LGB 21382 Streetcar - excessive current drawn..

PhilP

PhilP

G Scale, 7/8th's, Electronics
TRADER
Country flag
I have a (very 'new' looking) 2003 vintage Streetcar here..

When you run it at medium, or higher, speed it will keep cutting-out and then starting off again..

On analogue rolling road, it will draw in excess of 3Amps when running at a reasonable pace. This seems to cause the decoder/electronics to keep 'crowbarring' and cutting-out.
I think this may be (obscurely) a lubrication problem.. If I use a DVM to check continuity down the wheels and skates one side of the loco, I tend NOT to get continuity. - In my book, as all the axles have the carbon-brush pickups, then every wheel and skate down one side should be connected together.

There seems to be a fair amount of 'oil' (is this from the grease breaking-down over the years?) coating the brush-holders, contact strips for the skates, and the 'wire-rod' which relies on pressure from the cover to hold everything in contact.
I will try to 'de-grease' the electrical pickup-chain within the motor-blocks for a start..

Second problem:
Has anyone ever managed to get into the bottom of one of these units??
I have removed all the visible screws (including those under the frames at either end) and applied a more-than normal amount of force to try to part the black chassis from the body. No luck.

Cheers,
PhilP.
 
Possibly been over lubricated?

I brought an LGB loco where this had been done and the motor started to draw too much current and trip my controller.

The motor was replaced.

You might be able to clean up the Buler motor if you can access it?

I'm not familiar with the LGB Streetcar, so I can't help with dismantling....
 
Don't apply power again and you may get away with it.

I've worked on two of these, both for the same mate.

On one I let the magic smoke out of the decoder, investigation showed one of the motors contaminated with lubricant and drawing about 1.5A on no load. As he wanted sound I opted to replace all the electronics with a sound decoder. That's another story but fine in principle.

The other decoder also failed but this was down to one of the bridge diodes going short circuit for no reason, the tram hadn't run ever for more than a few minutes, and the blown decoder supplied the spare diode for the repair.

Getting into these isn't simple. If you P.M. me with a phone number I'll give you a call.
 
Neil:
I think the over lubrication extends to the pickups et al..
Lack of continuity down the side of the loco leads me to think this.. ??

Mike:
I will have another look, but this is the larger 'bogie' Streetcar, not one of the smaller 'Tram' style units.

Thanks guys..
PhilP.
 
I have just realised that this is a USA streetcar. I have just finished reassembling one after fitting a XLS decoder. Access first from the top, remove the ventilators & then undo the screws underneath. The roof will then come off . Then work your way down, catching the doors as they remove themselves.
The bottom can be removed once the roof lighting has been disconnected & the decoder is in the "box" at the bottom.
Getting it apart is the easy bit. You now have to put it back together.
 
dutchelm said:
I have just realised that this is a USA streetcar. I have just finished reassembling one after fitting a XLS decoder. Access first from the top, remove the ventilators & then undo the screws underneath. The roof will then come off . Then work your way down, catching the doors as they remove themselves.
The bottom can be removed once the roof lighting has been disconnected & the decoder is in the "box" at the bottom.
Getting it apart is the easy bit. You now have to put it back together.
Click to expand...
??? :o ;) ;)

Yes, I have realised that once I get to the door/step area, and convert it to a kit of parts, reassembly may be 'interesting'!

Would need to get right down to the bottom to get the bogie-units off, so might be a better bet to work my way 'up' the bogie-unit to the motor??
I am still hopeful that the main problem is that the electrical continuity of the connection arrangement between brush-holders and skates. - From the oil contamination.
I might try a plastic 'shim' in the bottom of the motor block to increase the pressure on the 'wire' which links these items together.. Must admit, I had hoped to get-at the motor-block connectors to see how much current each motor was pulling..
 
Tricky indeed, one thing to watch out for is the use of rather similar screws of differing lengths. These really need to go back in the right locations.
After a few attempts the hard way I found it possible to remove the ends without the doors falling out. However the floor underneath them still needs to be removed to ensure wires aren't trapped when reassembling.
 
Once you get the roofs off, inner & outer, you can then get down inside to unscrew the bogie retaining screws. Depending on the length of the cable you may be able drop the bogies out.
When new some of these trams were not picking up power properly & needed "adjustment" of the bits of wire inside. This should not account for high currents however.
 
This might help:

https://www.champex-linden.de/download_lgb_explosionszeichnungen/21382p-1.pdf
 
Thanks guys..

Looking like oil contamination of the motors, or a faulty decoder.. I have had the Halfords engine cleaner round the pickups etc..
Still drawing 2amps at a brisk crawl, and shutting down a 3.5amp current-limited supply at 15V (analogue) to the track.

I will clear the decks, and convert it into a kit of parts next!!
:o ::) ;) :D :D
 
dutchelm said:
When new some of these trams were not picking up power properly & needed "adjustment" of the bits of wire inside.
Click to expand...
I also noticed that and I found these short wheelbase motor blocks the most awkward of all to get all wheels and skates picking up properly.
 
The New York trams were the worst. Mine only picked up on two wheels. Chinese quality control at its best. I've just had a New Orleans one apart & it is built the opposite way round. When reassembled it went backwards.

A tip for getting the vents off. Prise them outwards.
Don't think you can get away with bottom entry as the roof still has to come off to reconnect the lights.
 
Latest update:
I have removed the outer, and inner, roofs to get access to the bogie mounting screws..

Push/prise the roof vents outwards to get to the outer-roof screws..

Inner-roof screws: the screws to the rear of each door are considerably longer than the others. - Note for re-assembly.
you need to remove the push-on lighting connections from each end of the roof lighting bar, and the two connections bringing power up from the rear of the car.

Had a motor-block disconnected, and if I go directly onto the motor (outer) pins, the motor runs nicely at about 0.3Amps.

If I use a pair of female spade (lucar) connectors to bridge the pickup-pins to the motor-pins, and supply power via the skates, this bogie now runs as above, at about 0.3Amps..
I can move the croc-clip to a wheel on one side, and it will still run. - the other wheel on the same side has no continuity..
Putting the clip back on the skate, and trying the same procedure on the other side, neither wheel / brush combination pass power.

This seems to suggest my initial diagnosis of problems with power pickup is correct.
The brush-holder tubes seem to be a little 'dull' in colour (oxidisation perhaps) and the wire/rod which runs along the motor-block to provide continuity is/was very oily.. I am tempted to bend a few slight 'kinks' into these wires to see if I can improve continuity.. Failing this, it will be a case of soldering a 'jumper' from each brush-holder, and the shim the skate passes current through to this wire.

I suppose there could still be a problem with the decoder itself, but need to sort power pickup as a first measure..

Any 'hints and wrinkles' on tweaking these motor-blocks please?

PhilP
 
Just a thought..
Although this car has had little use, it has been run..
How long should the carbon ends of the brushes be? - I do not seem to get continuity from the wheel to the case of the brush-holder. Even if I clean the rear face of the wheel.

It is not possible to completely remove the bogie from the Streetcar, as the wire passes under a moulded 'bridge' section on top of the motor-block.. I have not found a way to release this as yet. - May be a screw from inside the housing??
 
If you are putting in several amps there must be some kind of continuity. Sounds like the decoder or sound unit. Have you tried applying volts with the motors disconnected.
 
PhilP said:
It is not possible to completely remove the bogie from the Streetcar, as the wire passes under a moulded 'bridge' section on top of the motor-block.. I have not found a way to release this as yet. - May be a screw from inside the housing??
Click to expand...

Prise it upwards, the "bridge" is a very tight push fit.
 
Yes..
One motor disconnected, and now managed to get continuity through both axles and skates on that bogie.. Had to build-up a little solder on the outside of the brush-holders on one axle to get contact with the rod/wire in the block.
Now need to work on the other block with similar problems.. Skates and wheels one side have continuity, skate other side now passes current, but nothing through the other wheels.

Am now done to about 1.4Amps at 15V analogue, so it is the resistance of the current-pickup through the blocks which is causing the large current draw.
 
Thanks Neil.. Will be a little more 'forceful' with block No.2!

Counter-intuitive from Ohms law, but I suppose the decoder is trying to 'amplify' the track-voltage it is getting to drive the motor at the required speed? Hence pulling excessive current.

Looks like I could have persevered in working from the bottom-end, but at least I know the motors aren't full of oil..
 
Now I am confused!!  ??? :o

Never seen one of these before!!??

DSC00265-1.jpg

Give me a clue someone, please?
??? ;)
 
Motor-block has two 3-way connectors to pcb's into the block..
I was going to do the same as the first one, but will have to just 'attack' it from the bottom, and sort the continuity problems.
 
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