Gene,

If you think you could fix it I'd be more than willing to send the old drive to 
you to work on it.  I am certainly not a CET, but there isn't any obvious 
failures from something blowing up or overheating, and the caps show no visible 
swelling or leaking.

The drive had been acting up for the past couple months.  When the machine 
would be first powered on (throwing disconnect) the drive would not "turn on" 
right away "Power" LED on the front of the drive would not light up, even 
though the drive had power on all 3 phases.  If the machine was left turned on 
for an extended period of time (a half hour or maybe more) eventually the drive 
would power up and work correctly.  This drive has no display other than a row 
of 5 LEDs for fault and power indication.  None of the alarm indicators have 
ever have shown anything.  Last week it stopped working completely.  We are of 
the opinion the problem probably likes in the low voltage board and won't be 
easily found. 

Todd Zuercher
P. Graham Dunn Inc.
630 Henry Street 
Dalton, Ohio 44618
Phone:  (330)828-2105ext. 2031

-----Original Message-----
From: gene heskett <ghesk...@shentel.net> 
Sent: Tuesday, April 26, 2022 2:33 PM
To: Enhanced Machine Controller (EMC) <emc-users@lists.sourceforge.net>
Subject: Re: [Emc-users] Hight Frequency VFD

[EXTERNAL EMAIL] Be sure links are safe.

On Tuesday, 26 April 2022 11:38:47 EDT Todd Zuercher wrote:
> Anyone know a good place to purchase a high frequency VFD?  We had the 
> drive in one of our CNCs die.  The old drive was a HSD DS15000.  The 
> spindle is an 18kw 24000rpm 4pole HSD router motor.

A 2 pole motor should run 24k revs on a 400 hz drive. 30k on 500 hz.
A 4 pole then should run 12k on 400hz, and 30k on 1000hz.  Since motors are 
made in pole counts of a power of two, a 4 pole should run at 24k at 800hz.

> The old drive is
> rated for 1-1000hz and that seems to be the problem, all of the off 
> the shelf drives I can find are limited to output frequencies less 
> than 500hz which would limit our spindles top speed to only 15000rmp.
> Our machine builder quoted us for a Yaskawa V1000 drive with 1000hz 
> firmware (model# VU4A0038FAA-134) that they do have in stock but they 
> are marking up their price to more than double the normal list price 
> for that drive.  Every other place I've checked with so far are 
> quoting us months long lead times for that drive.

Putting on my Certified lectronics Technician hat, how about fixing that drive?

Unless the motor has developed shorted turns, the inductance of all 3 windings 
s/b within 5% of each other, mucking up the impedance of a winding, which might 
blow some output bugs, the most common failure is the big filter caps which 
most chinese drive makers claim should be changed at 5 year intervals due to 
ESR growth. That of course leads to heating and is self feeding until the cap 
vents or even explodes. They are what stores the relatively slow 60 hz 
rectified power, making it available at the high frequencies these motors need.

So, whats wrong with that drive? Open it up and take a look, Todd. Any sign of 
a bulged top/bottom or even a whitish leakage condemns them to replacement with 
fresh ones, probably from the capacitors orginal maker.
The original vendor of the drive may have them too but his will likely be as 
old as the ones you're looking at, so go to the capacitor maker, they'll be 
fresher.

If you have an ESR meter, those should certainly read, with a 4 terminal 
measurement, well under half an ohm which I'd call instant grounds for 
replacement. .1 ohm or lower would be even better. 2 lead measurements will 
swamp out at much higher readings because of the lead ohmage. A 4 lead 
measurement sends the exitation signal down one set if leads, and reads the 
result from another set of leads, both leads hitting a single connector per 
src/load, so they only read the capacitor, not the test leads.

Such an ESR meter should be in your kit Todd, but lock it up when not in use, 
they aren't $175 cheap like the two lead version made by a guy in KC-MO I've 
used for nearly 4 decades now in lower powered electronics.

Its literally as useful as sliced bread or bottled beer on the test bench.
[...]
> ask nicely and then maybe they might sell you a drive with the 
> "special" HF firmware.

You've already got one, fix it. For 20% of a new ones cost. Or less...

> Todd Zuercher
> P. Graham Dunn 
> Inc.<https://nam04.safelinks.protection.outlook.com/?url=http%3A%2F%2F
> www.pgrahamdunn.com%2Findex.php&amp;data=05%7C01%7Ctoddz%40pgrahamdunn
> .com%7Cd60b8c8acfae46f7227408da27b35a43%7C5758544c573f47cebee96c3e0806
> fb43%7C0%7C0%7C637865948772332793%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4w
> LjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C
> &amp;sdata=w5Y%2BJICZjBhcDKy49wPwqC5fydGaygI2lIp9i5jwrX8%3D&amp;reserv
> ed=0>
> 630 Henry Street
> Dalton, Ohio 44618
> Phone:  (330)828-2105ext. 2031
>
>
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Cheers, Gene Heskett.
--
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author, 1940)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis





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