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View Full Version : VFD Has defantly blown up now!



charlieuk
22-08-2017, 02:04 PM
HELP! I think I have had it 3 year maybe with varying amounts of use and a few intermittent problems along the way however it has just given the big white puff of smoke!

question is what to replace it with? another Chinese one I got from chai or something else?

need to act fast though as I have work waiting.

magicniner
22-08-2017, 03:30 PM
Just buy one from China again, if you want guaranteed up-time buy two and rotate them, replace them as they blow.
I use Siemens and still have spares on the shelf ;-)

- Nick

charlieuk
22-08-2017, 04:58 PM
HELP! I think I have had it 3 year maybe with varying amounts of use and a few intermittent problems along the way however it has just given the big white puff of smoke!

question is what to replace it with? another Chinese one I got from chai or something else?

need to act fast though as I have work waiting.

I have ordered on from cnc4u as the can get itvto me this week just need to find out why it blew, I noticed a flash come from the plug on the spindle so I assume it was something that end, I found a scorch mark to prove this on the plug

I'll have to try order a spare when I get some cash back in.

routercnc
22-08-2017, 05:12 PM
I have ordered on from cnc4u as the can get itvto me this week just need to find out why it blew, I noticed a flash come from the plug on the spindle so I assume it was something that end, I found a scorch mark to prove this on the plug

I'll have to try order a spare when I get some cash back in.

Mine did exactly the same as after many years of use the constant movement on the cable and plug caused the pins to have a bit of play in them. It arced and the vfd cut out. I didn't realise what had happened and carried on for a few days. Then it arced again and the vfd was toast this time. It was an expensive Moeller drive at about 350? and had a quality feel to it but they all go the same way if power is interrupted to the motor momentarily.
I bought a Chinese one which blew the moment I switched it on, so swapped it for another and that was has been fine. I direct soldered the cables (remove end cap) added a strain relief collar and added an earth cable inside the housing. Strongly recommend this sort of mod otherwise you will blow another one if the connector can move around when the machine is cutting.

If you go for another plug then make sure it is a good fit on the pins and the cable has strain relief and cannot move around near the plug end.

charlieuk
22-08-2017, 05:39 PM
soldering it sounds like a good move I will be sure to do that, did you take the 4 pins out and then modify it so the wires went through the top? along with the earth?

Clive S
22-08-2017, 08:15 PM
soldering it sounds like a good move I will be sure to do that, did you take the 4 pins out and then modify it so the wires went through the top? along with the earth?

It is a common mistake not to securely fix the cable to the VFD plate so that there is no strain on the plug, If you take the cap off be careful as the water inlet and outlet might need to be resealed.

routercnc
22-08-2017, 10:51 PM
Have a look here:

http://www.mycncuk.com/threads/7545-VFD-error/page3

Boyan Silyavski
23-08-2017, 03:52 PM
Could it be that it shorted inside? Measure the coil's resistance. It may be water damaged? Then open, clean , dry and thats it

Clive S
23-08-2017, 04:24 PM
Could it be that it shorted inside? Measure the coil's resistance. It may be water damaged? Then open, clean , dry and thats it

I very much doubt it

Boyan Silyavski
23-08-2017, 05:05 PM
I very much doubt it

You may doubt it as much as you like, but once when i was cleaning my spindle by mistake i used compressed air and that's what happened. So i had to open, dry , close again and it worked. i have seen on forums some people that have a leak and when closed the leak, then all was fine. It takes a minute to measure if its shorted to body.

charlieuk
25-08-2017, 06:26 PM
New spindle and vfd arrived from cnc4u and I have replaced them wire for wire. Are there any tests I can do to make sure all is ok before I do any damage? We think the fault was at the plug so I have soldered the wires this time as suggested. I did not set up my original and I'm terable at reading (dislexia) and I'm just trying to establish if there is anything that I need to program on it. The new one has a little dial for sped I asume however the old one was set up for the speed to adjust on Mach 3? I'm terafied of turning it on and it going bang again!

Clive S
25-08-2017, 08:42 PM
Ok First with the spindle wires (three of them) if you have them connected incorrectly it will run in reverse so when you first start it check to make sure it is spinning the correct way. If it is wrong just change over any two of the wires.
You can do this at the VFD end on the U:V:W terminals.

You will have to ask cnc4you if the parameters have been set up in the VFD. The Chinese ones quite often need to be set. There is a list of them on the forums some where.

Neale
25-08-2017, 11:01 PM
Back when I bought my VFD and spindle from CNC4YOU, they came already configured for front-panel control of speed and needed tweaking for Mach3 speed control. But that was over 5 years ago. Good news is that the same VFD and spindle are still working and in regular use!

charlieuk
25-08-2017, 11:35 PM
I have been trying to look at the manual but most of it is going straight over my head and im not sure what much of it means, they did mention it should be set up but looking at the instructions and what you say maybe its not? what are the things that I should be checking? im assuming some how I can power it up to look and not blow anything up?

charlieuk
27-08-2017, 09:10 AM
can anyone help, what are the main settings I should be checking on the Huanyang vfd before starting the spindle up?

routercnc
27-08-2017, 09:15 AM
Try here:
http://www.mycncuk.com/threads/5814-The-2-2Kw-Chinese-Spindles-Info-Setup-and-Advice-More

Doddy
27-08-2017, 10:02 AM
soldering it sounds like a good move I will be sure to do that, did you take the 4 pins out and then modify it so the wires went through the top? along with the earth?

I genuinely interested and a little confused... how was the original connector made-off last time, if not soldered?

Okay, the connector pictured is a little different to the usual chinese jobs that have solder bucket terminals.

Where I'm coming from is that soldering isn't regarded as a particularly vibration-tolerant electrical termination method (crimping is widely regarded as superior). Unless the OP had, perhaps, screw-terminals?

Clive S
27-08-2017, 11:10 AM
I genuinely interested and a little confused... how was the original connector made-off last time, if not soldered?

Okay, the connector pictured is a little different to the usual chinese jobs that have solder bucket terminals.

Where I'm coming from is that soldering isn't regarded as a particularly vibration-tolerant electrical termination method (crimping is widely regarded as superior). Unless the OP had, perhaps, screw-terminals?
Doddy If you are looking at the green connector then I think that is just a 3D printed cover to cover the hole up in the top of the spindle. The original plug and socket have been discarded and the cy cable soldered directly on to the spindle wires.

My personal opinion is that I would not do this but keep the original plug and socket BUT securely fix the cable to the spindle plate so as there can be no movement in the plug and socket as this is a source of problems with vfd's letting magic smoke out.

Doddy
27-08-2017, 11:20 AM
Doddy If you are looking at the green connector then I think that is just a 3D printed cover to cover the hole up in the top of the spindle. The original plug and socket have been discarded and the cy cable soldered directly on to the spindle wires.

My personal opinion is that I would not do this but keep the original plug and socket BUT securely fix the cable to the spindle plate so as there can be no movement in the plug and socket as this is a source of problems with vfd's letting magic smoke out.

I was looking at the picture on page 1, but now having seen your reply I've noticed the second image. Not keen - I'd be concerned that such thin-walled printed structure certainly will be porous and provide little to no mechanical relief. I'd agree with Clive's suggestion - get some saddle clips (or similar rigid mount) on the plate and tie-wrap the cable-form to these. It works on fast-jets, should be fine on a milling machine.

magicniner
27-08-2017, 01:22 PM
New spindle and vfd arrived from cnc4u and I have replaced them wire for wire. Are there any tests I can do to make sure all is ok before I do any damage?

If you have metered across the phase wires in pairs and all 3 sets of windings read similarly and you've metered the resistance to earth too and that reads open circuit then your motor is fine and you shouldn't be able to damage a VFD with it.

- Nick

A_Camera
27-08-2017, 01:42 PM
soldering it sounds like a good move I will be sure to do that, did you take the 4 pins out and then modify it so the wires went through the top? along with the earth?

I don't think that soldering directly is a good idea at all. It makes removal complicated, cleaning servicing difficult. Also you still need strain relief, even if you solder the wires. There is really no advantage, only disadvantage compared to using aviation plugs.

charlieuk
27-08-2017, 07:37 PM
I was looking at the picture on page 1, but now having seen your reply I've noticed the second image. Not keen - I'd be concerned that such thin-walled printed structure certainly will be porous and provide little to no mechanical relief. I'd agree with Clive's suggestion - get some saddle clips (or similar rigid mount) on the plate and tie-wrap the cable-form to these. It works on fast-jets, should be fine on a milling machine.


I am far less concerned about the printed part failing now than the plug they come with. I can apply all the force I want with my hands to the spare I printed and could not any signs of movement or cracking between the print layers, its got a 3mm wall that tapers up and solid infill, the layers are extremely well fused together, I have been so impressed with the strength of parts that come of my prusa! The only thing that may destroy it would be a few hefty blows from a hammer. Now I have the printer I will also re do the cable support that was bolted to the main frame above the old plug. The wire will never move in the blue tubing ( it was a sod to get on) and that is permanently fixed to the printed part so should never move and have taken any chance of stress going onto the motor wires inside.

The plug witch now is obvious was the failure point on the system and considering the plug was still locked down when I removed it after it failing shows it is a weak point and when you look at them the fitment and would assume the contact of the pins to be fairly poor and im not going to risk it again, In the past I have noticed the locking collar has managed to loosen its self over time although that wasn't the case when it blew and was the first thing I checked. remove the fault and remove the problem.

magicniner
28-08-2017, 12:06 AM
3mm wall that tapers up and solid infill, the layers are extremely well fused together, I have been so impressed with the strength of parts that come of my prusa! .

What material?

charlieuk
28-08-2017, 01:10 AM
Just pla I have done stacks of stuf with it now and have been so impressed. I have stronger filaments but not yet found the limits of pla easpesialy when it comes to small things like this I would be very sure the cable would give way before the printed part ever gets close. If you have that sort of load going on the cable you have something very wrong!

magicniner
28-08-2017, 01:20 AM
That'll be fun if the motor gets warm, within spec, just fairly warm for a motor ;-)

Check out the glass transition temperature of PLA, that's why it's not suitable for stuff on your car dash ;-)

charlieuk
28-08-2017, 07:24 AM
That'll be fun if the motor gets warm, within spec, just fairly warm for a motor ;-)

Check out the glass transition temperature of PLA, that's why it's not suitable for stuff on your car dash ;-)

After 3 year I have never had the spindle get even remotely warm even when I once found the water pump to have stoped, it hardly rises above ambient temperature and im quite often doing 8h tool paths however it no suprise as it only cutting polystyrene so not exactly working hard. Should it ever become a problem I'll just print it from something else. I have actually thought of a new idea to improve it and to work with the cable support so I will probably swap this one over but I will still just use pla it's more than adequate for the job on this machine

charlieuk
28-08-2017, 10:08 PM
To keep all thouse happy I put a extra clamp on the cable tower and then I re made the cable support now that I have the printer and swapped it over quickly this eve.

I have allso switched on and all seams ok other than the control not working from Mach3. I have a signal going to the motion controller but the vfd doesn't respond so I'm guessing there it's in the programming which I will look for tomorow.

charlieuk
29-08-2017, 12:32 PM
Ok all up and running now and I have control from Mach 3 ( I set 001 to no.1) however if I want to bump the spindle speed up with the up arrow nothing happens. I'm assuming 002 needs to be allso changed to the same ie no.1 set by external terminals?

routercnc
29-08-2017, 01:40 PM
Ok all up and running now and I have control from Mach 3 ( I set 001 to no.1) however if I want to bump the spindle speed up with the up arrow nothing happens. I'm assuming 002 needs to be allso changed to the same ie no.1 set by external terminals?

It's been a long time since I set mine. Away from machine so will need to check later.

On the strain relief grommet - can the cable move about independent of the spindle? If it can it really needs to give a gentle flexible support to the cable so it does not flex in the same place. Instead the cable should curve gradually to spread the stress out. Otherwise with repeated movement the cable itself may break where it exits the support bracket. You can either design a new grommet (mk3 !) with some gradual flex element as you move away from the spindle, or buy one of these:

22691

Top right end clamps either side of the spindle end plate
Bottom left end is the spring element providing graduated support

But if it exits the spindle and goes into an energy chain (which is also supported at the spindle end) then I think you are OK as you are as this will act as the spring flex element.

charlieuk
29-08-2017, 02:12 PM
The cable runs up and through the inside of my z axis And every axis has cable chain. The cable comeing from the spindle does not ever move other than vibrations, the blue tube is silicone so that should take the point load of the joint and dampen vibrations. I would have thought if I were to get a failure now it would be in the cable in the chain that is constantly moving,how long are cables expected to last? I agree if the wire was just going straight up to were ever and no chain it would need more but I'm not sure why anyone would do that.

charlieuk
30-08-2017, 12:07 AM
I tried all the settings in program 002 and still don't seam to have control over the speed via Mach 3 only on and off.

Is there maybe something else as well that needs to be switched at the same time?

Ger21
30-08-2017, 03:18 AM
There's a jumper on the VFD that you may need to change? See page 10 in your manual.

Clive S
30-08-2017, 09:10 AM
I tried all the settings in program 002 and still don't seam to have control over the speed via Mach 3 only on and off.

Is there maybe something else as well that needs to be switched at the same time?From the manual:-

PD001: Command source. Set to 0. 0 means you're controlling the spindle via the front panel controls. 1 means you're using controls that you've wired up to the screw terminals. 2 means you're going to control it using RS-485.

PD002: Speed control source. Set to 1. 0 means you're controlling the speed through the up and down front panel buttons. 1 means you're going to control the speed with either the knob on the front or an external potentiometer. 2 means RS-485.

When PD002 is set to 1, there is also a jumper next to the screw terminals that you have to set. If the jumper is on the right pair, the control is the front panel knob. If the jumper is on the left pair, the control is via an external potentiometer connected to the screw terminals. Make sure the jumper is on the right-side pair.

charlieuk
30-08-2017, 02:03 PM
Cheers many thanks that did the trick sory if it was odvios in the manual I just really struggle with reading pages of text. Think we are all sorted now and have already got 10h on the new spindle and vfd.

I opened the old vfd up and there is a green resistor that looks like it was what got toasted. Is it likely this is the only thing that went or would have other stuff gone to, just wondering if it's worth geting looked at and repaired?

Many thanks for all the help

Boyan Silyavski
30-08-2017, 03:45 PM
The VFD does not have so many things to check as you may think. Here is a link (http://www.motioncontroltips.com/troubleshooting-vfds-101-with-no-power-checks/) to basic testing, most of all test the rectifier. Is it worth it, who knows. A Siemens drive that had a blown part and cost me 20euros to repair was worth it, as it costs new 700euro. If problem was the rectifier it alone costs 200-300. At the same time a chinese drive costs 100 euro. At the other hand the Siemens had maximum frequency of 1000hz i believe and a cheap chinese drive has 400hz max frequency, that also may matter.