I’m ready to install fuses on my O gauge layout Am I right to assume that they go on the bus lines A, B, C, & D, but not the common bus line (U)? on my ZW. I’m using 3 terminals for trains.
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@Don Baird posted:I’m ready to install fuses on my O gauge layout Am I right to assume that they go on the bus lines A, B, C, & D, but not the common bus line (U)? on my ZW. I’m using 3 terminals for trains.
Correct. You may also want to see basic circuit protection at "Circuit Protection for Toy Trains".
That's where I shared my protection on a very large layout.
I still don't understand the fascination with fused ZW outputs. The transient voltage spikes zip right through and around those, and when you're out of fuses, no more train play.
Fuses and TVS protection diodes perform two very different functions. I like Susan's idea of using PTC's in place of fuses, but you still need to add the 1500W 33.3V TVS at Digikey for transient voltage spikes.
Susan's diagrams are very helpful for an electronics novice. John, where would I add the TVS?
Thanks
Add the TVS at the track connection for each transformer output. It goes directly across the power like you're trying to short it out.
Where would I be able to buy some of these electronics parts?
Don, actually, installing a fuse in the common would provide better protection for the ancient PW Type Z/Zw transformer, as you can limit the current draw to 10 amps. Do note that all U terminals are connected internally, so you can use one as common for all circuits. Having said that, the terminals are riveted to a common internal buss, and over the decades these connections may have deteriorated.
I also recommend using breakers rather than fuses. The latter cost to much, as they'll blow on every derailment. In a recent thread GRJ has piinted to a source for magnetic breakers. I currentlyuse thermal breakers, which are slower and cheaper, but am considering whether to switch to the magnetics GRJ recommends..
@Trainfamily posted:Where would I be able to buy some of these electronics parts?
RJR, this string is very confusing to me, but your comment seems to be at my level. Let me tell you where I’m coming from
in a previous chain I posted questions about my Christmas trains - two trains circling the tree on two circles of fastrack powered by my ZW. One of the power lines and the carpet melted presumably because of my grand children’s derailments. I replaced the badly worn power lines with 16 gauge for the remainder of the season I also decided to add some precautions to the permanent layout I’m building using tubular track, my ZW, and and a 1032.
So, I decided some kind of fuses or circuit breaker. Your answer to my question was unexpected and simple if I understand it. Put a circuit breaker on the common bus - U on the ZW. I had assumed it would be a 10 amp breaker on terminals A, B, & D for the three trains and a lower amp breaker for C. Tell me if there’s anything right about that.
with the 1032 I am using variable power terminals U & B for the trolley. (U to the center rail). Fixed power from B & C powers some accessories on the trolley lines and is converted to DC for a timer relay to control the stops & starts on the trolley line.
where do the circuit breakers go?
How do you know if the TVS at one of the lock-ons or below at input to terminal strip does its job and absorbs the transient voltage spike? It protects the locomotive electronics but kills itself but is it obvious so you know when to replace?
@SteveMa posted:How do you know if the TVS...
They are not one-time devices, they are continuously clamping transients. A TVS usually fails shorted, so it will be very obvious if it fails.
A TVS has a very long life unless it's subjected to a spike that exceeds it's maximum rating. They're quite different than an MOV, those degrade with ever surge they absorb. FYI, the MOV is what is used in most "surge protection outlet strips".
Thanks. Getting close to the comfortable zone with your help
Don, I'll answer your last question first. Breakers and fuses should always be on the transformer outputs, so they protect everything downstream.
A fuse or breaker in the U circuit has one purpose, to protect the transformer. A postwar ZW shouldn't be subject to more than 10 amps. FYI, the ZW internal breaker is in the U circuit, but is very slow acting. It provides no protection if there is a short between any of the ABCorD outputs, which is possible.
A current of less than 10 amps can cause considerable heating on the layout. Breakers or fuses should also be put in each of the output circuits to protect the layout. They should have the lowest amp rating that will operate your trains, which is usually less than 10 amps. On my layout, I run 6 TIU channels. Some channels control areas where probably not more than 1 or occasionally 2 trains will be moving at once, such as yards. These get 5 amp breakers. Mainlines where I might have 3 locos running get 7.5 amps. But I do not turn smoke on.
No fuse or thermal breaker opens immediately upon the current being exceeded. There is a lag while the thermal elements heat up. By using smaller amperage breakers, they open sooner on a short. In another thread, Gunnrunner John mentioned certain magnetic breakers available from Digikey. Magnetic breakers should open as soon as the rating is exceeded. Electronic breakers, such as in the Lionel PH-180 Powerhouse, also open upon exceeding the rating. I am considering replacing my thermal breakers with magnetics, but have some higher priority matters to deal with.
FYI, I use Blue Sea marine push button breakers, available on-line from Defender Marine. They are in the $5-$6 range and have worked well.
Hope this helps.
RJR
Thanks RJR. I assume it would be the same for the 1032: a breaker for each post in use (U, B, & C).. It’s only running a trolley and some accessories. Low amp breakers?
I don't know what the wattage rating is for that transformer, but I'm sure less than 10 amps is required. For those old transformers: Take the wattage rating; multiply times 0.75; divide the result by the maximum voltage the transformer can put out. The result is the maximum continuous amperage. Ideally, use that as a maximum rating on the U; on the others, that or some lesser capacity depending on the level of protection you want to afford your wiring and devices.
RJR
The 1032 is a 75 watt transformer generating 115 volts. With U as the hot shoe the results are:
AU 5-16 volts variable
BU 0-11 volts variable. Others:
AB 5 volts fixed
BC 11 volts fixed
(C 16 volts ?)
I am using UB Variable to power trolley & BC for conversion to DC timer and to provide auxiliary power to accessories
Your formula: 75 (watts) x .75 = 56.25 divided by (16 or 155 volts) equals 3.5 or 0.4 continuous amperage. Can that possibly be correct?
And even if it is correct, what does that mean for U, B, & C?
Do I even need to worry when all that is connected is a cheap MTH trolley, three 153IRS and a few accessories (crossing signals, station lights)
The transformer has a built in breaker to protect itself.
@Don Baird posted:RJR
The 1032 is a 75 watt transformer generating 115 volts...
The transformer has a built in breaker to protect itself.
The 1032 internal breaker is rated to trip on A-U in 9-35 seconds into .2 ohms , if that will help you.
The breaker on the 1032 is to protect the transformer.
@Don Baird posted:(C 16 volts ?)
A-C is 16 volts fixed. "A" is common on the 1032 and has the breaker in it's feed(except in relation to B), C-U is 11-0 volts(yes, backwards), but like A-B, there is no breaker protection.
3.5 amps would be the max continuous amps, aggregate for the transformer. I don't know where you got the 155 or 0.4 figures. 115 volts is the input from the wall receptacle; it is not something generated by the transformer.
FYI, the 75% continuous rating was given by Lionel itself in its Model Railroading paperback back in the 50's/60s. Also, the breakers in those old postwar transformers were not particularly good. I will leave it to others to comment of the maximum continuous rating for modern transformers.
A handy gadget to have is a cheap AC ammeter. You can ascertain the draw of each device.
Googling, I dug out the section of the Greenberg repair manual covering the 1032, including the schematic. Quite frankly, I can't figure out which combination of terminals are protected by the internal breaker. I'd fuse or breaker all leads
The manual does say the internal breaker when new would open in 7-8 seconds on a dead A-C short, but aging will increase that duration. No mention of protection for other post combinations, such as A-B, B-C, etc. The manual does say that not more than 50 watts should be drawn continuously. This would equate to 0.67 rather than the 0.75 figure I used. But it also says to limit continuous amperage to 4-4.5 amps. If you have much older Lionel equipment, the Greenberg Repair & Operating Manual for Lionel Trains is a worthwhile investment.
Having said all this, in my younger days, back around 1950, I use a Type R (100 watts) to run two locos (#224 & #736), 2 022 switches, and a #97 coal elevator.
Rob, Manual says the breaker is 4 amps
@RJR posted:Quite frankly, I can't figure out which combination of terminals are protected by the internal breaker.
A-B and C-U are not protected by the internal breaker.
@RJR posted:Rob, Manual says the breaker is 4 amps
Manual says the breaker is set to carry 4 amps continuously, but will hold a slight overload when the transformer is cool.
How to test it though is a different procedure. The manual gives an acceptable time - 9-35 seconds into .2 ohms using A-U.
To me, 15 amps for 35 seconds is not acceptable, either from a standpoint of protecting the transformer or of protecting the layout.
This is a bench test, no train equipment was harmed in the testing or development of this procedure by Lionel engineers of the 1940's.
Nevertheless, not acceptable off the bench.
Rob is correct, here's a wiring diagram. Even the combinations protected don't get very good protection with the specs of that breaker.
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I agree GRJ. If it is acceptable for that breaker to take <35 seconds to open with a 15-amp load, how long would it take when the load slightly exceeds, say, 4.5 amps? I would fuse or breaker every connected terminal for 4 or 5 amps max.
I think TVS has been covered really well lately. 1500W 33.3V TVS at Digikey
So while we're on the subject of fuses and breakers, would anyone like to offer some specific product recommendations for panel mount ultra-fast inline manual reset circuit breakers, such as can be achieved with solid state protection devices in the 5 to 10 Amp range suitable for 10 to 20V AC?
Somewhere on the Forum are recent posts by Gunrunner John about push button reset magnetic breakers, reasonably priced.
@RJR posted:Somewhere on the Forum are recent posts by Gunrunner John about push button reset magnetic breakers, reasonably priced.
Thanks, RJR. A quick internet search of Magnetic breakers on OGR turned up these posted by John:
Sensata-Airpax R11-62-7.50A-B01CV-V 7.5A
Sensata-Airpax R11-2-5.00A-B06CV-V, 5A
Sensata-Airpax R11-2-10.0A-B06CV-V, 10A
https://www.onlinecomponents.c...00aobv-10090622.html
Are these what you're thinking about?
They are definitively less expensive than the PSX-AC and according to that other thread better at lower voltages.
For really fast action, the PSX-AC Circuit Breaker modules are probably the king. THe Airpax Snapak Magnetic Circuit Breakers are very good, but I can't seem to find the fast acting ones without the hydraulic delay anywhere, those are the model you'd like to have.
Here's the Sensata-Airpax Breaker Datasheet, so tantalizing close, yet seemingly unavailable. You used to be able to get the instant trip models from Digikey, but now they only stock the slow ones.
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That is them. I'll attach their catalog
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I see Steve found the ones I was looking for, those are the fast acting ones.
@gunrunnerjohn posted:I see Steve found the ones I was looking for, those are the fast acting ones.
I just read further into the post and subsequently edited the links before I saw you posted.
What I had before was Sensata / AIRPAX PP11-0-10.0A-OB-V
Which is the faster acting?
Steve, I think the push button variety is easier to mount in a panel. Problem is that if one looks into the catalog where it describes the numbering system, there are a huge number of variations, and no one can stock them all.
Over the years, several forumites have designed various electronic packages for train use, and they or others have packaged component kits which they sold. I wish someone would do that for an electronic breaker such as is found in the PH-180 transformer, the circuit for which has been posted on the forum.
The -0 models are the instant trip models.
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@gunrunnerjohn posted:The -0 models are the instant trip models.
John, Thanks very much for your help. I just ordered 12 of the -0 (instant trip) for the price of 3 PSX-ACs.
@RJR posted:Steve, I think the push button variety is easier to mount in a panel. Problem is that if one looks into the catalog where it describes the numbering system, there are a huge number of variations, and no one can stock them all.
Over the years, several forumites have designed various electronic packages for train use, and they or others have packaged component kits which they sold. I wish someone would do that for an electronic breaker such as is found in the PH-180 transformer, the circuit for which has been posted on the forum.
RJR according to their site there were 29 (push-button panel mount 10A breakers) in stock before my order, so there should be about 17 left. Get em while they're hot.
What site? What breaker number?
Dang it, I forgot to post the link:
