Spreewald slows and smoke unit overheats

[mike perozzi]

Before I tear into the engine I need some advice. I recently noticed my Spreewald would intermitently slow down and at the same time would begin bellowing huge amounts of smoke. As if the smoke generator suddenly begins robbing the motor of power. The smoke stack has in fact melted somewhat. Any advice on what to look for?

 

[Greg Elmassian]

Yes, replacement parts!

Could you give more information like: is it running on DC only? Has it been modified?

Sure sounds like a shorted coil in the smoke unit.

You are not trying to run it with the smoke on and no fluid I assume, since it bellows a lot of smoke.

Greg

 

[mike perozzi]

Yes, replacement parts!

Could you give more information like: is it running on DC only? Has it been modified?

Sure sounds like a shorted coil in the smoke unit.

You are not trying to run it with the smoke on and no fluid I assume, since it bellows a lot of smoke.

Greg

Thanks for the reply greg. It is not been modified. The smoke unit in it is a sleuth 5 volt. When I purchased it used it looked like the stack was somewhat tilted like it had gotten hot before. I replaced the smoke generator with the sleuth 5 volt and it did pretty good for a while and now it's overheating. I run it on a dc. It seems like the smokestack is robbing the motors of electric. When the smoke starts to get real thick the engine slows down like most of the electricity is going straight to the smoke stack. I think I'm just going to disconnect the smokestack for a while. I'm wondering if there's a resistor somewhere in that circuitry that may have gone bad.

 

[Greg Elmassian]

try measuring the voltage to the stack, perhaps the regulator is blown and giving full track voltage to your 5v unit.

Greg

 

[mike perozzi]

Will do, and I'll get back to you later.

 

[mike perozzi]

Will do, and I'll get back to you later.

Ok, I measured some voltages simultaneously from the supply to the track and at the same time to the smoke generator. First I set up a stationary set up with the engine and smoke stack installed. The tube inside the stack was glowing red at 7.0V to the track. Eventually the insulation on one the the power supply wires smoked and melted (see pic) I removed the smoke gen from the stack and compared readings (left meter reads smoke stack voltage and right meter reads trans former voltage...see pics). once the smoke stack was removed the engine was able to accelerate more easily and seemed to operate in a smoother fashion, responding to the throttle . Thanks in advance for any advice.

 

[Greg Elmassian]

yeah, the resistance of the smoke units is so low, that just another volt or 2 will draw way too much current.

I'm guessing your transformer is only an amp or so, therefore it is natural that the smoke unit was drawing too much current for it to maintain voltage (you could give the transformer specifications)

So, the seuth smoke unit is rated 5 volts, but LGB usually runs 6... 7.5 volts is clearly too much..

Maybe Dan Pierce will jump in and give some wisdom, but I would replace the regulator.

There are no "brains" or regulator in the unit... it's a coil of wire boiling away fluid.

Greg

 

[mike perozzi]

I never had this loco apart. I'm wondering if it's in a board , is the regulator something that can be removed and replaced or do I just toss the whole board. The transformer is 20vdc, 60VA. Thanks again Greg!

 

[Greg Elmassian]

yeah, well should be north of one amp, so maybe your transformer is weak. It would not be an MRC 6200 would it?

I think the regulator is on the main board... unfortunately.

Something is definitely amiss...

Greg

 

[PhilP]

As Greg says, there is very little 'intelligence' in this loco, unless it has been fitted with a decoder at some point.

What colour are the wires to your smoke unit? - I wonder if it has been swapped at sometime in the past?

The LGB '5V' smoke unit should have white and black wires.

PhilP

 

[Greg Elmassian]

yeah, the 5v unit is the lowest voltage unit, I believe there are 5v, 18v and 24v (these are nominal voltage) units.

So the chance he has the wrong one is probably slight. (the 18v and 24v ones would pretty much ignore 7 volts ha ha)

Greg

 

[mike perozzi]

The wires coming out of the engine that are wired to the smoke generator are black and white one being black one being white

 

[mike perozzi]

You may have to use your imagination a little for the pics. The very thin white and black wires go to the smoke unit. The smaller board is the switch and the larger is for the "main board". As far as I can tell I do not see any "hot spots" in the boards. No signs of any type of damage in the circuitry. The only thing interesting to me is some slight discoloration, maybe corrosion, where the smoke unit wires connect at the switch. Any comments?

 

[dunnyrail]

Noting that ‘I replaced the smoke generator with the sleuth 5 volt’ has anyone any idea if that is the correct voltage smoke unit for an LGB loco? Yes there are plenty of electrics on the board but do they reduce the voltage to the 5v value or does an original LGB one run on a higher voltage? All the issues to me suggest to high a voltage to the Sueuth unit.

 

[Greg Elmassian]

It does regulate to a degree, but the voltage seems high. The regulator is definitely doing something, just not well it seems.

Greg

 

[Paul M]

The regulator is definitely doing something, just not well it seems.

Just like the regulators of pur water, gas and electricity suppliers

 

[mike perozzi]

Any idea what part of the board is the regulator?

 

[Dan]

I think the issue is this engine should have the 18 volt unit (yellow/brown wires). The circuit board looks like the very old one. It is true that LGB did put 6 volts to these units and the rating is 4-6 volts for the '5 volt' version. I have seen these run up to 6.8 volts. Also note the 2074 D/94 on the board where the 2074 is the LGB engine part number, D is Daampf German for smoke and 94 is the year 1994. This tells me this a very old board and would be 18 volt lights and smoke. Are the bulbs slightly orange and screw in to sockets? this indicates 18 volts for the bulbs.

 

[mike perozzi]

No, they are clear with 2 wires coming out.

 

[mike perozzi]

I wonder if this would be a good replacement board? Main Circuit Board, old version, LGB 20740-E028