[moonman5]

Hi,

Can anyone help?, I have an Interact 1 Mk2 with a Contraves spindle drive unit, The machine is powered from a 15h/p Rotary Phase Converter.

When I try to go above 500Rpm the machine shuts itself down and goes back to the memory test page/reference machine? and then I have to go through the usual start up procedure.

Also sometimes when I do an M05 (Spindle Stop) the same thing happens? I have noticed that sometimes when it stops like this the spindle appears to reverse slightly (opposite direction) only about an angular movement of about 30 dgrs,

If I try to start the spindle at anything above 500rpm it does the same thing and drops all power, The machine WILL start the spindle at 500rpm but nothing more.

Any ideas?.....Thanks for any help.

[Al_The_Man]

I suspect that the acceleration/deceleration rate of the spindle is causing it, starving the generated leg, are you sure you have the controller on the right pair?
Another solution maybe to connect the main controller transformer (T1?) primary direct to the 240v 1ph mains supply, I show 2 10a fuses feeding it, if the drawing is the same as mine?
Set the primary tap accordingly first.
Al.

[moonman5]

I suspect that the acceleration/deceleration rate of the spindle is causing it, starving the generated leg, are you sure you have the controller on the right pair?
Another solution maybe to connect the main controller transformer (T1?) primary direct to the 240v 1ph mains supply, I show 2 10a fuses feeding it, if the drawing is the same as mine?
Set the primary tap accordingly first.
Al.

Hi Al,

No I am not sure? I am still not positive about the wild leg from the converter I am assuming it is the one with the odd high voltage? if this is so, then I have the wild leg on L2 feeding T1 with the 430 Volts thro the 10 Amp fuse?,

I did think of powering T1 with single phase only, I'm just not sure about how to power the rest with the three phases? Do the two "real" phases then go to L1 and L2 and what about the nuetral wire? this is used on the machine at the moment.

Allen. Ps bought you a beer! cheers for all your help, Allen.

[Al_The_Man]

First I would identify the generated leg and make sure any other single phase transformer was NOT connected to it.
You really only need the 3phase for the spindle and your RPC evidently is taking it up to 480, You would have to do some electrical changes but if it still drops out, I would be inclined to bring the 240v single phase pair running the RPC into the cabinet and feed the 1ph transformers off of that supply, the problem is that you only have the one disconnect and that will be supplying the 480 from the RPC.
So you would have to set up some kind of parallel simultaneous disconnect method for the 240 1ph.
I only show a straight 3ph motor and reverser off the supply, I assume the Contraves is set for 480?
Al.
Cheers BTW.

[gus]

You cannot have the control run off of the wild leg

If you start new threads with every problem it is difficult for people to keep track of what is going on

[moonman5]

You cannot have the control run off of the wild leg

If you start new threads with every problem it is difficult for people to keep track of what is going on

Ok Gus, sorry, I see your point so I will stick with this thread untill my problems are solved.

So I have moved the wild leg from the control side, and to make double sure I am now supplying T1 with 240 Volt single phase with a seperate supply from 240 Volt mains, (0-420 Volt disconected from T1 and blanked off) so moving the wild leg is not so important now?.

So now all the three phase goes to the spindle motor (and 380 Volt to the drives).

Now I can get any spindle speed I select from 100-4000 Rpm,....But I still have a problem?

As soon as I stop the spindle (M05) from anything above 500 Rpm it blows the 32 Amp spindle fuse?,

If I stop the spindle at 500 Rpm the spindle stops ok but seems to reverse spindle direction slightly (about 120 degrees) the spindle does not come to a dead stop?. is this normal?

I can get the spindle to run at any spindle speed I just cannot stop the spindle (M05) from speed as it blows fuses?.

I have managed to get hold of some info on the Contraves spindle drive, I am going to run some checks to see if I can find any discrepencies.

Has anyone got any ideas?

Thanks for any help. Allen.

[Al_The_Man]

so moving the wild leg is not so important now?.
.

At least it should not affect the controller now!

Is there a braking resistor that is open or missing, by any chance?
It sound like the drive power cannot take the high current involved in dynamic braking?
Unless there is a parameter or adjustment on the drive to drop the decel rate?
Al.

[gus]

If everything else is now normal, at least you only have spindle drive problems!

Of course those things are not normal, but you had mentioned a burnt component on the drive before, no?

[moonman5]

If everything else is now normal, at least you only have spindle drive problems!

Of course those things are not normal, but you had mentioned a burnt component on the drive before, no?

Hi Gus/Al,

Gus, The component that was burnt/damaged I mistook as a capacitor, This was not the case the component that was burnt was in fact a "Varistor", I believe this is like an electronic shock absorber designed to protect the more delicate components on the circuit board, this kind of adds up, because the one time the fuse did not blow, this part went instead?. I have replaced the damaged Varistor of the exact same spec.

Do you still think the wild leg possition could be a problem?

Al, "Braking resistor"? would that be on the contraves board? should the spindle stop imediatly on an M05?.

My personal feeling is that there will be an adjustment/trim on the contraves board itself, there are several variable pots/resistors on the CRU board, I kind of think it is to high motor field current or something in that area.

The only other thing that still confuses me is that the machine has a nuetral wire (Blue) that is not shown on the schametic? yet is wired in on the plug to the converter and to the machines isolater?

[moonman5]

Hi Guys,

I still have a problem? my machine blows fuses under spindle brakeing (M01).
never blows fuses on acceleration, spindle starts and runs at any given spindle speed up to max, the problem is stoping the spindle.

I am convinced the problem is being cuased by my RPC, it seem that when the spindle is stopping the dc motor acts almost like a generator and pumps energy back in to the system.....possible? I am still getting a slight spindle reversal at the spindle stop like a kind of reverse emf?.

I have checked to see if there is any parameter adjustment and there is not, everything to do with spindle adjustments are done thro the Contraves spindle drive.

I feel sure that if I could slow the spindle more gently, then the fuse problem would go away. I cannot find any kind of brakeing resistor, dont think is anything like this on this drive?, the brakeing is done throgh the the dc motor.

My next thought is perhaps the drive (Contraves) with all of its electronics is "phase sensative"? so is there a "better" possition for the wild leg from the phase converter?.

I have been looking at VFD,s will this make any difference?, sure I will still be left wth a wild leg problem, can you run Dc motors on Vfd?.

Really stuck on this one guys, so any help or ideas would be appreciated,

Allen.

[Al_The_Man]

No DC motors on a VFD.
In all probability the drive is a full wave SCR drive, which if so, fires directly across the 3 phases, these drive often do not take kindly to RPC type supply.
Also these would have dynamic braking, which again is a function of the SCR bridge.
Al.

[moonman5]

No DC motors on a VFD.
In all probability the drive is a full wave SCR drive, which if so, fires directly across the 3 phases, these drive often do not take kindly to RPC type supply.
Also these would have dynamic braking, which again is a function of the SCR bridge.
Al.

Hi Al,

So any ideas on how I can get over this problem? even if it means having to let the spindle run down to a stop from a high rpm.

Allen.

[gus]

I think there is still something wrong with the drive, it should have some kind of internal braking.

I do not know if there is a spindle decel paramter in the heidenhain

[moonman5]

I think there is still something wrong with the drive, it should have some kind of internal braking.

I do not know if there is a spindle decel paramter in the heidenhain

Hi Gus,

Thanks for your input, I dont think that there is a problem with the drive
because the spindle brakes ok, it's just how quickly it stops the spindle, it is such a sudden/harsh stop that I think there is a current rush from the motor that blows the fuses that protect the drive?

Because the machine/drive is setup for dynamic braking this is where the problem starts?.

As I have said, if I could slow the spindle to a more gentle stop then I feel sure the fuses would not blow?

There are no parameters for spindle deceleration, as said in my last post, all spindle control is thro the Contraves spindle drive, There are several pots on the drive unit that can be trimed for optimun running, gonna check the spindle amps and see if they are to high?

I can adjust the acceleration on the drive via the LIN pot, this works fine, it is just the deceleration I need to sus out.

I still believe this is an RPC problem, the drive does not like it?

Allen.

[Al_The_Man]

This is a Heidenhain control, right?
If so I find it difficult to believe that there is no allowance in the control for spindle tuning, what model is the control again?
Al.

[moonman5]

This is a Heidenhain control, right?
If so I find it difficult to believe that there is no allowance in the control for spindle tuning, what model is the control again?
Al.

Hi Al,

It is the Heidenhain 151 A control, I have the original parameter list and also the Heidenhain manual with the list of all the parameters and there discription,

I have checked/read the manual several times but cannot find any parameter related to spindle decel,

I would love you to prove me wrong Al, Please!!

Allen.

[Al_The_Man]

Maybe a stop gap in the mean time if you could write a routine or macro that when called would contain a small looping program that took the spindle down from the existing S value in a series of ever decreasing S values until S0?
Try it at 10sec and then decrease it until you can get the shortest time, not elegant, but it may work if you have macro or similar capability?
Al.

[moonman5]

Maybe a stop gap in the mean time if you could write a routine or macro that when called would contain a small looping program that took the spindle down from the existing S value in a series of ever decreasing S values until S0?
Try it at 10sec and then decrease it until you can get the shortest time, not elegant, but it may work if you have macro or similar capability?
Al.

Hi Al,

Yes I thought of that idea myself in desperation, or even using the cycl def Dwell time command? (although no good unless you know the start and end speed of sindle unlike a Macro). I did have the same problem dropping the spindle to rapidly from say 2500 rpm to 1000 rpm, got the same problems blown fuse with a very aggresive stop?

[Al_The_Man]

When you dynamically brake the spindle the current with the SCR type is reflected directly back to the RPC, you don't have that slight cushion you get with a VFD type with a large internal DC supply.
Is it the same phase (fuse) that blows each time?
Al.

[moonman5]

When you dynamically brake the spindle the current with the SCR type is reflected directly back to the RPC, you don't have that slight cushion you get with a VFD type with a large internal DC supply.
Is it the same phase (fuse) that blows each time?
Al.

Yep, makes sense, sounds like good logic to me, confirms my thoghts on the RPC being the cause of the problem?,

Allen.