Required voltage for this large saw (German three phase schematic)

[Kurtisinger]

Hi.. I am trying to figure out the required voltage for an Austrian built saw. I am not very good with AC plus the schematics are in German, I think, which is further confusing the matter. Here is the saw: http:/altpubad.com/Temp/1265-1994.pdf

I assume it uses three 240 lines but thought I better check. Any help would be greatly appreciated.

 

[jim hardy]

hmmm.

from the manual

from the picture of motor nameplate

so the motor can be connected delta or wye
to run from either of a nominal 220 or 380 volt three phase source
the first two sets of numbers are for 50 hz the second for 60 hz and i don't know which you have.

note that 220 X √3 = ~380,
so if you have either of those voltages you can make the motor happy.

You should find small numbers on the motor wires with letter "T"
and a diagram for the motor that looks similar to one of these , usually it's mounted on the motor near the connection box.

http://catalog.wegelectric.com/img/Wiring_Diagrams.pdf

wire it delta (Δ) for 200 or 230, Y for 350 or 380.

good luck !

old jim

 

[GrahamN-UK]

Hi.. I am trying to figure out the required voltage for an Austrian built saw. I am not very good with AC plus the schematics are in German, I think, which is further confusing the matter. Here is the saw: http:/altpubad.com/Temp/1265-1994.pdf

I assume it uses three 240 lines but thought I better check. Any help would be greatly appreciated.

I'm writing this as background information. As you say you are not very good with AC you really need to get this saw wired in by an industrial electrician experienced in 3 phase work in your jurisdiction. A 3 kW 3 phase motor connected to a circular saw blade is not a system to learn AC on for beginners.

It is a three-phase system. The motor runs on various voltage ranges as shown in the photo of the rating plate. The relevant part is:

Delta/Star 200-220/350-380//220-230/380-400 V
50//60 Hz

The ratings to the left of '//' are for 50 Hz operation, to the right are for 60 Hz operation.
Then for each side the first rating is for delta connection and the second rating is for star connection.

According to this diagram:

https://www.electriciansblog.co.uk/...r-star-and-delta-wiring-and-link-connections/

your motor seems to be strapped for delta operation, so 200-220 or 220-230 V depending on your supply frequency. (The straps are the horizontal copper links at the back of the motor connection box.)

Which country are you in? Do you have a 50 Hz or 60 Hz supply? What 3 phase supply voltage(s) do you have available?

In the control box there seems to be a floating wire nut and one cable (the supply cable?) has black, white and green conductors connected to 3 phase terminals (L1, L2, L3 on the left) which looks like a US 1-phase cable pressed into 3 phase service (against code). Are you in the US?

Was the control box supplied with the saw? I can't see it in the saw pdf file. Did you get any documentation for the control box?

 

[Kurtisinger]

Thank you Graham. I'm in Alberta Canada. I think three phase here is 60 hz. The schematic that I have attached is all that I have for that saw so far, except for the doc at http://altpubad.com/Temp/1265-1994.pdf. I'm thinking that the motor of course runs on three phase and there is an automated counter balance that runs on two phase, and a small transformer that runs on single phase that powers the sensors. Does that sound like it makes sense according to the schematic?

 

[GrahamN-UK]

Thank you Graham. I'm in Alberta Canada. I think three phase here is 60 hz. The schematic that I have attached is all that I have for that saw so far, except for the doc at http://altpubad.com/Temp/1265-1994.pdf. I'm thinking that the motor of course runs on three phase and there is an automated counter balance that runs on two phase, and a small transformer that runs on single phase that powers the sensors. Does that sound like it makes sense according to the schematic?

Yes, your supply frequency is 60 Hz for both single and three phase.

Canada seems to have a choice of 208 V, 480 V or 600 V for its 3-phase supplies. Do you have 208 V 3-phase available to you? That would seem to be compatible with the way your motor is strapped, just under-running it slightly on the 220-230 V setting. The motor isn't suitable to operate on 480 or 600 V supplies.

Has someone else already been using this saw in Canada or did you import it from Austria? The motor would have needed to have been strapped for 380 V operation in Austria.

The counter balance and sensors you mention would explain why there is a control box to wire this all up. Although the control box picture is too fuzzy for me to see all the details, there is something in the lower right corner labelled '100 VA' which could well be the sensor transformer.

Was the control box supplied already cabled to the motor and other equipment? Was the cable feeding power to the control box supplied? Does it have a plug fitted and, if so, what sort is it?

 

[Kurtisinger]

Thank you Graham. The saw came from a local lumber store. Turns out that a pin dropped out of the mechanism that locks the saw into place before it will even turn on. I am assuming that a janitor came along and swept the pin up and left some dummy thinking that there was an electrical problem as the wiring in the motor has obviously been messed with. The main control panel which is factory equipment looks untouched. The cable hanging out of it was cut off. Their loss my gain. In this neck of the woods the saw is worth between $7500 to $10,000. It was fun to move though as it is 16' in length and 8' in height and weighs 1000 kg.

 

[Kurtisinger]

Thank you Jim. Sorry for my lagg time responding to your post. For some reason the quote and reply buttons were not highlighted on your post and could not be clicked on until now. I figured that you had disabled responding. Anyway, between you and Graham I am learning a lot about three phase and still looking some stuff up. One of my main points of confusion was all of the possible voltage configuration's listed on three phase motors which I now know how to read.

Thanks again Jim.

 

[jim hardy]

I am learning a lot about three phase and still looking some stuff up. One of my main points of confusion was all of the possible voltage configuration's listed on three phase motors which I now know how to read.

Great ! That makes us feel good, when somebody gains by participating here.

I've no idea why the trouble with buttons - computers are just that way..

Thanks for the feedback - let us know when you've got it running?

old jim

 

[jim hardy]

@Kurtisinger
i can almost make out the T numbers on your motor leads...

and i think i see twelve motor leads in there.
That's the most versatile arrangement for it gives you access to both ends of all six windings.
Also it's the most baffling to figure out.
Fortunately there are industry standards for marking the wires

Before rewiring make yourself a sketch of how you found it wired , with the T-numbers..

if indeed i see two groups of three twisted together and taped
i'd guess it's wired this way, for the higher voltage 380

if it is indeed wired for 380 your symptom will be
it runs on 230 but is slow to start,
lacks power,
and when working hard will pull way more than nameplate amps and might even stall.

Got a clamp-around ammeter ?@GrahamN-UK what do you think ?old jim.

 

[GrahamN-UK]

...and i think i see twelve motor leads in there.
That's the most versatile arrangement for it gives you access to both ends of all six windings.

@GrahamN-UK what do you think ?

I can certainly see lots of leads in the picture of the motor but many of them go to the light brown connector block or the flying blocks wrapped in duct tape (hmm...).

I think the connections to the motor field windings are in the 2 x 3 block with visible straps at the back of the connection box. This suggests that each phase has a single winding rather than a pair of half-voltage windings.

This is corroborated by the rating plate which has the range of voltage options expected for a 6 terminal motor. If the motor had 12 terminals for split-phase windings we'd expect to see an extra voltage line containing ratings for 110-115/190-200 V at 60 Hz and we don't.

Fortunately we don't need this much detail. Kurtisinger has told us the saw was operating in a local lumber store, so it's already been operating in Canada and the motor should therefore be already correctly strapped for Canadian operation. If the motor to control box wiring is still intact all that should be needed is to identify a suitable 3-phase 208 V socket supply and replace the supply cable to the control box.

It shouldn't be necessary to change the motor wiring, which is just as well, as it looks a right mess. (I hope there's a cover available for that motor junction box, or one can be made.)

We have table saws like this in my local DIY stores. It's useful to have large sheets cut accurately and neatly to the sizes I need (as well as sizes small enough to fit my car - I can't take an 8' x 4' sheet).

 

[jim hardy]

(as well as sizes small enough to fit my car - I can't take an 8' x 4' sheet).

Ahhh the Great American Dinosaur..

Mine will handle 4X8 , but barely...

good observations on that motor.

old jim

 

[GrahamN-UK]

I can certainly see lots of leads in the picture of the motor [junction box] but many of them go to the light brown connector block or the flying blocks wrapped in duct tape (hmm...).

I assume the extra leads run to the counter balance and sensors mentioned earlier. If not, perhaps Kurtisinger could tell us where they go?

 

[Kurtisinger]

Okay sorry.. Just finished one of the longest deep freezes here in recent history for this area. Been running around like a chicken with the head cut off chasing snow and frozen equipment.

You are right Graham all the extra wires there go to the automated counter balance and sensors. Unfortunately, as you can see, the wires going to the the windings are only color coded. The orientation of the motor in the photo is with the drive facing down. This is going to be fun, especially because the only thing that I can presently identify in the control box is the transformer and the red lock out switch that is beside it. The saw is sitting on the other side of town and I ran out of time to check the continuity on the windings. Hopefully I will be back there soon.

Yes, there is a cover for the motor.. : )

Thank you two for helping figure this out and teaching me something it is much appreciated.

 

[Kurtisinger]

Oops.. sorry, I don't have a wrap around ammeter that works right now and there is no diagram on the motor like every other three phase motor that I have seen so far. I'm starting to think the Austrians like proprietary equipment.

 

[jim hardy]

You are right Graham all the extra wires there go to the automated counter balance and sensors. Unfortunately, as you can see, the wires going to the the windings are only color coded.

Thanks Guys

now i see it
black blue and brown

@GrahamN-UK was right i'd say , looks delta to me,

Last motor i looked at was a 12 lead with numbers printed in white on black wires.
They looked just like those leaving your junction box in the conduit...
Sorry for the blooper.

I expect your saw motor will be happy on 208 or 230 volts.

old jim

 

[Asymptotic]

Several observations.

In the control box there seems to be a floating wire nut and one cable (the supply cable?) has black, white and green conductors connected to 3 phase terminals (L1, L2, L3 on the left) which looks like a US 1-phase cable pressed into 3 phase service (against code). Are you in the US?

1. It is unsafe to use the pictured 3 wire (2 wire + ground) cable in the mains supply. Without a grounding wire between saw and power source the machine frame can float above ground potential, and you may get shocked (or worse) if your body connects the machine frame to ground.

2. The electrical schematic PDF file In your first post isn't viewable, and listed as 0 bytes in length.

The main control panel which is factory equipment looks untouched.

3. Your photos in post #13 suggest it has been messed with quite a bit.

• Relay K4 doesn't have any wires connected to its contacts.
• Several wires are terminated under a wire nut (not something a reputable panel builder would do).
• The unlabeled control relay is different than the other three. A newer series, perhaps?
• A newish-looking Hammond control transformer in combination with a black witness mark directly above it suggests the original transformer had failed.

It's a fair amount of work, but I'd trace out and sketch an 'as-is' wiring diagram, then compare it against the 'as-built' drawing.

 

[Kurtisinger]

Can't upload pdf''s for some reason. http://altpubad.com/Temp/EL2511029.pdf

 

[Kurtisinger]

Hi Graham. Not to sure what you mean that k4 doesn't have any wires connected to it. I see 4 wires connected to the top and at least 4 to the bottom.

I'm starting to think that the wires in the motor that are twisted and taped along with the wire nut in the control panel are to configure for manual or automatic operation. There is a sign beside the start button that says no manual operation so it must presently be set for automated mode.

Guess all that I need now is 3 phase power and a proper cable.

Thank you guys.. : )

 

[Asymptotic]

Not to sure what you mean that k4 doesn't have any wires connected to it. I see 4 wires connected to the top and at least 4 to the bottom.

Asymptotic, not Graham.

My mistake. I meant the relay labeled -K2, which appears to actually be relay -K5 (the wiring diagram shows relay mechanical line-up on page 4; the rightmost one is K5). -K5 is described as the moving grid relay, and N.O. contact pole #13/14 on it is in the saw motor start/stop circuit.

Good luck!

 

[Kurtisinger]

Hi Asymptotic.. Sorry, I am still getting used to how this forum works. Now I see what you are saying about A2. That is interesting.

Thank you

 

[jim hardy]

Aha !

Translations around page 14...

 

[Kurtisinger]

Looks like maybe the k2 sticker is on the wrong component.

Also, page 17 shows how to configure for automatic or manual mode, and how to switch the system up from 200/230 to 400. I think...

 

[anorlunda]

Also, page 17 shows how to configure for automatic or manual mode, and how to switch the system up from 200/230 to 400. I think...

I think you're missing the significance of what @Asymptotic said:

Your photos in post #13 suggest it has been messed with quite a bit.

If that is true, then you can't believe anything the manual says. You're in unknown territory.

 

[GrahamN-UK]

The main control panel which is factory equipment looks untouched. The cable hanging out of it was cut off.

Oops, missed this earlier. Is this the cable between the control box and the motor junction box that has been cut through? Awkward, if so. Still, the individual wires seem to be numbered at both ends which should help establishing where the replacements will need to go.

 

[Kurtisinger]

Hi Graham. Sorry, the cable hanging out at the bottom of the control box looks like a standard 110, 3 wire cable. Black, white, gray wires. The wiring from the control box to the rest of the saw is intact.

 

[Kurtisinger]

Another three phase project mystery. I built this platform so I could easily switch up motors/pulleys for testing purposes. When I put this Weg 21 motor on it and started it up, it was producing 240 on all three legs at a little over idle, no 12 v boost required. I ran it for just long enough to get a reading, shut it down and checked the temp of the motor and caps, all were cool, then I fastened the Caps together and grounded them. It was the last time it produced more than 9v ac and that was with a 12v boost to the Caps otherwise it would only put out 3-4 volts. I checked the continuity and there was nothing between W1 & W2. It appears to me that the motor has been rebuilt or at least apart because some of the fins on the rotor are bent and almost all of them have been scuffed on the corners. There isn't any scuffing to the case and the bearings are tight. I am wondering if it was my setup that caused it or if it was already on its way out the door. Of coarse I realize now that it would have lessened the mystery if I would have checked the ohms first. I know better now.

Also, if a three phase motor will run on two sets of windings shouldn't it produce electricity on only two sets of winding?

 

[GrahamN-UK]

...

1. It is unsafe to use the pictured 3 wire (2 wire + ground) cable in the mains supply. Without a grounding wire between saw and power source the machine frame can float above ground potential, and you may get shocked (or worse) if your body connects the machine frame to ground.

Agreed. It needs to be replaced with a proper 3-phase + Earth cable. Earth continuity should be checked from the supply to the control box and on to the saw assembly.

A newish-looking Hammond control transformer in combination with a black witness mark directly above it suggests the original transformer had failed.

In the new pictures (thanks) I can't see any strapping on the T1 transformer for 240 V operation (top row) or 120 V operation (bottom row). The circuit diagram (p5 of EL2511029.pdf) shows a transformer without split windings and hence not requiring strapping. Although it might be a trick of the photograph I wonder if whoever replaced the transformer copied the connections from the original transformer without realising the replacement required strapping (as shown on the white label). Failing to do this means there would be no power to the relays/contactors in the control box and the saw wouldn't work. That might be an additional reason for the previous owner disposing of it, as well as the missing pin mentioned earlier. (I previously speculated that the transformer was powering the sensors but it's now clear from the circuit diagram that it's powering the control box.)

There are 3 fuses shown around T1 on the circuit diagram but I can't see any of them in the pictures. Perhaps they are on the door of the control box?

It's a fair amount of work, but I'd trace out and sketch an 'as-is' wiring diagram, then compare it against the 'as-built' drawing.

As a minimum I suggest printing off the circuit diagrams and checking the wiring against them to see what has changed. If there are lots of changes it will be easier to follow Asymptotic's suggestion and sketch a new diagram.

 

[Kurtisinger]

Agreed. It needs to be replaced with a proper 3-phase + Earth cable. Earth continuity should be checked from the supply to the control box and on to the saw assembly.
In the new pictures (thanks) I can't see any strapping on the T1 transformer for 240 V operation (top row) or 120 V operation (bottom row). The circuit diagram (p5 of EL2511029.pdf) shows a transformer without split windings and hence not requiring strapping. Although it might be a trick of the photograph I wonder if whoever replaced the transformer copied the connections from the original transformer without realising the replacement required strapping (as shown on the white label). Failing to do this means there would be no power to the relays/contactors in the control box and the saw wouldn't work. That might be an additional reason for the previous owner disposing of it, as well as the missing pin mentioned earlier. (I previously speculated that the transformer was powering the sensors but it's now clear from the circuit diagram that it's powering the control box.)

There are 3 fuses shown around T1 on the circuit diagram but I can't see any of them in the pictures. Perhaps they are on the door of the control box?As a minimum I suggest printing off the circuit diagrams and checking the wiring against them to see what has changed. If there are lots of changes it will be easier to follow Asymptotic's suggestion and sketch a new diagram.

Good eye Graham, thank you. Looks like I am going to learn more about ac and three phase then I thought because of this saw. Glad I found this forum.

I didn't see any fuses anywhere on the saw. The documentation for the transformer shows an accessory kits for fuses though. And what the links look like.
https://www.alliedelec.com/m/d/e080d77cc65265fc0a39e8b46c6f87d9.pdf

 

[Asymptotic]

Although it might be a trick of the photograph I wonder if whoever replaced the transformer copied the connections from the original transformer without realising the replacement required strapping

Great catch. I don't see them either.

There are 3 fuses shown around T1 on the circuit diagram but I can't see any of them in the pictures. Perhaps they are on the door of the control box?

The BOM shows F1 through F3 as T2A, 5x20mm, and F4 & F5 (protecting compressor motor) as T10A, 5x20mm fuses. The highlighted areas look like specialty (fused, non-indicating) terminal blocks, although one on the right hand pair is unmarked, the other tagged F6, and neither of them appear to be wired to anything.

5x20 fused terminal blocks are great space savers, but (personal opinion alert) not well suited for transformer protection. 5x20 fuses tend to run at higher surface temperatures than, say, equivalent 10x38mm fuses, and having several of these terminal blocks in contact with one another makes for poor heat dissipation.

Another thing that catches my eye is 2A fuses for a 100VA transformer. I'm not particularly sanguine using one on the 120V secondary (2A fuse/0.83 FLA = 240%) let alone for the primary (if 240V, then 2A fuse/0.42A at full load; fuse rating is 480% of transformer rating). 2A fuses will prevent wiring from burning up, but do squat for transformer overload protection.

When space is at a premium, I'm happier seeing a transformer fitted with 10 x 38mm fuse holders on both primary and secondary, populated with fuses more closely matched to transformer VA rating.

 

[Tom.G]

In the new pictures (thanks) I can't see any strapping on the T1 transformer for 240 V operation (top row) or 120 V operation (bottom row).

The straps go over the barriers on the terminal strips and are hard to see, but do exist and are visible on an enlarged view of the image.

Another thing that catches my eye is 2A fuses for a 100VA transformer. I'm not particularly sanguine using one on the 120V secondary (2A fuse/0.83 FLA = 240%) let alone for the primary (if 240V, then 2A fuse/0.42A at full load; fuse rating is 480% of transformer rating). 2A fuses will prevent wiring from burning up, but do squat for transformer overload protection.

Those fuse ratings seem reasonable when you take into account the in-rush currents of the transformer and of the contactors/relays. Time Delay fuses at closer to rated current are an option but are seldom seen in practice.

If power is applied to the transformer when the AC line is near its peak in the same phase as when the power was removed, the core may go into saturation for the first half cycle, causing a brief, high in-rush current.
The same happens with the contactors, but even worse is the in-rush current until the armature pulls in and completes the magnetic circuit. The coil inrush current is 5 to 10 times the sealed current.
See page 3/50 of: http://www.klocknermoeller.com/klockner.moeller/klockner.moeller.pdf/sec_3.pdf

Control transformers are designed to handle these in-rush currents by using more Iron in the core to prevent saturation during momemtary overloads and larger wire sizes to decrease resistive losses. Due to this, they are a "stiff" supply with good load regulation and can typically be run at full rated power almost indefinitely.

It appears to me that the motor has been rebuilt or at least apart because some of the fins on the rotor are bent and almost all of them have been scuffed on the corners. There isn't any scuffing to the case and the bearings are tight. I am wondering if it was my setup that caused it or if it was already on its way out the door.

That's problably why they unloaded it!
The photo of the rotor indicates the fault occurred during a powered startup, otherwise the burn mark wouldn't be concentrated in one spot.
The photo of the burnt winding has what looks like a piece of metal sticking out at the fault location. This could well be the base cause of failure, perhaps a leftover from a previous rebuild. A rewind is due in any case.

EDIT: A closer look shows that "piece of metal' is probably a lead wire.

Still seems like a good deal.

Cheers,
Tom