Previous in Forum: Actuator Display Showing Torque Trip CL Alarm and Torque Trip OP Alarm   Next in Forum: Lvdt Connector Looseness?
Close
Close
Close
4 comments
Anonymous Poster #1

Radial Vibration

04/20/2020 12:50 PM

What will be the vibration panel reading if radial vibration X and Y output Gap voltage set to -9 VDC or -11 VDC instead of -10VDC output gap voltage. For example; if radial vibration gap voltage were set to -10 VDC and during compressor running. active alert alarm appear. Will it be clear the alarm when it will adjust to -11 VDC output gap voltage from -10VDC?

Reply
Interested in this discussion?
You can "subscribe" to this discussion to be notified of new comments.
Click on the Subscribe menu at the top of the page.
Guru
Engineering Fields - Electrical Engineering - Been there, done that. Engineering Fields - Control Engineering - New Member

Join Date: Dec 2008
Location: Long Island NY
Posts: 14885
Good Answers: 916
#1

Re: Radial Vibration

04/20/2020 2:07 PM

Alarm levels are set on a machine by people that know the machine's operational limits. You haven't even told us what is this machine. The manufacturer and model identification are useful to know. Volts Direct Current (VDC) are not a unit associated with mechanical vibration. In fact by definition a DC voltage should not vary at all. Gaps are typically measured in units of linear dimension; millimetres, inches, microns and sometimes when measuring the gap of a chasm in miles.

Now the voltage across the magnetic gap between stator and rotor cores in an electric motor will be the voltage arcing across the bearings. This arcing accelerates the bearings wearing out due to pitting and should be kept as low as possible. That is if this is what you are measuring to cause an alarm.

If the manual doesn't say you can change this limit or you do not have a manual to look this up don't touch the limit setting.

__________________
"Don't disturb my circles." translation of Archimedes last words
Reply
Guru
United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain. Kettle's on.
Posts: 29966
Good Answers: 809
#2

Re: Radial Vibration

04/20/2020 2:43 PM

It is impossible to answer this question without the operation and maintenance manual for the equipment in question, the details of which have been withheld from the forum.

__________________
"Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
Reply
Guru

Join Date: Jul 2016
Posts: 1000
Good Answers: 67
#3

Re: Radial Vibration

04/21/2020 1:11 AM

You need to adjust the alarm limits when you change the excitation voltage. In the range you are looking at, it will be close to a linear relationship. Your old scale was 50% displacement at 5 volts, now 50% will be 4.5 volts or 5.5 volts, so you need to adjust the alarm according to the same proportion.

Reply Score 1 for Off Topic
Guru
Engineering Fields - Mechanical Engineering - New Member Hobbies - CNC - New Member

Join Date: Aug 2006
Location: Western Australia
Posts: 751
Good Answers: 58
#4

Re: Radial Vibration

04/21/2020 4:01 AM

If your are referring to Bently Nevada proximeters then the answer is no difference at all. The probes are usually set at -10V, but will read between -2 and -18V.

They register relative movement of the shaft to the bearing housing and as long as you are within the linear range of the probe it will make no difference if the voltage is set anywhere in the range that you mention.

Axial probes are a completely different matter.

__________________
If you can't explain it simply, you don't understand it well enough. (A.E.)
Reply
Reply to Forum Thread 4 comments
Interested in this discussion?
You can "subscribe" to this discussion to be notified of new comments.
Click on the Subscribe menu at the top of the page.
Copy to Clipboard

Users who posted comments:

PWSlack (1); redfred (1); rwilliams (1); The Prof (1)

Previous in Forum: Actuator Display Showing Torque Trip CL Alarm and Torque Trip OP Alarm   Next in Forum: Lvdt Connector Looseness?

Advertisement