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[rosinante]

Hi , are there any vfd gurus on the forum please, would like to know if the chineses vfds require a momentary action switch for start stop reverse etc or a latching action , from the drawings and pidgin ingrish instructions Ican find on the Web it isn't clear ,
Cheers

[ZebraDriver]

Tends to be momentary for start and may be NC or momentary for stop. Forward/reverse is normally latching.

[diffwhine]

If I had the foggiest what a VFD was, I might be able to help. Out of pure interest, is there any chance you can enlighten me as to its purpose in life?

[Alan Drover]

Yes, I was wondering too. It doesn't sound like anything Land Rover.

[Wittsend]

I too have/had not got a clue 

Until I Gooooooooooooooooooooooooooooooooooooooooooogled it.

From 

Variable Frequency Drive
From Wikipedia, the free encyclopedia


A variable-frequency drive (VFD) or adjustable-frequency drive (AFD), variable-voltage/variable-frequency (VVVF) drive, variable speed drive (VSD), AC drive, micro drive or inverter drive is a type of motor drive used in electro-mechanical drive systems to control AC motor speed and torque by varying motor input frequency and voltage.

VFDs are used in applications ranging from small appliances to large compressors. About 25% of the world's electrical energy is consumed by electric motors in industrial applications. Systems using VFDs can be more efficient than those using throttling control of fluid flow, such as in systems with pumps and damper control for fans. However, the global market penetration for all applications of VFDs is relatively small.

Over the last four decades, power electronics technology has reduced VFD cost and size and has improved performance through advances in semiconductor switching devices, drive topologies, simulation and control techniques, and control hardware and software.

VFDs are made in a number of different low- and medium-voltage AC-AC and DC-AC topologies.

And so we can allow it as it's a bit of kit you might have/need in your workshops/garages.



Everyday is a school day 

[diffwhine]

The mist has cleared... a bit...

Its the acronym I didn't recognise. I recall training discussions at LR talking about Variable Speed Drives - make s abit more sense now.

Still can't help though! 

[Alan Drover]

Got it. Thanks. I thoroughly it was something to do with computers about which I know absolutely nothing.

[paulv]

The ones I’ve played with have been momentary, to be fair the instructions they come with were ok everything is fully programmable and all the controls on the panel can be wired from a connection block to additional remote switches/pots if required. I used one to control a geared drive on a sawmill head, it works well, you can do so much with them. However they don’t make tea so I still need a Margaret.

[Gingertom]

Generally if you want external (remote)  start & stop pushbuttons then they would be connected as  "3 wire control" with a "normally open" start contact & a "normally closed" stop contact (both momentary) alternatively "2 wires" only requires a "normally open" start signal ie an on/off switch.
Most VSD can also just be controlled in a "local"mode from the keypad (assuming it has one) on the front which should have run/ stop keys

[Herald1360]

FWIW as a retired electronics engineer, my first thought was Vacuum Fluorescent Display, but then the "start, stop, reverse" bit got a bit confusing. 

TLAs can be a minefield......

[riley1ton]

When I use my vfd the next door neighbours broadband drops out.

[Mowersman]

Most can be set up to work with either. A lot have a relay built in that can be used to make a momentary switch into a latching one. I have several VFDs here, using both types of switch.
Andrew

[rosinante]

Hi , thank you chaps , running a woodturning lathe on one of these is an absolute pleasure, along side the infinitely variable speed within the parameters of the drive and motor , controlled ramp up and down ,reversing , no snatching of the drive , looks like Iwill be buying momentary nc and no switches ,
Thanks

[Mowersman]

Hi , thank you chaps , running a woodturning lathe on one of these is an absolute pleasure, along side the infinitely variable speed within the parameters of the drive and motor , controlled ramp up and down ,reversing , no snatching of the drive.
Thanks

They really are the best thing since sliced bread. In my workshop the lathe, mill and bandsaw are all on one. I need to order one for my new compressor as well...
Andrew

[Craig T]

When I use my vfd the next door neighbours broadband drops out.

I haven't seen a problem with our internet connection but we used to have mains wired smoke alarms in the house with a signal link wire between them all, if one alarm goes off it triggers the rest.

My big 3-phase inverter used to upset them though and if the inverter was running for a few minutes without driving a motor all the alarms would sound scaring the hell out my missus in the house normally with a cat sitting on her who would depart the room at a rate of knots...!

I never did find a way to stop it so after looking at the smoke alarms and realising they were a few days away from the expiry date anyway, I tucked the mains wiring into the floor space and fitted independent battery alarms.
I can only assume the inverter was building up some kind of interference in the electric cables?

Craig.