[squirrel_41]

Hi mactec54 not trying to steal this topic but I noticed in another post you said you have repaired many VFD drive's I have a blown Huayang 3kw unit and I need to know the value of the back to back Zener diode's on the IGBT gate I think there 18 volt can you confirm this also can I replace them with 16 volt which I have plenty off.
Cheer's

[mactec54]

Hi mactec54 not trying to steal this topic but I noticed in another post you said you have repaired many VFD drive's I have a blown Huayang 3kw unit and I need to know the value of the back to back Zener diode's on the IGBT gate I think there 18 volt can you confirm this also can I replace them with 16 volt which I have plenty off.
Cheer's

There have been a lot of different changes in what they use, as the fail rate has improved each year, I have not had any to repair for some time, as the parts and the user Parameter set up have got better, as for your Zener diode it needs to match closely to the IGBT 2 volt difference may be ok, but I have always matched the Zener to suit what is in place already,I have used higher voltage but never lower, give it a try, it will either work or give the IGBT a shorter life

It's strange that you only have to replace just the Zener

What are the Zener #, I may be able to compare some I have used

[squirrel_41]

Oh no its not just the zener all the igbt's are shot as well also 1 blown track ,I only had enough parts on hand to replace half the output so I replaced Q17,Q19,Q21 hoping I could continue to use the unit in one direction (I don't need both) while waiting for the part's ,however it does not work even if I select forward or revers I can only assume the switching is on different igbt's but then I could be wrong and have more problems.
I do have a full set of IRFP 460 Mosfets could I replace the igbt with these.
Cheer's thanks for the reply.

[mactec54]

Oh no its not just the zener all the igbt's are shot as well also 1 blown track ,I only had enough parts on hand to replace half the output so I replaced Q17,Q19,Q21 hoping I could continue to use the unit in one direction (I don't need both) while waiting for the part's ,however it does not work even if I select forward or revers I can only assume the switching is on different igbt's but then I could be wrong and have more problems.
I do have a full set of IRFP 460 Mosfets could I replace the igbt with these.
Cheer's thanks for the reply.

The Zener's I used where IN4148 , the 460 20a 500v should work , if the board is too bad, it's cheaper to get another VFD, what happened to blow yours so bad

[squirrel_41]

Im.not sure it is a water cooled spindle I often run it at a slow rpm 1100-1200 rpm drilling with a 3mm bit into 316 stainless and she just went bang it has been running fine for about 2 years
The vfd is rated at 13 amps I have checked all my settings and my max current was set 11 amps it has never shut down on over current limit before.
When its running that slow it pull's about 10.2 amps which has always been a little confusing for me I thought at a low rpm the amp draw would have been a lot less.
Since the blow up I have check the resistance of my motor 0.8 ohms between all three phases no leakage to earth.
So you think it's okay to try the Mosfets I would really like to get up and running again its real pain in tha!.
Cheers

[mactec54]

Im.not sure it is a water cooled spindle I often run it at a slow rpm 1100-1200 rpm drilling with a 3mm bit into 316 stainless and she just went bang it has been running fine for about 2 years
The vfd is rated at 13 amps I have checked all my settings and my max current was set 11 amps it has never shut down on over current limit before.
When its running that slow it pull's about 10.2 amps which has always been a little confusing for me I thought at a low rpm the amp draw would have been a lot less.
Since the blow up I have check the resistance of my motor 0.8 ohms between all three phases no leakage to earth.
So you think it's okay to try the Mosfets I would really like to get up and running again its real pain in tha!.
Cheers

That is way to slow to run these spindles, they have a minimum speed of 6,000 RPM and that is normally of not much use at that speed, you must of changed the torque / voltage control parameters, or the spindle would not of drilled the holes at those speeds, I would say you got lucky to run that long, with using incorrect Parameter settings for your motor

The amp draw at low speeds would be running at more than the spindle rated amps, that is why they fail, if you need low speed fit a regular AC motor to do the slow work

The voltage may may be to low with the 460's, but you could try them, this is a good replacement FGA25N120ANTD 1200V 50A NPT

[john-100]

check the zenner diode number !!

the 1N4148 ( like the 1N914 ) is a Silicon Small Signal Fast Switching Diode

John

[mactec54]

check the zenner diode number !!

the 1N4148 ( like the 1N914 ) is a Silicon Small Signal Fast Switching Diode

John

That's the correct number used in the Huangang VFD, for the Zener diode there are others that they used also

[squirrel_41]

Okay I just checked my notes when I did the last parameter change below is a copy of my notes as i wrote them at the time
------------------------------------------------------------------------------------------
I have increased pd009 from 15 to 19
this has improved the low speed torque a lot.
I increased pd145 from 2 to 4 dont seem to make as much differnce as
increasing pd009
I had to increase pd014 to a higher value to make a slower start up
otherwise with the increase in pd145 the unit will trip.

pd052 is for the fan or pump
pd014 accel time 12
pd015 decel time 6


RPM Current Amps All readings are with no load

100 3.8 increasing pd010 from 6.5 volts to 8 volts ups the amps to 5.5 Amps
200 8.4 It also trips the vfd at 200 rpm
300 10.2
500 10.5
1000 11.0
2000 5.9
3000 3.4
5000 2.6
10000 2.3
15000 2.3
20000 2.0
24000 1.8
-----------------------------------------------------------------------------------
Strange that it run so long without a problem
The curent IGBT's are b1g125 fga25n120 antd

[squirrel_41]

Does any body have a 3KW chinease spindle that could measure the winding resistance between the 3 input wires
Cheers

[mactec54]

Does any body have a 3KW chinease spindle that could measure the winding resistance between the 3 input wires
Cheers

They normally are in the range of 1.4 to 1.6 some also have been lower / higher but not by much

[squirrel_41]

Hi Mactec as you know my vfd blew I replaced all the blown parts and tracks checked everything connected it up and it blew again
So again I replaced all the parts and rechecked again and again could find nothing wrong with the VFD
To try and stop it blowing up again I connected 2 X 150 watts security lights in series with the 250 Volt input power
Reset and rechecked all VFD param
Run it up with nothing on the output except a multimeter everthing performed as it should I could ramp the output volts up and down forward and reverse
Monitoring the globes for brightness there was virtually nothing just a slight dimness if there was a switching short in the Mosfets the globes would have lit up but nothing so move on to next step

Okay so I connected it up to my spindle motor (Keeping the globes in series just to sure)
issue s6000 M3 from Mach3 spindle runs for a couple of turns sounds normal mach3 resets because VFD faults with UL ( to be expected huge voltage drop from globes about 3 amps max input)
issue same command except M4 try reverse same as above Hmm all seems good
okay remove globes issue same command BANG !
I am confident the VFD was fixed properly
Remove spindle remove covers check for water leakage in spindle nothing dry as a wooden god
This spindle has never been overheated never been stalled
The only thing is the resistance between windings is 0.8 ohms nothing down to earth infact it could be as low as 0.6 connecting lead together reads between 0.1 and 0.2
I would really like someone with a 3KW water cooled spindle to do quick check of there resistance.

[mactec54]

Hi Mactec as you know my vfd blew I replaced all the blown parts and tracks checked everything connected it up and it blew again
So again I replaced all the parts and rechecked again and again could find nothing wrong with the VFD
To try and stop it blowing up again I connected 2 X 150 watts security lights in series with the 250 Volt input power
Reset and rechecked all VFD param
Run it up with nothing on the output except a multimeter everthing performed as it should I could ramp the output volts up and down forward and reverse
Monitoring the globes for brightness there was virtually nothing just a slight dimness if there was a switching short in the Mosfets the globes would have lit up but nothing so move on to next step

Okay so I connected it up to my spindle motor (Keeping the globes in series just to sure)
issue s6000 M3 from Mach3 spindle runs for a couple of turns sounds normal mach3 resets because VFD faults with UL ( to be expected huge voltage drop from globes about 3 amps max input)
issue same command except M4 try reverse same as above Hmm all seems good
okay remove globes issue same command BANG !
I am confident the VFD was fixed properly
Remove spindle remove covers check for water leakage in spindle nothing dry as a wooden god
This spindle has never been overheated never been stalled
The only thing is the resistance between windings is 0.8 ohms nothing down to earth infact it could be as low as 0.6 connecting lead together reads between 0.1 and 0.2
I would really like someone with a 3KW water cooled spindle to do quick check of there resistance.

Because you ran the spindle so slow it was over heating, it would not show on the outside because of the water jacket, having the wrong Parameters set, can damage these spindles and VFD in about 5 seconds or less, which many have found out, it never ends good when you have a 400Hz 24,000 RPM spindle trying to run and work at 1100 RPM , running these spindles anything below 100Hz ( 6,000 RPM ) it will be cooking inside, ( over Heating for sure )

You can not use a normal multimeter on the VFD output, as it can damage the IGBT, and will not give you any valid readings, only a scope or a very expensive Fluke that are designed for measuring a VFD output,can be used

Check the wiring in the spindle plugs to see that none of the wires can touch, causing a short, this has happened before, but it does sound like the spindle is cooked, and the insulation is breaking down once you apply the power to it