View Full Version : blowing electrontics
markct 06-22-2007, 04:57 PM anybody have any thoughts on why i would be replacing:
2- z axis amps, z axis motor and a vector drive all within the last 2 years?
is this normal for a 1997 vf4?
shouldn't the z axis fuse protect the amp boards????
070622-2016 EST USA
markct:
Not normal.
All the servos and the spindle use the same high voltage power supply, about 325 V, in the vector spindle drive for both the spindle and servo system. I do not believe there were any particular quality problems for machines of that age.
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HuFlungDung 06-22-2007, 10:03 PM Possibly the transformer taps (in the Haas) were not correctly set and your power company is providing power a bit higher voltage than would be optimum? The inverter provides the power for the servos. Maybe it is a case of the weakest link in the chain will fail eventually from the stress of too high voltage.
I think you probably have incoming voltage problems. Has anyone ever told you about changing the transformer taps at the bottom of the control cabinet to match your incoming line voltage and keep the DC bus between 320 and 340 volts.
The Haas tech who services my machines has stressed that going outside these limits is risky and can damage things. He said running too high can lead to overheat alarms and running too low can prematurely fry the elctronics.
You can see the DC bus voltage on the Diagnostics screen if you page down once (I think). Check it at different times of the day; your incoming voltage may fluctuate depending on the time of day.
serviceman 06-23-2007, 06:03 AM the early haas amps rev f where really weak and so where the earlier vector drives if the vector drive has a bar under the screw terminals where you have to put a screwdriver through the slot to get to the screws then it was garbage and bound to fail the older vector drives blew when you smoked an amp the newer ones alarm out when they sense a short.
markct 06-23-2007, 01:57 PM thanks for the ideas. the transformer taps where checked and i just checked them again. shouldn't the z axis fuse protection fault out before the amp blows. i'm concerned that i shouldn't put another amp in if that isn't working.
Al_The_Man 06-23-2007, 02:31 PM I am not familiar with this exact machine, but If you have the taps set for the incoming service value and it is right on the edge, it may pay to up the tap one to the next highest if it is in low increments.
Also fitting semiconductor fusing, may offer better protection, if not already used.
Al.
markct 06-23-2007, 02:54 PM i'm not familar with semi-conductor fusing?
Al_The_Man 06-23-2007, 03:50 PM i'm not familar with semi-conductor fusing?
They are the same physical size fuse , but very fast blow, designed to protect solid state circuitry.
Al.
070623-1527 EST USA
markct:
Have you measured your DC bus voltage? What is it?
Have you put a voltmeter on the DC bus and monitored it over time? It will vary as a function of spindle and servo loads, and will rise under heaay dynamic braking. High deceleration and inertia load pumps energy back to the DC bus capacitors. Does your regen resistor, dynamic braking, function and limit the peak DC bus voltage? Does the regen resistor get excessivly hot, should cause an alarm if so, or does it never get hot at all?
How stable is your AC supply voltage and is there good balance? Do you encounter large line transients? Are all your cooling fans working? Is your room ambient temperature high? Do you run at 100% load on the spindle most of the time? Very often at 150% or 200%?
Our vector drive machines range from 1996 thru 2000 and we have had no failures in this area, and few failures at all.
A spindle motor that is not overloaded should be very reliable. However, the failure of a motor driver could damage its motor.
Al:
Specifically what is "semiconductor fusing"? Are you referring to very fast thermal fuses, or some kind of semiconductor device used as a fuse? (edit) You responded while I was composing my question. (end edit)
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Al_The_Man 06-23-2007, 04:10 PM Al:
Specifically what is "semiconductor fusing"? Are you referring to very fast thermal fuses, or some kind of semiconductor device used as a fuse? (edit) You responded while I was composing my question. (end edit)
..
Gar
Semiconductor fuses or Rectifier fuses as some manufacturers call them, are designed to protect solid state circuitry, typically SCR/PWM drives etc, they typically have very fast sweep-out rates and have no time delay element.
Most of the fuse manuf. offer them, Ferraz-Shawmut for e.g.
http://us.ferrazshawmut.com/oem/resources/literature/APPLICATIONS2_44.pdf
Al.
serviceman 06-23-2007, 07:01 PM the newer amps hold up better than the older ones the fuses are replaceable and you can check the amps after replacing the fuse to see if you can put it back in service after replacing the fuse do a diode test on the amp between +hv and - hv and check it against a known good amp with no wires attached to either one
markct 06-24-2007, 06:02 PM wow, thats a lot of electronic stuff i have no idea what you're talking about.
is there a manual i can read???
tecko 06-24-2007, 06:09 PM get an electricion to megger the z axis cable. if there is a brake in the insulation it can blow the card and this can damage the vector drive. If the spindle drive is braking when an axis card blows it could damage the vector drive.. a chance in a million.. but it could happen
markct 06-24-2007, 06:10 PM what is megger?
tecko 06-24-2007, 06:28 PM its a meter that sticks 500 to 1000 volts down the cable and checks for leaks. the cable MUST be disconnected from the drive before testing
HAILINHAAS 06-25-2007, 08:26 AM I would check the Ohms on your regen box .. the black and white cables .. should be around 5.6 .. also there should be three regens for the 15/20 HP vector drive and four for the 30/40 vector drive ... (stove top burners)
markct 06-25-2007, 03:54 PM what is the regen box?
HAILINHAAS 06-25-2007, 03:55 PM It is above the control cabinet. Left side ... looking from the back. Stove top burners.
HAILINHAAS 06-25-2007, 03:58 PM wait .. I read ... 97 machine has a different type of regen. But still will cause problems if not working
markct 06-25-2007, 04:08 PM thanks, when you say stove top burners, do you mean it looks like a stove top burner? should the ohms still be 5.6 for a '97?
is there a manual i can get?
070625-1618 EST USA
On our 2000 SL20 the resistors look like electric range top elements.
On our VF0, also a 2000 machine, I could not look in the box without a ladder. So I did not look. But the resistors are different.
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HAILINHAAS 06-25-2007, 04:35 PM Totally different. Depending on what spindle drive you have the ohms readings will be different. I through that out there because I've seen where a bad regen will destroy other componets. It seems you have something going on. The Z-axis .. does it have the counterbalance tanks on the side of the column. Make sure its working correctly, and not putting a strenuous load on your Z-axis motor .. Check your DC buss periodically and make sure its within 310 to 360V ... your incoming power needs to be stable. If your incoming power is an issue you can get an external transformer that could help. Troubleshooting .. ahhh .. gotta love it.
markct 06-25-2007, 06:17 PM it has a nitro counterbalence, working i replaced it last year.
i'll keep an eye on dc buss. i can check that on the screen correct?
i'll also watch the incomming voltage.
thanks for all your help!
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