Why is our Mazak smoking/eating "spark killers"?

[rmarchjr]

Strange thing happened Saterday.

1999 Integrex 200SY - Fusion MT, ran great made parts. While doing next program got a hydraulic failure message. Walked over to the coolant sub panel and noticed smoke! - talk about an OH S**T moment.
Shut the machine down, opened the cabinet to find a "spark killer" - (capacitor) had fried itself. I had heard these things can fail in 12-20 years - they just go bad with time.
The spark killer was original and wired into the hydraulic motor starter.
Next to it was another one for the coolant starter, and another for the chip conveyor.
The spark killer connected to the coolant motor starter was obviously overheated but not smoked.
We replace them all. Also checked and cleaned all contacts. Turned on and observed no/minimal spark on each motor starter. Check voltage and amprage for all motors, also rechecked main power 224,226,224 - all OK.
We proceeded to blow up the new one about 15 minutes later - same hydraulic motor unit and the new coolant capacitor was getting hot as well.

The machine has been operating on this power for about one month.
Called Mazak who said they never heard of this happening ever, we checked every voltage and amp again with them as instructed - All OK. Grounds good.
Mazak service advised removing the capacitors.
We did and the machine is running perfectly. (20hrs so far)

I don't feel great removing an electrical safety that Mazak designed for a reason. I am NOT very good with complex electrical stuff

Does anyone have any advise, similar issue, idea what could cause this?

[Al_The_Man]

There are a couple of types, if this is the RC snubbers used across either or both the coils and the 3 phase itself, these are usually rugged components and do not generally overheat.
The only thing I have seen have signs of overtemp is the MOV type, Metal Oxide Varistor.
These will suffer heat damage if the supply voltage happens to be close to the over voltage operation point.
Al.

[rmarchjr]

Al thanks for the reply, here are some pictures of the components-

So we were running for a few days then got a slideways lubrication alarm. Found the "shaded induction" way pump not pumping. I had "granger" do an emergency opening so I could get a temp. replacement motor. I made a quick motor mount out of a 6061 T6 block I had laying around. It is running for now.

Do you think that the motor failure is related? Can you think of anything that could possible cause both of these electrical issues?

When we hooked the machine up we had the Mazak transformer/power switch tapped to produce 115, 116, 115 for voltage. Mazak recommended we retap it to increase voltage and we did moving it up to 224,226, 224. I was thinking about changing it back to the lower voltage, what do you think?

Pic 1 - is the description of the motor which just failed.
Pic 2 - is the "spark killer"
Pic 3 - is a brand new one after running for 15-20 mins - you can see it was well on it way to failing
Pic 4- is the motor which just failed
Pic 5- is the temp motor mount I made for the granger motor.

Thanks

[Al_The_Man]

Most equipment coming out of Japan is rated for 200v +-10%.
Notice the motor is rated at 100vac.
I would tend to try and keep the 200vac control as close as possible, the 3 phase snubber is only rated at 250v, so if you have higher than normal voltage and then you get a good spike come through it does not allow much margin.
Al.

[Al_The_Man]

BTW, If you move the primary taps up to a higher voltage, this lowers the secondary output.
As opposed to moving secondary taps up which will increase the voltage.
Al.

[rmarchjr]

This machine is killing me...

OK, we got a new lube assembly and it stopped working after about 4 hrs.
Re tapped the transform (set at 220 In - we have 191 out.)
Pump works, then stops. Also today after the retap - we had one motorstarter jump around bit for 3 seconds on startup.
No voltage to the pump only 1.3volts - we had tested before the retap @ 106V. The main control box has a panel AP1 and an SSR was not lit. Removed the panel and found the back of the board "dark brown" in a few places including the SSR- 4wire. The soder looked - melted?
We have a replacement board coming, and the $33 dollar SSR- maybe can save that other board.

What is going on? I don't understand how the machine could work for a month then have all these "unrelated" electrical components fail. It also appears that the original lube oil pump was not faulty.
This AP1 board had connections to many major electrical components but is this the problem or another symptom of some other problem?