Overmod I protest the unnecessary political slant of that drawing as provided, particularly the kokkinoerythrophobia implied by its orientation. Surely we are above preferring one color over another in our modern societal preferences! Simply rotating the drawing 90 degrees would address the implied privilege issue... although then the primacy of Western-centric reading/scanning preference comes into play. Perhaps using non-politically-charged wire descriptions, like 'hot' and 'ground' (terms chosen themselves to remove the taint associated with terms like 'positive' or 'negative' and their potentially-racist color implications) should have been used.
I protest the unnecessary political slant of that drawing as provided, particularly the kokkinoerythrophobia implied by its orientation. Surely we are above preferring one color over another in our modern societal preferences!
Simply rotating the drawing 90 degrees would address the implied privilege issue... although then the primacy of Western-centric reading/scanning preference comes into play.
Perhaps using non-politically-charged wire descriptions, like 'hot' and 'ground' (terms chosen themselves to remove the taint associated with terms like 'positive' or 'negative' and their potentially-racist color implications) should have been used.
Bill
"Never try to teach a pig to sing. It wastes your time and annoys the pig"
Removed at OP's request.
for the click impaired
Henry
COB Potomac & Northern
Shenandoah Valley
Here's a sketch of the wiring at the base of the DPDT center-off switch.
alfadawg01Does anyone see any problems with the wiring plan?
alfadawg01when I touch the probes to the same rail with an insulated rail joiner between the probes, the buzzer still sounds. Is that supposed to happen?
it explains the above.
alfadawg01This was a functioning layout with a DC power pack. I wired track power from the DC power pack and the PowerCab through a DPDT center-off toggle switch so I could use either one (but not both simultaneously!) to power the layout.
i still don't understand what damaged the PowerCab. i would suggest disconnecting the DC controller from the layout when connecting the PowerCab.
could you post a diagram of how the DPDT switch is wired to the DC PowerPack, PowerCab and layout
greg - Philadelphia & Reading / Reading
rrinker I see someone else watches The History Guy
Who?
I see someone else watches The History Guy
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
It's better to ask for forgiveness than permission And don't all great stories involve pirates?
Thanks, Henry, whatever works.
Didn't notice the OP used google photos because I could see it. I don't always see google photos, but that is another discussion. I pirated his photo
Randy,
So the way I've wired things, while probably being a bit of overkill, is not a problem?
You need to use a photo hosting service to post pics - on the main forum there is a sticky with instructions.
If there is a feeder to the rails from a bus, then an insulated joiner, then another feeder fromt he same bus, all on the same rail - you will get contnuity across the gap, because both sides are linked by the wire. That's not necessarily a problem, and Insulfrogs don;t really need gaps or insulated joiners on the frog rails anyway. Electrofrogs do, if there are any feeders past the frog (which there will be on all but the most trivial of track arrangements).
This wiring diagram may help:
I have insulated joiners at the frog ends of my turnouts on each rail of the through route and the diverging route. There are feeders near the point end of the turnout and beyond the insulated joiner. Is that easy to visualize? I can provide a sketch if it helps.
I set the meter for ohms and set the probes on either side of the joiner. Reading was 0.
Turnouts are code 100 Peco Insulfrog.
alfadawg01However, when I touch the probes to the same rail with an insulated rail joiner between the probes, the buzzer still sounds.
why is the insulated rail joiner there? what is it's purpose?
is there another gap on that rail?
The immediate thing I'd do is to switch to the ohm setting and make the same measurement. If the meter shows the equivalent of a short (like an L or -1 depending on meter type) then your "insulated" rail joiner may not be working as designed... if the number of ohms is finite, the joiner may be compromised in some way. Report the number you get when you measure.
edit-delete if I didn't open my mouth so much, I would think I was a lot smarter.
Bill,
What is your trackwork insulated from at that spot? Are you running feeders to both sections of track from a power bus? If it is insulated then you should NOT be seeing continuity between the two sections of rail.
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
I have conducted the first phase of testing by setting the multimeter to test conductivity and running it over every inch of track on the layout, all 24' or so of it. The buzzer was quiet so it appears there are no short circuits.
One question however. When I touch both probes to the same rail, the buzzer sounds, as expected. However, when I touch the probes to the same rail with an insulated rail joiner between the probes, the buzzer still sounds. Is that supposed to happen?
richhotrain alfadawg01 The PowerCab is finally on it's way back to NCE. The USPS screwed up and picked up the package two days late. Sigh... Nah, no screw up, that is standard USPS procedure. Rich
The PowerCab is finally on it's way back to NCE. The USPS screwed up and picked up the package two days late. Sigh...
Nah, no screw up, that is standard USPS procedure.
Rich
Of course.....the new normal. Silly me, why didn't I think of that?
alfadawg01 The PowerCab is finally on it's way back to NCE. The USPS screwed up and picked up the package two days late. Sigh...
Alton Junction
New surge protector ordered this morning: Tripp-Lite Isobar Ultrablok. I have been using one of these for my music studio gear for several years with satisfactory results.
Started using the multimeter to do continuity testing. I ran tests on all the freight cars that were on the layout at the time of the incident and all of them checked out ok, no short circuiting of the metal wheelsets. Progress....
Nothing will save you if the strke is on or near your house - even unplugged stuff can be damaged in that case. But cheap surge supressors can be worse than none - if only because they give a false sense of security.
The MOVs do degrade over tiem depending on the level of surge they see. Even if you never get a big enough hit to destroy it outright, they do degrade over time. The better ones will tell you to replace them every so many years, even if you've never taken a major hit. Some do have circuitry to induicate the effectiveness of the protection, or at least indicate that the protection has fallen below the rated value and it's time to get a new one.
For my test gear, I have a surge porotector and filter, not only does it have surge protection across all legs, it also has EMI filters to keep electrical noise out of the plugged in equipment. Overkill? Maybe, but they aren't any more expensive than a good quality surge protector, plus these have a remote on/off switch which I mounted in the corner of the bench so it is easily reachable while the base with the outlets sits in the back.
I had one of these for my layout 2 layouts ago, put the switch ina convenient position and mounted the base up under the benchwork - single switch (which has a pilot light in it) turned the whole layout on and off.
BigDaddyI thought surge suppressors "burned out" with surges. Am I wrong?
In practice, as noted the 'surge suppression' in the cheap devices is done with a single MOV, likely physically resembling a large disc capacitor. This is connected as a 'short' between the hot and neutral, or from a protected line to ground, and it works by promptly dropping resistance when subjected to overvoltage. Since many forms of spike that are lethal to tiny semiconductor architecture are of relatively short duration, the 'short' to any part of the AC waveform potential during the time the MOV is conducting is relatively brief also; when the voltage comes down, the MOV goes back to high resistance, and all is well.
The problem comes in when the surge has current as well as voltage behind it, like a nearby lightning strike (or some types of EMP). Now when the MOV conducts, a high transient current goes through it ... and while the resistance is small compared with impedance of the connected equipment, it is still large enough for P=I2R to rise up and bite. This likely causes permanent cumulative damage to a MOV even if it does not fail. I would frequently find the two sides of the 'disc' of a MOV completely blown off in a failure -- little matter to fix; you unsolder the legs and solder in a replacement. But until you do, the protection is, well, at a permanent very high resistance and no longer effective at surge suppression... and you may not have any warning the "protection" has not failed safe. [As a note: you can design surge protectors to 'fail safe' but this involves them ceasing to provide power to their outlet(s) permanently, without warning, and many consumers rise up in rage at discovering their $20 or more power strip is suddenly and forever 'no good'...]
A better class of surge protection would use something like Zener diodes, or some variety of gas tube, that conducts large currents to effective ground within a few nanoseconds of overvoltage rise time. And then just as quickly shuts off when the overvoltage goes back down. It is possible to design these to survive larger peak voltages and currents without potential (no pun intended) damage to connected equipment. In some cases it is necessary to provide 'charge storage' for the electrons transferred in a pulse event, where it is impossible to 'dump' them to an external conductor or ground that has a lower potential; this can be difficult to arrange in the necessary short time imposed by, say, electron-displacement EMP.
I thought surge suppressors "burned out" with surges. Am I wrong?
alfadawg01The surge protector that the PowerCab was plugged into is behaving odd.....the protection cuts in and out.
I recommend getting a better grade of surge/transient protection, and making sure you have a good path to dissipate or redirect a good amount of surge energy (this is what is measured in joules in the documentation) all the way through a dioded (and perhaps lightning-arrested) ground connection. Some DCC equipment is too expensive to risk not carefully protecting -- just as Warsteiner says 'life is too short to drink cheap beer'.
Tom and Rich,
The DPDT switch is on the list of things to test for anomolies. I may have switched from OFF to DCC at the time of the failure, but definately not from DC. On NCE's website a DPDT center off switch is the recommended method of having DC or DCC on a layout. Just need to check the electrical integrity of my switch and wiring.
Two discoveries have made life more interesting. The surge protector that the PowerCab was plugged into is behaving odd.....the protection cuts in and out. Replacement might be in order. I also found a turnout that was not fully closing in one direction. Something may have been knocked out of alignment during a track cleaning. The throwbar was hitting the end of a tie on a diverging track, preventing it from throwing completely. The offending tie has been trimmed and proper contact is being made again.
Never a dull moment....
gregcit's hard for me to imagine how a short can damage a PowerCab. how large a short is possible with the standard P114 (5240221) power supply, 1.8A
it occurs to me that that the PowerCab can be damaged if an active ~2A DC power supply somehow gets connected across the PowerCab output. the combined short circuit current will be ~3.8A flowing thru the PowerCab output
it's also conceivable that the PowerCab can be damaged, even when turned off, if a higher power DC supply is connected across the Power Cab outputs. The Powercab short circuit protection doesn't prevent excessive power from coming from the track.