hi everybody.
i have just wired up the bus as it will be dcc  eventually,dc at the moment.when i finished i found i had a short.i know  i should have checked as i went but it worked ok before when it was  partially wired.i have since disconnected all droppers but as i start to  replace the droppers the first one connected causes a short.i have  checked the bus on it's own with nothing connected and that is ok,also  checked that insulated joiners are in the right place.the only thing  that is different is that i have a double crossover with it's own mini  bus but this is disconnected on the power wires.i have also tried the  points at each end of the crossovers in both positions in case this made  any difference.it didn't
does anybody have any ideas please as it's close to pulling out hair time.

ps.to mods,if this is in the wrong place please feel free to move it.it didn't seem right for the dcc section.                                                                     

Hi Alan,

Shorts can be frustrating. The good news is that you are taking the correct approach ( slow and painful as it might be).
You say that you get a short as soon as you connect the first droppers -  can you take a photo or describe exactly what you are doing?

[user=1033]spurno[/user] wrote:

hi everybody.
i have just wired up the bus as it will be dcc eventually,dc at the moment.when i finished i found i had a short.i know i should have checked as i went but it worked ok before when it was partially wired.i have since disconnected all droppers  **** but as i start to replace the droppers the first one connected causes a short.i have checked the bus on it's own with nothing connected and that is ok,also checked that insulated joiners are in the right place.the only thing that is different is that i have a double crossover with it's own mini bus but this is disconnected on the power wires.i have also tried the points at each end of the crossovers in both positions in case this made any difference.it didn't
does anybody have any ideas please as it's close to pulling out hair time.

ps.to mods,if this is in the wrong place please feel free to move it.it didn't seem right for the dcc section.

Checking - ****  you had disconnected ALL droppers? This means the track has NO wires at all connected to any part of the bus?  So connecting one dropper back then cannot cause a short.

If you can do a track plan showing where you have put insulated joins & where you had connected droppers, this will help us.

 

Edit - please indicate the type of points - Insul or Electrofrog  and do you have frog switching?

It could be those crossovers Alan - are you sure they're insulated at the "toe" ends ?

First, while you've still got some hair, check and double check that you haven't left anything metal lying on the tracks anywhere - a screwdriver, pliers etc. etc.  Daft as it sounds, it's been done before …….often !!!  Even a track pin stuck in the switch rails or frog could do it ……………:roll::roll:

If it's nothing physical, then it's got to be the wiring.  A good idea is to get a wagon and put a red mark on one side and a black on the other.  Then, put it on the track with the red side above a known positive rail.  Without removing it from the track, run it along every piece of track you've laid.  The "red" side should always be on the positive rail and the black on the negative.  I wouldn't mind betting, at some point, the two will try to swap causing the short (and I'd guess it's somewwhere on those crossovers …………;-)).

By absolute coincidence, Trevor (xdford) has posted excactly the above "wagon" idea in his "Hints and Tips" thread this morning.  At least I assume it's by coincidence ………………..whatever, it's credited to someone else ………….:roll::roll:

Hi Alan

Do you have access to a multimeter. set it to continuiity (often with a musical note), if not a bulb connected to a battery.
connecting the leads togther should complete the circuit giving either a buzz, or bulb will light up.
Now with all the droppers disconnected and no power to the layout (disconnect the power feeds) test the layout, first of all at the power feeds, then at the track. You should no get a completed circuit. If you do and have checked the track is clear, try changing the points, one at a time.
If the first test was clear, start making the connections one at a time, testing as you go - the buzzer feature is really helpful for this.

hth

Paul

[user=540]gdaysydney[/user] wrote:

Hi Alan,

Shorts can be frustrating. The good news is that you are taking the correct approach ( slow and painful as it might be).
You say that you get a short as soon as you connect the first droppers -  can you take a photo or describe exactly what you are doing?

hi Dave
a photo's a good idea but i don't think  the underside of my layout would help you much.:lol:

Checking - ****  you had disconnected ALL droppers? This means the track has NO wires at all connected to any part of the bus?  So connecting one dropper back then cannot cause a short.

If you can do a track plan showing where you have put insulated joins & where you had connected droppers, this will help us.

 

Edit - please indicate the type of points - Insul or Electrofrog  and do you have frog switching?

hi Sol
what i should have said was all droppers disconnected but power from controller to bus still connected.points are electrofrog and no frog switching.


  It could be those crossovers Alan - are you sure they're insulated at the "toe" ends ?

First, while you've still got some hair, check and double check that you  haven't left anything metal lying on the tracks anywhere - a  screwdriver, pliers etc. etc.  Daft as it sounds, it's been done before  …….often !!!  Even a track pin stuck in the switch rails or frog  could do it ……………:roll::roll:

If it's nothing physical, then it's got to be the wiring.  A good idea  is to get a wagon and put a red mark on one side and a black on the  other.  Then, put it on the track with the red side above a known  positive rail.  Without removing it from the track, run it along every  piece of track you've laid.  The "red" side should always be on the  positive rail and the black on the negative.  I wouldn't mind betting,  at some point, the two will try to swap causing the short (and I'd guess  it's somewwhere on those crossovers …………;-)).

hi Peter
part of the problem was the crossovers.on one of them i had the power wires reversed.what a dipstick i felt.


Hi Alan

Do you have access to a multimeter. set it to continuiity (often with a musical note), if not a bulb connected to a battery.
connecting the leads togther should complete the circuit giving either a buzz, or bulb will light up.
Now with all the droppers disconnected and no power to the layout  (disconnect the power feeds) test the layout, first of all at the power  feeds, then at the track. You should no get a completed circuit. If you  do and have checked the track is clear, try changing the points, one at a  time.
If the first test was clear, start making the connections one at a time,  testing as you go - the buzzer feature is really helpful for this.

hth

Paul

hi Paul

yes the multimeter has earn't it's corn today.

anyway guys i will start again tomorrow and keep you informed.

hi guys

"eureka".have now sorted problem,i found a metal joiner where an insulated one should be and i checked.must go to specsavers.this is the second time i've had the same problem so i should take more care.thanks to you all for taking the time to offer solutions.much appreciated.

Hooray !!! :doublethumb:doublethumb:doublethumb

It's always a huge relief when you find the problem Alan - regardless of who's fault it was in the first place. :lol::lol::lol::lol:

The problem with electricity is you can't see it !!  With water, you'd see where it was leaking but with electrics, they just bite you from nowhere …………:roll::roll:

Anyway, I'm delighted you've solved it - onwards and upwards eh ………:cheers

Cooking by gas now - err maybe the wrong comment when shorts are involved

Congrats

Paul