Skip to main content

Tagged With "pseudo"

Topic

Pseudo tach for variable input speeds

Nosreme ·
I'm trying to use the pseudo tach feature when collecting data for an intermediate shaft in the gearbox using CSI2140. The motor constantly changes its speeds while running (ramps up, slows down and stop to make one cycle) controlled by a VFD. Will the pseudo tach feature work on this application? I put in the correct input/output ratio or tooth count but the detected running speed of the intermediate shaft in the software doesn't seem to be correct. Will the pseudo tach work on variable...
Reply

Re: Pseudo tach for variable input speeds

Walt Strong ·
I can't say specific to 2140, but in the olden days: Do you have a tachometer on the motor shaft? If yes, then for machine setup choose Enter Speed only Once = No, and Check/select on Fixed Tach Location The Motor shaft speed Reference and each measurement point Reference (ratio accordingly) are part of the Measurement Point setup. The intermediate measurement points on gearbox would then have the speed ratio to the actual motor speed. It would be wise to make all measurements on machine at...
Reply

Re: Pseudo tach for variable input speeds

Walt Strong ·
"Using "fixed tach location", will the speed of the intermediate shaft be changed proportionally based on the ratio added to the reference RPM? As I'm using a tachometer, will the software auto calculate the speed of the intermediate shaft based on the ratio?" Yes. For example: Motor Reference speed is 1800 and Fan Reference speed is 900 rpm (0.5 ratio). Say actual motor speed from Tach is 1600 rpm (overwrites 1800), then fan speed would be scaled to 800 rpm when measurement is made. No...
Reply

Re: Pseudo tach for variable input speeds

Walt Strong ·
My previous comments are probably good for route measurements. Here is a description of the fabulous Pseudo Tach: https://reliabilitymobile.com/...hometer_Analyze.html From this list: https://reliabilitymobile.com/csi2140/index.html Walt
Reply

Re: Pseudo tach for variable input speeds

Nosreme ·
Yes and I did read the formula "(Incoming tachometer frequency) X (( tach frequency X the number of teeth on the tached shaft)/number of teeth on the pseudo shaft)" Does anyone know what this tach frequency is?
Reply

Re: Pseudo tach for variable input speeds

Nosreme ·
Thanks a lot for the clarification on the fixed tach location feature.
Reply

Re: Pseudo tach for variable input speeds

Nosreme ·
Thanks all. Yes, I use a tachometer to measure the motor speed at the motor outboard cooling fan (this is the only place to measure the motor speed). Even if the machine RPM is put in as 1720 RPM (for example), this is never the true turning speed and the motor changes its speeds while collecting data. Using "fixed tach location", will the speed of the intermediate shaft be changed proportionally based on the ratio added to the reference RPM? As I'm using a tachometer, will the software auto...
Reply

Re: Pseudo tach for variable input speeds

Nosreme ·
Either way, the ratio or tooth count used. As the intermediate shaft cannot be directly tached, I attempted to use the pseudo tach option while taching the motor shaft. If the motor has constant running speed then the pseudo tach will work based on the correct given speed ratio or tooth count. What about a motor that is changing its running speeds while collecting data, will the Pseudo tach somehow show the order tracked running speed as the motor shaft is being tached
Reply

Re: Pseudo tach for variable input speeds

John from PA ·
I'm not familiar with what you are asking about but have to ask if you can input the ratio as an actual tooth count as opposed to the ratio? In addition, very often the ratio is not correct as stated and should be verified.
Reply

Re: Pseudo tach for variable input speeds

Nosreme ·
Yup, that is correct. Thanks for your responses
Reply

Re: Pseudo tach for variable input speeds

Walt Strong ·
" F2 Pseudo Tach "Enable Pseudo Tach for time synchronous averaging or order tracking intermediate shafts in gearboxes that cannot be accessed directly. Use the Pseudo Tach to produce the turning speed signal. The analyzer uses the following formula: (Incoming tachometer frequency) X ((tach frequency X the number of teeth on the tached shaft)/number of teeth on the pseudo shaft). Disable Pseudo Tach when you can use the tachometer directly on a shaft. The default is Disabled." I guess CSI...
×
×
×
×