Waddlemarsh - somewhere southwest of London sometime before today

[Gwiwer]

The bridge girder sections are now complete and painted. Painting was with Woodland Scenics Slate Grey roughly mixed with Jo Sonjas Smoked Pearl and Titanium White.  Railmatch Rust was then dry-brushed onto and in places worked into the not-quite-dry “grey” colour. 
 

 

 

 

[Gwiwer]

Fate sometimes smiles.

 

After the last time I switched the power on and the CDU showed a short I expected to have to inspect the entire wiring for a problem.  Even on a relatively small layout that's a big ask with thirty-odd points, power feeds and auxiliaries.  The problem was on the point-motor side so at least I could eliminate the track and aux feeds.  

 

As and when I have had a moment I have been completing the few bits of outstanding wiring and fitted a new point motor where there wasn't one before.  But in doing so I found a motor - fully wired up but not connected to a point - hanging beneath the layout.  Why?  I may never know.  I don't remember leaving it that way nor do I remember having wired from that point back to its switch but there it was fully wired.  

 

But the motor had the telltale signs of a burnout - a dimple on the top of the housing suggesting excessive heat - and the movable bar wouldn't budge.  It's an occasional problem with surface-mounted motors even with a CDU because they are not quite as robust as their underfloor counterparts.  

 

Short version?  I had already fixed a new motor to the point in question and when wiring back to the switch it became apparent where this rogue motor belonged.  I wired the new motor to the switch and HEY!!!  

 

No short   Not even a buzz   No movement either but that's most likely to be an issue with wires having been poked too far into choc-blocks and secured on their sheaths not the bare ends.  But it's a positive step and at least I no longer expect to need hours of frustration checking every single wire and connection.  

 

Fate sometimes smiles.  

[Gwiwer]

Yard buddies

 

 

[St Enodoc]

3 hours ago, Gwiwer said:

Yard buddies

 

 

Can we see more of the JA please Rick? It looks rather nice in the deep blue livery.

[Gwiwer]

14 hours ago, St Enodoc said:

Can we see more of the JA please Rick? It looks rather nice in the deep blue livery.

Sure. Why not?  
 

 

 

[Gwiwer]

In other news can anyone explain why I get a short across the CDU output when I connect two point motors master-and-slave style?

 

They form a crossover and I need them to fire as a pair. 
 

I have two other sets of paired motors which work fine. All are wired according to the plan below. But what ever I try, including a complete rewire, every time I connect green to CDU (and hence power the circuit) I get a short. Remove the green and all other points work fine. 
 

Baffled

 

[Gwiwer]

Another session and I'm still none the wiser on the point-wiring conundrum. 

 

Everything works fine across 34 other points.  I thought maybe there was a short in the switch for the crossover points but ...... I take the green (common power) wire from the motors back to a choc-block joint and wire it into a circuit which works normally.  But with this wire added it shorts out.  Remove the wire and everything resets and works normally.  

 

The motors have been replaced, the wiring replaced and there is nothing touching anything it shouldn't.  

 

What's up, Doc?  

[5BarVT]

Sounds like you may have tried this already, but . . . 
The fault comes on when you add the green wire after everything else?

So,

what happens if you disconnect this pair of points completely (red and green) and reconnect in order from the green (common) end?

It might give a better idea of where the problem lies.

Paul.

[Gwiwer]

On 18/07/2021 at 15:59, 5BarVT said:

Sounds like you may have tried this already, but . . . 
The fault comes on when you add the green wire after everything else?

So,

what happens if you disconnect this pair of points completely (red and green) and reconnect in order from the green (common) end?

It might give a better idea of where the problem lies.

Paul.

All disconnected. 
 

Reconnect green only. Short. 
Connect green and black only. Short

Connect green and red only. Short

Connect green with red / black swapped. Short.

 

Replaced and rewired control switch. Short. 

All other points work fine provided this pair is not connected. 
 

Head scratched. Mystified. 

[Stubby47]

Can you run the green to another pair of motors that works? So not directly back to the CDU.

 

[5BarVT]

27 minutes ago, Gwiwer said:

Head scratched. Mystified. 

A very reasonable response!

[Gwiwer]

45 minutes ago, Stubby47 said:

Can you run the green to another pair of motors that works? So not directly back to the CDU.

 

Yes. Been there and did that earlier. Shorts either way. 

[Siberian Snooper]

If other motors are also showing a short when connected to the CDU, perhaps there's a fault with the CDU. Do the motors work without the CDU?

 

 

[Stubby47]

Silly question - have you connected the wires to the motor correctly, not crossed the common over the motor rather than from solenoid to solenoid on one side ?

 

Can you try only one of the pair of point motors at a time ?

 

As you've replaced the motors it's unlikely that two motors have an internal wiring problem, but it is possible.

 

Cue remembering John Noakes on the underground.  Engineer has a large crate full of bulbs, and connects the wire to the live rail. Bulbs all light up. 

"Why do you have all those bulbs?" asks John.

"If we only had one bulb, we wouldn't know if the bulb had failed or the power was off. With 12 bulbs, even if one or two fail, the rest will light up." 

"What happens if all 12 fail?"

"If you're that unlucky, you won't live much longer anyway..."

[5BarVT]

44 minutes ago, Stubby47 said:

Engineer has a large crate full of bulbs,

The egg box!  For some reason, I assumed that it was only six bulbs.

Paul.

[St Enodoc]

1 hour ago, 5BarVT said:

The egg box!  For some reason, I assumed that it was only six bulbs.

Paul.

On the Suvvern it was 6. Perhaps LT had more.

 

You connected the trailing wire to the running rail first, then sat the egg box on top of the juice rail.

 

Oh, and they were lamps not bulbs. When I went to the SR I was told that bulbs grow in the ground (and lights are panes of glass you can look through).

 

Past tense used - scroll down here:

 

 

Edited July 21, 2021 by St Enodoc

[Stubby47]

10 minutes ago, St Enodoc said:

Oh, and they were lamps not bulbs. When I went to the SR I was told that bulbs grow in the ground (and lights are panes of glass you can look through).

 

Best tell that to Mr Edison, poor man has got it wrong all these years...

 

"As every third-grader knows, Thomas Edison invented the electric lightbulb.

Or did he? It’s painful to cast aspersions on the reputation of one of America’s heroes, but Edison, who patented his bulb in 1879, merely improved on a design that British inventor Joseph Swan had patented 10 years earlier. Swan sued Edison for patent infringement, and the British courts ruled against Edison (as punishment, Edison had to make Swan a partner in his electric company). Even the U.S. Patent Office decided in 1883 that Edison’s patent was invalid, as it also duplicated the work of another American inventor.

As it happens, Swan and Edison worked from bulb designs that had been in use since the early 1800s. The general principle was, and still is, this: When electrical current flows through the bulb’s filament, the filament heats up and glows, which produces light. The inside of the bulb is a vacuum, hence oxygen-free, so the filament doesn’t get oxidized and the glow lasts a long time.

Swan used a carbonized paper filament, but the poor quality of the vacuum in the bulb caused the carbon to disintegrate rapidly, so the bulb glowed for just 13-and-a-half hours. Edison used a better vacuum pump, and after he and his posse of assistants had tested thousands of materials, he made a filament derived from bamboo that lasted up to 1,200 hours. Today’s incandescent bulbs, in which the filament is made of tungsten, last about 1,500 hours."

 

https://www.cio.com/article/2441341/thomas-edison--joseph-swan-and-the-real-deal-behind-the-light-bulb.html

[St Enodoc]

Just now, Stubby47 said:

 

Best tell that to Mr Edison, poor man has got it wrong all these years...

 

"As every third-grader knows, Thomas Edison invented the electric lightbulb.

Or did he? It’s painful to cast aspersions on the reputation of one of America’s heroes, but Edison, who patented his bulb in 1879, merely improved on a design that British inventor Joseph Swan had patented 10 years earlier. Swan sued Edison for patent infringement, and the British courts ruled against Edison (as punishment, Edison had to make Swan a partner in his electric company). Even the U.S. Patent Office decided in 1883 that Edison’s patent was invalid, as it also duplicated the work of another American inventor.

As it happens, Swan and Edison worked from bulb designs that had been in use since the early 1800s. The general principle was, and still is, this: When electrical current flows through the bulb’s filament, the filament heats up and glows, which produces light. The inside of the bulb is a vacuum, hence oxygen-free, so the filament doesn’t get oxidized and the glow lasts a long time.

Swan used a carbonized paper filament, but the poor quality of the vacuum in the bulb caused the carbon to disintegrate rapidly, so the bulb glowed for just 13-and-a-half hours. Edison used a better vacuum pump, and after he and his posse of assistants had tested thousands of materials, he made a filament derived from bamboo that lasted up to 1,200 hours. Today’s incandescent bulbs, in which the filament is made of tungsten, last about 1,500 hours."

 

https://www.cio.com/article/2441341/thomas-edison--joseph-swan-and-the-real-deal-behind-the-light-bulb.html

Ah, but Messrs Edison and Swan never worked on the Suvvern.

 

Anyway, in these parts they're not bulbs either - they're globes.

[Stubby47]

Oh, so you want the whole world to follow the abstract ramblings of a small provincial railway in the far corner of England and call bulbs 'lamps' , then immediately contradict that as one colony calls them 'globes'.

 

None of which helps Rick fix his errant short.

[5BarVT]

56 minutes ago, St Enodoc said:

Oh, and they were lamps not bulbs. When I went to the SR I was told that bulbs grow in the ground (and lights are panes of glass you can look through).

Not just Suvvern, I’m sure I have been chastised by railway plant people elsewhere after using said term.

Paul.

[St Enodoc]

6 minutes ago, 5BarVT said:

Not just Suvvern, I’m sure I have been chastised by railway plant people elsewhere after using said term.

Paul.

I thought the plant people would have preferred bulbs...

[Gwiwer]

1 hour ago, Stubby47 said:

None of which helps Rick fix his errant short.

Indeed not. Fascinating little aside though. 
 

I’ll have another look when it’s a bit cooler. Currently the sun is aiming directly at the railway-room windows (though is excluded by Phonecian blinds) thanks to a neighbour removing a large tree out the back yesterday. 

[Gwiwer]

4 hours ago, Siberian Snooper said:

If other motors are also showing a short when connected to the CDU, perhaps there's a fault with the CDU. Do the motors work without the CDU?

 

 

The CDU is fine.  

 

Mode = Faultfinding.  

 

I am in the process of disconnecting each green in turn where they enter and leave the choc-blocks.  Some runs are fine.  Others lead to a short.  I just need to trace where the problem is which may take some time with 24 switches controlling 27 individual point motors and the greens fanning out, as it were, from one at the CDU output to serve each motor in turn.  

 

Addressing another question - a perfectly reasonable one from @Stubby47 - the motors are all correctly wired.  On each motor black and red are wired to the two terminals on one side and the pair on the other side are greens with a spur from the main wire at one terminal across to the second.  

 

Patience, persistence and in this weather a good deal of perspiration are called for.  

[Gwiwer]

3 hours ago, St Enodoc said:

Oh, and they were lamps not bulbs.

When I first trained on the railway a "lamp" was a device attached to a signal or to the front / rear of a train and was also a hand-held item; all were used for illumination and/or signalling purposes.  

 

A "light" was a window but was never the windscreen.  Toplight, sidelight, doorlight etc.. 

 

A "bulb" was one part of a lamp which was (at that time) required in order to provide illumination though some were still oil-fuelled.   Bulbs also got planted in gardens and allotments when off duty.  

 

That was BR Eastern Region.  I used, and others also used, the same terminology around the various London terminals where I worked on ER, LMR, WR and SR.  

 

I now use grain of rice "bulbs" in signal "lamps" in order to provide "light" for illumination   

[Gwiwer]

And ........ 

 

Fault-finding by means of tracing back the green wires from the CDU and eliminating those which do not produce a short has been completed.  One short was traced to touching wires in a switch.  The wires were un-touched and that problem was solved.  But a short still existed so in fact I had at least two but as all green wires ultimately feed into one terminal it only showed as one.  

 

Next problem was traced back to a faulty switch; replace the switch and the short cleared.  

 

Finally the most head-scratching, befuddling and mystifying fault of all, the crossover motors, was traced to another defective switch.  I had rewired the original switch but with something amiss inside the housing that hadn't cleared the fault.  A new switch duly did so.  

 

Tonight I have a layout upon which all the points work as they should and which has the total of zero shorts.  At last.  And my supply of spare switches is now exhausted although there are two "white levers" (spares in signalling terms) on the panel which are not connected to anything.  They are also spare switches placed to fill the frame and which can be brought into use if any additional pointwork is added in the future.  

 

The next job is to wire up the signals but these must await the arrival of a voltage regulator.  I need to be certain that the 12V output is stepped down to 9V as Dapol has decided 12V is too much despite their original assertion that the signal motors were designed and built for 12V and could take up to 16V.  They don't; many users myself included have found to their cost that they burn out if 12V is offered.  

 

 

Edited July 24, 2021 by Gwiwer