What is jogging function of the inverter ?
What is jogging function of the inverter ?
(OP)
Hi guys,
I saw many inverter products today equipped with Jogging function. As far as I know, it's the function that can let the operator to do manual operation with the motor. But what is really the purpose of that in real application ? I mean, if the motor can be rotated automatically, why the inverter still provide the manual operation (jogging) ?
Thanks.
terwelu
I saw many inverter products today equipped with Jogging function. As far as I know, it's the function that can let the operator to do manual operation with the motor. But what is really the purpose of that in real application ? I mean, if the motor can be rotated automatically, why the inverter still provide the manual operation (jogging) ?
Thanks.
terwelu





RE: What is jogging function of the inverter ?
There is another operating mode called inching. For very large machines that did not lend themselves to jogging, inching was sometimes used. This was the great grand father of invertors. A DC source would be applied to the motor windings in turn be a series of contactors. The contactors may be controlled by a sequencer or manually by a wheel or crank that operated limit switches that controlled the DC contactors.
Consider a large ball mill (possibly over 20 feet in diameter) that must have an access hatch aligned properly when it is to be removed for internal service of the mill as one possible example.
This system could provide a crude stepped square wave that would cause the motor to rotate slowly and under control.
Although jogging with a VFD may be more analogous to inching than to jogging, inching systems were quite rare and the term jogging is more readily recognized.
Bill
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"Why not the best?"
Jimmy Carter
RE: What is jogging function of the inverter ?
I heard about that set of contactors being controlled by a cam plus limit switches. Thought it was a funny story. But, you say it did exist IRL?! Do you have any links to such a beast. Would be very interesting to see one.
Gunnar Englund
www.gke.org
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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: What is jogging function of the inverter ?
check for correct rotation at startup
some machines require jog movement to check components at certain spots, by slowly jogging to that spot.
Rotate the motor to bring the machine to a certain position
RE: What is jogging function of the inverter ?
As waross mentioned a common reason is to get hatches or doors into position.
Keith Cress
kcress - http://www.flaminsystems.com
RE: What is jogging function of the inverter ?
"If I had eight hours to chop down a tree, I'd spend six sharpening my axe." -- Abraham Lincoln
For the best use of Eng-Tips, please click here -> FAQ731-376: Eng-Tips.com Forum Policies
RE: What is jogging function of the inverter ?
Thank you all for your information. Very appreciate it !
So in principle, please correct me if I'm wrong, jog function will be (mainly) used for maintenance activities and non-automatic process. I guess it won't be any special purposes to use this function for main activities of the system itself.
Can I take those statements as "rough" conclusion for jogging function ?
terwelu
RE: What is jogging function of the inverter ?
RE: What is jogging function of the inverter ?
When you and I were young, I had some old textbooks. One scheme rotated the motor in step with the control wheel. I think that if the operator overshot, he could turn the wheel backwards and run the motor backwards, but I can't say for sure about that function.
My library is spread from my place in Honduras across my cabin and my mother's place in British Columbia to our new place 1600 kilometers east in Alberta, and I am in a construction camp 700 kilometers north of the Alberta place. I'll probably be doing the loop in the next couple of months. If I come across the reference I'll try to get it to you.
Yours
Bill
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: What is jogging function of the inverter ?
Most VFD's will require different commands to activate a RUN and speed/frequency setpoint (not always) but a JOG is the combination of the two. More often than not it is a low speed/frequency (about 5Hz) at default and can be programmed to go FWD or REV.
RE: What is jogging function of the inverter ?
Gunnar;
They're not a myth. The scheme works very well for positioning a ball mill powered by a brush type sychronous motor. The contactors make a pretty light show. Attached is a short cut from the video. I'd have psoted a longer better quality clip on a sharing site but we're not allowed to access those sites here... so I spent well over half the morning cutting the video until it would upload directly instead.
RE: What is jogging function of the inverter ?
Keith Cress
kcress - http://www.flaminsystems.com
RE: What is jogging function of the inverter ?
Gunnar,
Think of it as a very crude form of electro-mechanical cycloconverter.
"If I had eight hours to chop down a tree, I'd spend six sharpening my axe." -- Abraham Lincoln
For the best use of Eng-Tips, please click here -> FAQ731-376: Eng-Tips.com Forum Policies
RE: What is jogging function of the inverter ?
Can't see the vid in windows media or apple player. Is there another software for that video ?
RE: What is jogging function of the inverter ?
"If I had eight hours to chop down a tree, I'd spend six sharpening my axe." -- Abraham Lincoln
For the best use of Eng-Tips, please click here -> FAQ731-376: Eng-Tips.com Forum Policies
RE: What is jogging function of the inverter ?
Keith Cress
kcress - http://www.flaminsystems.com
RE: What is jogging function of the inverter ?
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: What is jogging function of the inverter ?
RE: What is jogging function of the inverter ?