short circuit in 55080 Reverse loop module.

G

Gorsebank

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I have a reverse loop module connected to my layout which until last evening worked fine.

When I started running this morning I had a dead short across the track as soon as the first loco of the day entered the section controlled by the 55080. The fault remained evan after a full restart without any locos on track.

After a series of illiminations i found that the 55080 was the cause of the short circuit. after pulling the unit apart and tapping the relay the fault cleared and it is now working correctly again. It is as if one of the two change over contacts in the relay stuck whilst the second changed thus causing the short.
Is this a known fault ?

I am aware of the revised LGB/Massoth unit which works without causing a momentary short but I would need to make a lot of changes to incorporate the newer unit and since the reverse loop unit is only triggered on rare occassions I dont want to go to the trouble of changing.
 
Not had this problem with mine?

I didn't realise that there is a relay inside the unit.

If you are capable, then it is probably worth replacing the relay....
 
Gorsebank said:
After a series of illiminations i found that the 55080 was the cause of the short circuit. after pulling the unit apart and tapping the relay the fault cleared and it is now working correctly again. It is as if one of the two change over contacts in the relay stuck whilst the second changed thus causing the short.
Is this a known fault ?
Click to expand...
I don't know about this particular unit but relay sticking in general isn't uncommon. You suggest one of the contacts changed, this removes suspicion from all but the relay itself. Provided you have adequate short circuit protection in your power supply I suggest ignoring the fault unless it repeats itself with irritating frequency, in which case just replace the relay. An internet search should reveal an inexpensive source.
 
I sometimes find relay circuits 'stick' (or partially make).. A 'tap' with a blunt instrument causes the relay to go fully over.
I have had this with polarity reversing boards I make for USA trains and Aristo stock. - My Digitrax does not give out as much voltage as MTS / Massoth.
I normally find once the relay has fired a couple of times, it will then work faultlessly.

If this is a 'one-off' then ignore it for now. - Your equipment obviously protected itself. It might be the cold as well??
If it becomes a common occurrence, then by all means swap the relay.
 
Thank you gentlemen.

The relay would be a messy one to change, it is mounted on a daughter board soldered to the mother board at rightangles.

It is an old 55080 bought second hand quit a while ago and has been in situ in my heated workshop for a year or so. this weekend was the first time it has been used other than on test when i first installed it.
I will see how it goes.
 
Ah, probably a bit sticky, and everything needed a kick to get going.. possibly worth forcing it to change-over a few times to get things moving again.
I would be bit stiff if I had not moved for a year or so!:D
 
Open the box up and clean the contacts use GIN (yes I said gin) or iso propollene switch cleaner. Alyn
 
Thanks for the suggestion Alyn.
The relay iis a PC mount version and is a sealed block and so replacing it would be the only solution.
Gave it a few test runs tonight and it worked fine.
Fingers crossed.
 
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