Hurco KMB-IS CNC update

Hi Robert,

In the left hand cabinet, there is what appears to be a single contactor. Don't know what its for.

And, I definitely don't have that Hurco T2 transformer. The servo drives have been upgraded. Assuming the transformer was upgraded too.

At this point, what I need to do is trace some of wiring and get an idea what's connected to what. For example, I can determine where the servo drive supplies are connected. But I'm not going to do this until the machine is located in my garage. Don't know when the machine will be moved.

Yes the thing to do now is trace backwards from the Max-430's. I am sure they are 80V input and not 110V, so I would trace backwards to see where the wiring goes. You can always check the front of the 430 amp to make sure it does state 80-85V input, just in case Electro-Craft made a change and started using 110V as this would eliminate the transformer... I doubt this, plus when I went back to your picture and zoomed in, it appears to say 80-85.

Tracing backwards will show what is going on. It should go backwards from the Max-430's to the servo transformer and the servo transformer power will go to back to the contactor that feeds it. The contactor should be there if it was done correctly as that would power & shunt the amps.... but you never know what someone has done before you. They may have had the amps hot all the time eliminating the contactor, I don't believe this, but you never know what was done. Me and you both are assuming that everything was wired correctly when it was working. It could have been re-wired during the upgrade and everything installed in the left cabinet when working, but some of it taken out when trying to fix whatever problem.

Nothing like following behind someone that doesn't do it correctly LOL. You may be cleaning up someone's mess... let's hope not.

I am super slammed today. I stayed up all night doing paperwork and now trying to get everything put together for tomorrow (my deadline is Saturday). I may or may not be around as much today/tonight, but will try to get back when I take a break.


Robert

Just realized that you stated about the single contactor in the left panel... (I have too much going on with work and missing some things on replies)

Ok let's assume they did change up the wiring and the transformer off the back is the servo trans and not the step-down.

I still have my doubts and think that big one is a step-down, but lets say its the servo transformer. They may have it where the wiring goes from the max 430s to the big brown trans hanging off the back and then into the left cabinet to the contactor. You could also look at the contactor and see if it is going to the transformer. Since there is only one contactor, lets assume they are using it for the servo amp (ACC contactor on schematic) and that there was NO flood coolant pump option.

In fact, while typing that it just hit me that seems like the flood coolant is a option and you may not even have had that contactor ever in the machine. Yours may not have had flood coolant, but mist coolant only. I will go back and check my paperwork later tomorrow and check to see if it was an option or standard... almost positive it was option now that I think about it and I may have been miss-guiding you on saying 2 contactors. (See how easy it is to get miss information LOL)

So I would trace and see if this may be how it was wired at the end. I am sure Hurco originally had the contactor in the right cabinet, but once again you are coming behind someone and need to keep it in mind.

I keep thinking everything is correct from Hurco. But I need to stop assuming and start thinking like the shop manager who had their plumber or carpenter re-wired it for them LOL.

Talk to you later,
Robert

Leith,

There is one thing good that has came out of this for me....

They would have hung that large transformer off the back of your machine to get good airflow, plus it was probably not the same size as OEM and would not fit wherever the OEM was located. So it's a good possibility size is what made them put it back there. Someone above them or the procurement person was told to get a transformer. So they got the cheapest thing available and when it came in began the debacle of where to mount it. Of course, all speculation, but I have seen this slow train wreck happen before in other machines.

Ok for me, because of checking out that back cabinet that is sealed made me realize I need to go check out that fan that is directly below the transformer. I need to keep a eye on it and I am probably going to add a thermistor to the cabinet and monitor through LCNC to shunt the amp if temperature spikes. I will either get the correct EtherCAT terminal for the thermistor or wire it into a input like a E-stop to simply shunt the amps.

To be honest, it would have never come across my mind, but when I was looking at the pictures again it hit me about temperature when I saw the fan. You may have saved me from a burn out down the road


I will be back,
Robert

There is the DC supply transformer. Which appears to have been moved to improve cooling. I have a schematic and all make sense.

The serial number label on the machine says 220V 3 phase. The quill motor is 3 phase 220 or 440. OK.

Now I need 120VAC input for the DC supply transformer and ~80VAC for the servo drives.

I think there is only one more transformer. The brown one mounted on the back. It looks like there is a single pair of input wires and a single pair of output wires.

The brown transformer is relatively large, but only about 1/3 of its volume is windings/core. The top and bottom thirds are empty. I think the top and bottom serve to help cool the core.

I've got one transformer, but I need two. Perhaps there was another that was removed? Don't know.

Probably the best way to solve the mystery is trace the wires. Where do the servo drive AC input go? Where does the 120 VAC input for the DC supply go?

Seems like I'm missing a transformer. We'll see.

_big_ wrote: The brown transformer is relatively large, but only about 1/3 of its volume is windings/core. The top and bottom thirds are empty. I think the top and bottom serve to help cool the core.

That might be a choke/line filter/current limiter.