On Sun, 20 Aug 2017 18:09:20 -0400, Gene Heskett <ghesk...@shentel.net>
wrote:
On Sunday 20 August 2017 03:40:56 David Berndt wrote:
I'm having some issues commissioning my HY VFD. 4kw unit driving a 5hp
3450rpm motor at 30hz max frequency (temporary 2 pole motor, 4 pole
motor is in the mail). Works great in "forward", but when it accels in
reverse it trips out and throws an E.OC.N error. Which appears to be
an over current error.
I've flipped 2 leads to the motor, reversing the physical rotation and
it still works great in vfd "forward", proving that the motor and
mechanical aspects work in both directions. But the VFD does not.
Accel times are quite conservative/slow. Problem happens about 1
second into acceleration. No clue.... There don't seem to be any
relevant settings. Problem happens regardless of control method,
modbus or operator panel.
Unrelated, but wow, at low speeds this VFD seems to throw off a ton of
interference. The symptom I've noticed is that my usb mouse connected
to the PC in the control cabinet that also houses the VFD basically
gives up on life if the motor is running below 15hz. USB dongle modbus
was fairly impacted as well until I grounded the cable shield to the
pc case.
I had noise worse than the coaches megaphone, so I put a 20 amp rated
Corcom brick wall in the AC line feed. Works a treat.
Any particular series you picked? Does it really matter? I assume some
filtering, even one of the corcom filters rated as general purpose would
be better in front of the vfd than nothing at all?
Just to make this slighlty more on topic. Is there a config somewhere
for maximum spindle RPM? With the drive configured correctly it won't
overspeed the motor, but it would be nice if the software was aware of
a top end for spindle speed as well.
What are you using for an interface between the pwm (or pdm) gen, I am
assuming the pwmgen is in a mesa interface card?.
It's just a usb to modbus dongle. So the hy_vfd user componenet. I
realize there are ways to solve this in HAL but none of them seem to
enforce the same way softlimits do, or I'm doing something wrong. I'm
looking for something that will throw an error and power off the machine
g-code sets and S command too high, or the manual control screen is used
to set the rpm too high (ideally the interface would just stop increasing
the spindle speed once it hits the max...).
I had been assured by the ebay critter that sold me the 1.5 hp vfd,
hooked to a 1 horse 3 phase motor from a 30 yo compressor, that the
analog input filtering was good and that I could feed the analog input
(0 <-> 5 volt range, it has both 5 volt and 10 volt inputs) directly
from the pwm generator, but I was unable to get good smooth control.
My motor is a 4 pole, and at light load it has been spun north of 7K
rpms. No damage if the internal fans don't throw blades, but because of
motor winding inductance, current draw is well under an amp/phase so
usable torque is an oxymoron, there isn't much. Practical limit for my
setup is about 140hz. From 8hz to 140hz doesn't make me switch drive
belts from 1st gear, no backgear.
I don't plan to run a great range of motor speeds, but getting it up to
90hz to pickup some spindle speed would be nice if the gearing and spindle
will take it. On the low end, if something like 20-30hz would be usable
I'd probably be satisfied, just enough to limit trips ot the back of the
machine to throw gear select levers.
I had a mesa spinx-1 I had taken out of TLM because I was putting in a 40
lb supply and one of Jon's (Pico Systems pwm-servo amplifiers, great
device BTW), so I pulled it out and hooked it up. Works Perfect. With
a bit of tuning in the vfd, I can even do rigid tapping on the old grey
Sheldon up to around 200-250 spindle rpms. Above that and the overshoot
at reversal exceeds a full turn of the chuck.
The spinx-1 needs separate fwd and rev signals, not a problem to hack
that in your .hal file, but yell if you need some snippets of hal code,
I might be able to help.
Thanks,
Dave
Cheers, Gene Heskett
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