Wiring short

Carl L
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Re: Wiring short

#11

Post by Carl L » Wed May 13, 2020 8:22 pm

Whether this helps or not, but I've just tried disconnecting the pm, i.e C, D, E @ F wires (only leaving A & B to the switch; moving the switch by hand the short still occurs.

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Brian
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Re: Wiring short

#12

Post by Brian » Wed May 13, 2020 8:35 pm

Thanks for the drawing.
I do wonder if the the problem is with the LED wiring? Have you completely disconnected them all? By that I mean you may like to try and disconnect the two feeds to all the LEDs that are on D & E of each Seep. Take them all off - those recently connected and possibly may have caused the short and see if the short has then gone.
Seep C is the return from both coils and should not be in connection with any track feed wires.
The drawing doesn't show it but I assume the CDU is powered by something separate, like for example a 16 volt AC power source.

One other thing Ive just thought of is how your LED and frog wires are connected, When I suggested removing the wire from F and test was the LED and frog still joined? I would ensure the LED wire and the actual frog wire are physically separated when testing

Obviously remote fault finding has to be by best quess and assumptions :D
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Carl L
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Re: Wiring short

#13

Post by Carl L » Sat May 16, 2020 2:57 pm

Apologies for the few days break from this thread, work interfered.

Image

With all the LED's removed I have finally found the short, but have no idea why. It is the feed on the short section of track between the two points.

I have checked the feed, to the extent of deliberately wiring it wrongly, i.e. +ve to -ve and vice versa.

With the feed correctly wired, irrespective of which way the top electrofrog point is thrown as soon as the bottom insulfrog point is thrown to to run to the left the short occurs. With the feed disconnect there is no short. There are no other feeds in the yard that are connected.

I'm really struggling to work this one out.

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Brian
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Re: Wiring short

#14

Post by Brian » Sat May 16, 2020 3:50 pm

Hi
When the lower Insulated frog point is set straight there is no short as the right hand (Outer) rail leading up to the Electrofrog point is electrically not connected to the lower line
When the Insulated frog point is set to the left (Turnout) that right hand rail becomes live and its meeting a rail of opposite polarity via the Electrofrog points outer stock rail.
There can, as far as I can see be only two reasons for this... The lower track is wired in reverse to the upper track _ Check that the outside rails are to the same feed for upper and lower tracks or the insulated frog point has a fault with its frog wiring underneath the point.
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Rog (RJ)
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Re: Wiring short

#15

Post by Rog (RJ) » Sat May 16, 2020 3:58 pm

Try fitting an Insulated Rail Joiner where shown

Image

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Brian
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Re: Wiring short

#16

Post by Brian » Sat May 16, 2020 4:09 pm

While an IRJ will prevent the problem, as soon as a loco bridges the IRJ a short will return.

I've enlarged the image and I think I can see four rail feeds as shown. Check these are to the correct bus pair feed wires.

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Re: Wiring short

#17

Post by Carl L » Sat May 16, 2020 4:28 pm

The only two feeds connected are ones on the left, between the two points, the two on the left are not connected.

I deliberately reversed the two feed wires on that short track section and got an immediate short, so I believe that they are wired correctly. With the insulfrog set straight, when the electrofrog is set for the turnout there is no short. Do this not prove it is wired correctly? It is only when the insulfrog is thrown the short occurs.

Rog - when the short first surfaced I had an insulated joiner where you indicated. It made no difference, so as it wasn't really needed I removed it.

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Brian
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Re: Wiring short

#18

Post by Brian » Sat May 16, 2020 4:58 pm

Are you 100% sure the rail feeds are correct? Only if so then I would look at the Insulated frog points underside. Where the two bare wires link across to the Vee rails.

No, you're not correct re "With the insulfrog set straight, when the electrofrog is set for the turnout there is no short. Do this not prove it is wired correctly? It is only when the insulfrog is thrown the short occurs"
Power flows all the time along the right hand rail stock rail of the Electrofrog down the rail of the cross-over piece track and onto the open switch rail of the Insulated frog point. It is when the insulated frog point is moved over to the turnout position that its switch rail closes onto the right hand stock rail connecting a positive rail to a negative one = Short circuit. This is why I believe either there is a reversed rail feed somewhere. Or the Insulated frog is defective underneath. See drawing I've attached.

Just to check, you're not using the Seeps change-over contacts on the Insulated frog point for any rail feeding? This should only be used for LED indications if required.

Example of how polarity on one section causes a short when lower point moves over....
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Re: Wiring short

#19

Post by Carl L » Sun May 17, 2020 4:26 pm

Thank you, l've got that now.

I have rewired the feeds on the section of track and checked it back to the DCC wire bus to make sure it's correctly wired, which it is. I'm not using the Seeps change-over contacts on the Insulated frog point for any rail feeding. As all the LED's have been removed their not even powering them.

I have lifted the point and this is the underneath. Both the bare wires across the Vee seem secure.

Image

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Brian
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Re: Wiring short

#20

Post by Brian » Sun May 17, 2020 5:09 pm

Well done for persevering. Point looks OK. Is there still a short with the point removed?
I would if all is clear and with the point still removed, wire a temporary link from the lower track (where the point has been removed from) to the crossover piece of track outer rail and see if the short appears. This will prove that one feed somewhere is crossed over or not.

Like this..

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