pulling the transformer voltage down when the compressor kicks in. You don't say but I am guessing your compressor is runningon single phase; that would be a very large starting surge.

One way that you can reduce the starting surge on the compressor is fit a centrifugal or fluid clutch on the motor pulley; this allows the motor to come up to about 70% of top speed very quickly. Actually it doesn't reduce the surge it just makes it a lot shorter so it does not exceed the low voltage parameter timeout on the Haas. Contact an outfit that supplies pulleys and belt they should be able to help.

An alternative to take the surge away completely is put an electric clutch on the motor pulley, wire this to the pressure switch and leave the motor running constantly. You only get a big surge the first time you fire it up in the morning.

[PBMW]

Yea. They are both single phase 7 1/2 hp
The one that kicks the Haas is an Husky 25 cfm 80 gal that runs at 3400 rpm
I also have an Eaton 32CFM 220 gal that runs at 1700 motor rpm. 800 pump rpm. It does not trip the Haas. Both have unloaders of course.

[Geof]

My diagnosis is that the 3400 rpm motor takes longer to come up to speed so as I mentioned the parameter timeout is exceeded. Changing to a 1700 rpm motor with a different pulley size might do the trick but you probably want to avoid buying new motors.

As I mentioned earlier look for one of the centirfugal or fluid coupling pulleys. I used them on a big bandsaw that was always popping breakers on start up; they greatly reduce the length of the starting surge. You could do a test; take the belt of and see if just starting the motor running free still gives the low voltage alarm. If it does you are a bit stuck but at least you haven't spent any money to find this out. If it doesn't there is no guarantee the centrifugal pulley will work but it is a good bet.

Another thing you can try but I do not recommend it is to increase the timeout; the alarm tells you what parameter it is I think and the value is probably in milliseconds.

Found some links;

http://www.blm-cm.com/prod6.htm

http://www.wichitaclutch.com/SoftStartApplication.asp

http://www.blm-cm.com/productover.htm

[PBMW]

Kewl. I'll look into it.
Thanks