[FDavies]

I knew that something was wrong with this machine when I got it, and I have not yet powered it up, but during my clean and inspect I noticed this electrical part ...which seems to be uncoupled from the place it would seem to go.

I have included two photographs. The first photo is of the lower left quadrant of the electrical cabinet, where the part in question is located, and the second photo is of the part, and it's two similar neighboring parts.

Notice in the second photo that there is a rectangular part which seems to be removed from the part above. In the two beside this one, there are similar parts, attached to them.

On each of these three parts is a small pushbutton next to the place where the smaller part is attached.

Pushing the button did not release them. Placing the small rectangular part into where it would seem to fit did not cause it to latch on. Pushing the button did not help.

I can't read the top of the large part without removing it from the rail.

But the face if it is readable. The parts manual labels it as "2K1"
A SIEMENS part...
There are 8 connections...
1L1 3L2 5L3 13no
2T1 4T2 6T3 14no

It also says "10E" and "3TB40"

The part which fits into it is labeled:
Murreektronik
RC-S01/220
22011
3TX 6406-DC

And is called "2RC6" in the parts manual.

...I have only managed to locate these parts in a diagram in the parts manual and not any other page ...so far.

Now, armed with the number 3TB40 I searched Siemens' site and it may be a motor starter, but I could find nothing more than that, ...if in fact that is correct.

The part reminds me of a breaker in having a part release and thus disconnect something. But I am at loss as to how to re-set it. It does not look to be broken in any way. Perhaps it is a relay and a breaker combined? Or a momentary starter switch with a breaker? I am assuming it is magnetically held in place and that maybe a signal would need to be sent to relatch it? Just don't know, and it's too easy to make silly guesses I really have no use for.

Of course I will now ask MAHO, and post the results back here.
And I may ask SIEMENS too.
But first I'll ask YOU!

[toolnuts]

It looks like a relay (the three big square items on the right ) or a contactor (same thing).

If you have the wiring diagram or schematic you could trace/track it down.

If you send me a larger photo I can probably tell you what it is.

Paul

[toolnuts]

Given the nomenclature you provided I would say it's a three phase contactor -

L1, L2, & L3 are the 3 phase lines coming into the contactor (forget the leading digit). The T1, t2, & T3 are the outgoing lines to whatever the relay/contactor controls.

A simple way to tell is use a multimeter and test continuity from L1, L2, L3 to each of the main breaker lines (L1, L2 , and L3) coming into the power panel. Test L1 to L1, L2 to L2, and L3 to L3 and you should get continuity on each.

On the 'T' side either trace the wire to the device or use the multimeter on the diode 'beep' setting and start fishing around until you ge a beep when you locate the correct device. There should be similar contactors that you can look at (in your machine) to see how the pieces fit together.

Good luck

Paul

[FDavies]

Given the nomenclature you provided I would say it's a three phase contactor -

L1, L2, & L3 are the 3 phase lines coming into the contactor (forget the leading digit). The T1, t2, & T3 are the outgoing lines to whatever the relay/contactor controls.

A simple way to tell is use a multimeter and test continuity from L1, L2, L3 to each of the main breaker lines (L1, L2 , and L3) coming into the power panel. Test L1 to L1, L2 to L2, and L3 to L3 and you should get continuity on each.

On the 'T' side either trace the wire to the device or use the multimeter on the diode 'beep' setting and start fishing around until you get a beep when you locate the correct device. There should be similar contactors that you can look at (in your machine) to see how the pieces fit together.

Good luck

Paul

Thanks Paul,

I finally spotted the part number in a parts list in the Parts Manual.
Here is all that it had to say on the subject:

Name | parameters and Type

2K1 Luftschuets | 3TB 4010 GAG1 110v 50/60Hz
2RC1 Loesch block f. Motor | HRC3/047-400


The first part, 2K1 is the larger part, and the smaller part which plugs into it is the 2RC1. These are MAHO diagram numbers.

The 2K1 is made by Siemens and the 2RC1 is branded Murreektronik. These seem to differ from Luftschuets, and Loesch block f. Motor respectivily as listed in the manual (and above.)

Your thinking about it being a contactor or relay makes sense. The question is what does it do, and what is that piece attached to it for? I suspect you are right about it going to one of the main motors, and your suggestion for determining which one, seems logical and practical.

A schematic diagram would sure come in handy about now.
MAHO Circuit Diagram 67032 is what I'm looking for, and I have not heard back from MAHO on this request although they stated earlier that they did not have anything on the machine.

I am still puzzled about plugging the small part into the big one. Pushing the button did not release the other similar parts, nor did it effect mating them together. That is why I suspect it to be a circuit fault mechanism, ...and I'm just hoping it does not point to a bigger problem.

Time will tell, and in the mean time I'll try to locate some spec's on these parts and an explanation of how they are used on the machine.

It would be nice to be in contact with some other shops running the same machine. Perhaps I could get a copy of the circuit diagram then.

[FDavies]

Yes, I see this labeling on the machine connected side of the terminal block.

Further inspection led me to note that the '35' labeled portion may have been due to the label itself having migrated from somewhere else in the machine, and just by chance having landed in the proper Murphy's Law Place, i.e. aligned correctly with and directly over a label area of the same size.

I see nothing in the transformer cabinet (not shown) area looking like an uncoupled or empty terminal, so I am assuming this is the correct terminal block, at which power is introduced to the machine. Nearby, there are two circular cut-outs in the floor of the electrical cabinet where I assume the electrical power cabling entered the machine.

Thank you!

Ah Ha!!!

Cleaning is a good thing. While doing so, I cam across the markers which had fallen off the terminal block.

The terminal block is actually marked:
L1 L3 L2 N PE (when viewed from the open cabinet door)
... matching those on the other (machine connected) side.

Nothing is connected to the N terminal, but PE is grounded to the chassis.

[toolnuts]

Most good machines have a numbering scheme to their wiring, and often all you have to do is look for devices that have the same numbers on the wire. The numbers can be a tape, or a metal tag, or actually marked on the wire itself. Then do a continuity check between the wires with the same numbers.

If you look at the other contactors, and there should be several of them, you should be able to understand how the pieces fit together. Imitation is the most sincerest form of flattery.

Another clue would be the size of the wires that go out of the contactor. The larger the wire the larger the motor. Another place to look (or continuity check) is at barrier strips. you can usually find them where the wire bundles come into the junction box. Do the 'beep' test from the mistery contactor to the barrier strip, and then see which bundle the beeped wires go to, then follow them to the end (motor, etc..).

Paul

[FDavies]

I've identified the parts, but I am still looking for more information...

I am attaching a better photograph of the contactor (the place where the red "K5" tag is, is where the surge suppressor fits in) along with a photo showing a similar part (22E instead of 10E) with the slot clearly visible.

I have learned this about the surge suppressor...

Surge suppressor for 3TB40 to 43 designed to suppress noise generated by the contactor coils.

Type 3TX6 406-OH is designed a free wheeling diode; while type 3TX6 406-1 is a non-linear resistor (varistor) which is capable of suppressing switch-off surges so that these do not affect electronic systems installed in the vicinity of power circuits. The varistors are designed for use at contactor switching frequencies as per Catalog 1\S2

...Still learning.

...I just updated this to include a photo with the surge suppressor installed in a similar contactor.

[toolnuts]

N = neutral
PE = earth ground
Just like your house wiring.

The surge suppressor is not for noise but to suppress the large voltage spikes that occurs when you turn off the motor and the inductance produces back EMF of many 100's (or 1,000s) of volts trying to stop the collapsing field. It there to protect the relay points from pitting from the backlash from the motor inductance. It like a miniature EDM when this happens, and the points don't like this on bit.

Paul

[AndreasL]

Thank you for the picture.

Really great "thing" to have. Awsome!

But why, why, why paint it yellow...and not "Maho green"?
Such a divece, that rare, deserve that I think.
But thats me and I'm (unfortinatley) not the one with a 5-axis...I only have 4...and dont even know how to use them in a proper way.

Keep us posted with youre progress and let us know the full potential of this 2-axis table. :banana:

[FDavies]

Thank you for the picture.

Really great "thing" to have. Awsome!

But why, why, why paint it yellow...and not "Maho green"?
Such a device, that rare, deserve that I think.
But thats me and I'm (unfortunately) not the one with a 5-axis...I only have 4...and don't even know how to use them in a proper way.

Keep us posted with your progress and let us know the full potential of this 2-axis table. :banana:

Why yellow?

Everything in my shop is painted green. It seemed a nice bright contrast, and it is after all a moving part.

Well, that and the fact that I do not have any MAHO-green paint. Any suggestions on matching MAHO's green colors in a rattle can?

The 5th-axis is kind of cool, but it may be a hassle mounting the work to a vertical surface rather than a horizontal one. Perhaps there are some tricks to doing this that I will learn in the future.

[FDavies]

N = neutral
PE = earth ground
Just like your house wiring.

The surge suppressor is not for noise but to suppress the large voltage spikes that occurs when you turn off the motor and the inductance produces back EMF of many 100's (or 1,000s) of volts trying to stop the collapsing field. It there to protect the relay points from pitting from the backlash from the motor inductance. It like a miniature EDM when this happens, and the points don't like this on bit.

Paul

That was a very good explanation!

Further examination has resolved the mystery. The surge suppressor has two small tabs on it which hold it into the slot on the contactor. One of these tabs is missing (and sheared off giving the appearance of not being broken.) So, a drop of super glue should hold it in place nicely. The push button on the contactor seems to have nothing to do with fitting or holding these two parts together.

[AndreasL]

may be a hassle mounting the work to a vertical surface rather than a horizontal one. Perhaps there are some tricks to doing this that I will learn in the future.

Yellow or not...
If you find out its a PITA to mount your work pieces, send me a PM and I will relief you from the pain any day in the week! :bat:

Cant wait to see this one in full swing.

[FDavies]

I've just talked to the MAHO Doctor and learned that a transformer may be required to convert the incoming voltage to the European standard of 380 volts.

I guess the next question is where are they and how much?

Any surplus out there folks?

There was a hand written piece of paper on the power supply module indictaing it had been set to 220 volts, but I am now assuming this is related only to an internal power. ...I Don't really know for sure!

What if it is hooked up to 220 and its expecting 380? Will anything work? Will anything break? How about vice versa? 380 volts on a 220 circuit would not be a good thing.

How can this be known or figured out?

A wiring diagram would be nice. I need an Electrical Circuit Diagram E-6732 for a MAHO mh600C (w/2-axis rotary table.)

So, where does the transformer go? Single phase 220 to 380 going to the phase converter, or 3 phase 220 to 380 transformer from the converter to the milling machine? Either? Which is least expensive? (Possibly a dumb question.)

[toolnuts]

Hello again,

Ah yes European voltages.

There is no single phase to three phase transformer unless you count a Scott 'T' transformer. But you would have to make a second phase with a bunch of capacitors - it's a form of static phase converter.

You will need to get a 240v to 380v three phase transformer. Don't try to run the machine on 240v unless there is transformer re-configuration lugs. For US machines there are usually labels of where the jumpers should go to re-configure from 240v to 480v. In your case you would need a 240v to 380v jumpers.

First you need a phase converter, and I would recommend a 'Phase Perfect' converter. However they are pricey. I assume your machine requires compressed air to run, and so you will need to be able to run a compressor at the same time as your machine is running. If your compressor is three phase you will need to size the phase converter accordingly. Air compressors are the worst to start and they require a lot of starting current.

Next you will need the three phase 240v to 380v transformer, unless as previously stated, you have a re-configurable transformer. The amount of KVA should be listed on an exterior electrical specification plate. Power transformers are sized by their KVA. (KVA is the same as kilowatts for a purely resistive load only (not motors, etc.))

If you try to run your machine on any but the design voltage you will most likely be very unhappy with the results and so may the fire dept..

How many machine are you going to run on three phase, and what is the range of horse powers? If you want to use a rotary phase converter this may be a big factor.

Paul

[MahoDoctor]

Your machine will require a 20KVA 3 Phase transformer. They are usually multiple voltage input with 380 volt secondary. The secondary will have + or - 10% taps. Maho recomends 380v minus 0v or up to +10% I have most copies of electrical prints on all Maho machines and machine constant copies for most machines. I have worked on Maho Machines since 1980. I worked for Maho and DMG. WWW.MahoDoctor.com You will have to run 5 wires to Maho 3 hot legs with a neutral and a earth ground.

[FDavies]

I spoke with a worker today from the shop which previously had the machine.

He told me that the machine had been modified and it was and is ready to be hooked up to three phase 440 volt power.

They used a transformer to convert from 220 volts to 440 volts and he will look into selling it to me. (It is still there, and they may not have a use for it.)

Well, that answered my question about the voltage although I do still need the transformer and a phase converter.

I also asked about the missing electrical diagram and so there is some hope that it may be found. DMG has yet to send me a price or confirm that they have found the diagram.

[toolnuts]

Yes, you still need the phase converter to convert your single phase into 3 phase.