Post war ZW transformer circuit breaker pops after 5 - 10 minutes of running 3 trains simultaneously; what's up?

I use the outer handles to run trains ("A" and "D").
I use one inner handle to power switch tracks and the other inner handle to power uncoupling tracks.
That way I can tune the voltage differently for them.

bmoran4 posted:

carsntrains posted:

So Lionel says a ZW of any type can run 4 trains with no problems.   What baffles me is if they can.  Why are many here only running two trains per ZW?? 

Those using ZWs are likely to be running in conventional mode with high current pullmor motors and incandescent lamps. A single train with dual motors and a long string of passenger cars full of lamps could easily pull almost triple digit watts. Additionally, while the ZW has 4 throttles, only 2 have whistle and direction controls, and thus the other two "throttles" are relegated to power some accessories.

How is that running circles around a CW-80 that I know will run 3 trains on one transformer for as long as you want them to run?   If it takes 2 ZWs to run 4 trains, or 5 ZWs  to run 10 trains, what advantage does it have over 4 or 5 CW80s running ONE train each? Or even 4 or 5 CW40s running 4 or 5 trains?   In 1954, 1923, or 2017 it just aint making sense to me??   Or that Z4000 or whatever it is.

Remember, transformers are rated on watts, not "how many trains" they run. A ZW is rated at 275 watts, the CW-80 only 80 watts. A CW-80 may be hard pressed to run that elegant dual pullmor motor loco with that long string of passenger cars. With modern can motors, command systems, and low power lighting, you could get away with using only one throttle set to 18V and have capacity to run 8 or more trains from a ZW.

 Its description says it will only run two trains.   But I do understand the ZW and the other transformer do look cool.  I think any modern transformer is fine ..  and safe..  If you have good track wiring and keep your rails and equipment clean.

You are entitled to power and maintain your empire how you will. Any properly serviced transformer of any age is safe.

 

Well my own experience tells me a CW-80 will power a long string of incandescent lit passenger cars, and 2 other engines double heading 14 freight cars and a incandescent lit caboose.   For hours and hours.    I like the ZW and to CW. ..   Just trying to figure out the best route to take.   

carsntrains posted:

bmoran4 posted:

carsntrains posted:

So Lionel says a ZW of any type can run 4 trains with no problems.   What baffles me is if they can.  Why are many here only running two trains per ZW?? 

Those using ZWs are likely to be running in conventional mode with high current pullmor motors and incandescent lamps. A single train with dual motors and a long string of passenger cars full of lamps could easily pull almost triple digit watts. Additionally, while the ZW has 4 throttles, only 2 have whistle and direction controls, and thus the other two "throttles" are relegated to power some accessories.

How is that running circles around a CW-80 that I know will run 3 trains on one transformer for as long as you want them to run?   If it takes 2 ZWs to run 4 trains, or 5 ZWs  to run 10 trains, what advantage does it have over 4 or 5 CW80s running ONE train each? Or even 4 or 5 CW40s running 4 or 5 trains?   In 1954, 1923, or 2017 it just aint making sense to me??   Or that Z4000 or whatever it is.

Remember, transformers are rated on watts, not "how many trains" they run. A ZW is rated at 275 watts, the CW-80 only 80 watts. A CW-80 may be hard pressed to run that elegant dual pullmor motor loco with that long string of passenger cars. With modern can motors, command systems, and low power lighting, you could get away with using only one throttle set to 18V and have capacity to run 8 or more trains from a ZW.

 Its description says it will only run two trains.   But I do understand the ZW and the other transformer do look cool.  I think any modern transformer is fine ..  and safe..  If you have good track wiring and keep your rails and equipment clean.

You are entitled to power and maintain your empire how you will. Any properly serviced transformer of any age is safe.

 

Well my own experience tells me a CW-80 will power a long string of incandescent lit passenger cars, and 2 other engines double heading 14 freight cars and a incandescent lit caboose.   For hours and hours.    I like the ZW and to CW. ..   Just trying to figure out the best route to take.   

Bottom line, the ZW is equivalent to about 3 1/2 CW-80 transformers in terms of power output. If you find the CW-80 adequate, there is no issue.

bmoran4 posted:

Bottom line, the ZW is equivalent to about 3 1/2 CW-80 transformers in terms of power output. If you find the CW-80 adequate, there is no issue.

 Not really.  The PW-ZW is rated on input power, the CW-80 and other modern transformers are rated on output power.  200-220 watts is all you'll get out of the PW-ZW.

It sounds to me like the original breaker is shot. If you replace the internal breaker I would do it with a modern fast trip breaker designed to trip in milliseconds, not minutes, to protect the engines on the track, and also add a tvs across the track power circuit to stop surge. If not, I would recommend an external breaker, I believe Lionel makes one that is fast tripping, along with a TVS, I have seen adds for various devices like this that may include both breaker and surge suppression. The old post war motors didn't care, I can tell you that from experience, barring a major short in the engine itself causing the armature windings to melt their insulation, having had plenty of shorts that tripped my transformer as a kid, never fried anything, with modern engines with can motors and control boards, not going to be true. 

gunrunnerjohn posted:

 Not really.  The PW-ZW is rated on input power, the CW-80 and other modern transformers are rated on output power.  200-220 watts is all you'll get out of the PW-ZW.

That is correct, the continuous output rating of 2 CW-80s is 10 amps, about equivalent to a postwar ZW.

Once again in this thread, more pertinent information on-topic has been posted immediately above. So many of you gentlemen-hobbyists know so much information that threads such as these become invaluable reference resources for later use.

You help fellow hobbyists make decisions concerning a variety of matters, including how to expend their resources of money, time, and effort, not to mention their desire to have some fun and play around after a day or a lifetime of work.

Good job! Indeed!

FrankM

Here's a related question about connecting TVS diodes when running the newer electronic engines . . . .   if these are so inexpensive and tiny in size, why don't the manufacturers (like MTH, Lionel, etc,) just go ahead and put these in their engines?

Dave, that's a question for the ages.   It's a mystery to me as the TVS would be most effective right in the locomotive.

C W Burfle posted:

I use the outer handles to run trains ("A" and "D").
I use one inner handle to power switch tracks and the other inner handle to power uncoupling tracks.
That way I can tune the voltage differently for them.

Good thinking!   The CW-80 has an adjustable output on the accessory lugs.   Pretty cool feature really.   I hooded up a building the other night and it was too bright.  So poof just adjust the accessory output and it dimmed down a bit and looked fine. The downside to the CW-80s adjustment is you have to adjust it every time you unplug the transformer.

carsntrains posted:

The downside to the CW-80s adjustment is you have to adjust it every time you unplug the transformer.

That's incorrect, the accessory voltage should be retained until you change it.  It comes from the factory at 12V, and stays that way until you change it.

Just to make sure, I set mine to 6V and powered off the CW-80 for around 5 minutes.  When I turned it back on, the accessory output was still 6 volts.

Try having a fan blow on your ZW. No one has mentioned heat as a component of the ZW output.

An inexpensive line-side power meter (about $10 on eBay - free shippinb from Asia) can give some insight into what's going IN to the transformer.  These widgets have been discussed in other threads but the price has come down since they first became available.  Here one measuring a Z-4000 at idle (no load) showing 13 Watts going in from the wall.  Cranked up one handle to 16V AC with 4.4 Amp load (70 Watts) and now 101 Watts going in.  LCD a bit difficult to photograph.

Still requires some "do the math" to adjust for transformer efficiency and such, but another way to see what's going on.

Drummer3 posted:

Here's a related question about connecting TVS diodes when running the newer electronic engines . . . .   if these are so inexpensive and tiny in size, why don't the manufacturers (like MTH, Lionel, etc,) just go ahead and put these in their engines?

Ask your friendly neighborhood beancounter, even though a TVS would be trivial in cost (even at our level of price, at Lionel's, probably pennies), and isn't exactly hard to wire into the circuit (would go across the power leads), it is an 'extra cost' to them. Not to mention if a power surge blows out the unit, you then would be paying for new circuit boards at the very least. Beancounter will tell you every penny matters, and like with most things they do, it often means the consumer suffers. GM had a steering column to steering box joint that engineers specified 5 bolts, the beancounters made them cut it back to 3 (I think it was the late 60's Chevelle), and that is routine. 

I would think that if one manufacturer installed these in their locos, it would be a great marketing tool to use against the competitor who does not install them.

Drummer3 posted:

Sounds like I will try the 10-amp automotive type breaker, and add an external TVS on each post.  Thanks for all the tips!

All the current drawn from posts A, B, C, & D first passes through the ZW's circuit breaker.  If it's worn and out of spec adding an external breaker to each post is not going to prevent the main breaker from tripping.  Bottom line is that it needs to be replaced.  You still need to add a breaker & a TVS to each output to protect against voltage spikes and current surges from those outputs.

wild mary posted:

All the current drawn from posts A, B, C, & D first passes through the ZW's circuit breaker...

You would think so, right? But, that's not what really happens.

The single breaker in a ZW  is on the one wire feeding the "U" bus, to which all 4 "U" terminals are sweged to.

This is why it's so very important to avoid connecting the outputs of a ZW to each other when at all possible. Two handles set at different voltages have the potential to cause a 20+ amp fault current between them, with absolutely no overload protection.

What he said.  I saw my first one that happened to recently, it ate one of the rollers practically in two!  Obviously, a lot of current flowing!

Thanks Rob.  I learn something new everyday from you guys.

Adcx rob, this is a key point for all of us, I hate to waste your time but is it possible to give us a sketch on this u terminal breaker situation? Seems it will save us a lot of grief!

hokie71 posted:

...is it possible to give us a sketch on this u terminal breaker situation?

What he said.  I saw my first one that happened to recently, it ate one of the rollers practically in two!  Obviously, a lot of current flowing!

If that was the only damage, the owner was lucky.
This is the reason I suggest breakers on all four output terminals.
I even use them on the outputs that are dedicated to the switch machines and uncoupling tracks.

I don't have a photo of it, I gave it away to a forum member, but here is what I did to add protection to a Z. Should work fine on a ZW but I haven't actually done it.

I took a piece of Plexiglas and drilled eight holes to match the terminal pattern on the back of the Z. I drilled two extra holes on each end, for a total of twelve holes. I then put the T159/T160 replacement binding posts in the extra holes and slid the whole thing over the Z terminals. You will need a couple washers behind the Plexiglas. Connected PTC resettable fuses from A, B, C and D on the transformer to the four new binding posts. I put the PTC lead between the new binding post base and the Plexiglass so loosening the thumbscrew doesn't loosen the PTC wire. You will need to put sleeving over some of the PTC leads as insulation. 

Now you have added circuit protection to all circuits of the ZW without modifying the ZW or doing much rewiring of the layout or wondering about where/how to mount circuit breakers.

I mounted the extra terminals on the sides of the Plexiglas to prevent interference with the power cord on the Z. On the ZW you could probably put them above the ABCD terminals which would simplify the wire routing.

I used 7 amp holding current PTCs. Suit yourself.

Here's a picture of the current paths that don't go through the breaker in case anyone is still wondering.

Thanks ADCX Rob, GRJ is reading my mind in posting the paths in green.   so it appears, the issue can occur, if not careful on wiring to accessories etc and you have two hot lines at different voltages connected. 

Also, good idea from plcprof!

Thanks ADCX Rob, GRJ is reading my mind in posting the paths in green.   so it appears, the issue can occur, if not careful on wiring to accessories etc and you have two hot lines at different voltages connected. 

Or one might connect the "A" and "D" terminals to two different blocks on the same loop, and forget an insulating pin, or leave something stopped with it's pickup rollers bridging the two blocks.

Thanks CW, those hammer home very real examples. I am also amazed on the losses on our small transformers several have noted. Great learning thread as mentioned above.

For now, I temporarily added an external 10 amp breaker, manual reset.  I first tried a 15 amp, but it did not trip fast enough when doing 'shorting' tests.  In fact, smoke came from the where the roller rides against the coil before the 15 amp breaker tripped. So for me, the 10 amp was the ticket.   Now, I need to find a 10 amp automatic reset breaker to put into the case permanently.

 Also, I connected TVS's on the A and D posts, but they kept tripping the breaker as soon as I cracked the throttle.   So, not sure if I have the right TVS.  Specs are below.   Any ideas?

Drummer3 posted:

For now, I temporarily added an external 10 amp breaker, manual reset.  I first tried a 15 amp, but it did not trip fast enough when doing 'shorting' tests.  In fact, smoke came from the where the roller rides against the coil before the 15 amp breaker tripped. So for me, the 10 amp was the ticket.   Now, I need to find a 10 amp automatic reset breaker to put into the case permanently.

 Also, I connected TVS's on the A and D posts, but they kept tripping the breaker as soon as I cracked the throttle.   So, not sure if I have the right TVS.  Specs are below.   Any ideas?

 

 

 

 

I use 32 volt bi-directional TVS units from www.mouserelectronics.com  Not sure if you have correct rating TVS units or not. Also using 7 amp breakers on each output(A, B, C, & D) from my ZW. 

FYI: the internal circuit breaker on the post war ZW is rated at 15 amps and is on the common side.

Lee Fritz

OK, there's my problem.  I was using unidirectional TVS, not bi-directional.   Will try again.   Thanks Lee.

I use the 1.5KE36CA TVS diodes. Additionally, the smoke may indicate a loose contact in the arm and account for increased current draw under higher loads. 15 amp is the correct size breaker for the internal breaker, and is meant to protect the transformer, not the items it powers. Smaller breakers on each output is definitely the way to go in addition to the properly servicing the internals of the ZW.

On a post from a few years ago on Susan Deats web page,   (http://www.slsprr.net/technical/CircProt.htm)   she uses the PTC resettable breakers.

(positive temperature coefficient)

Would this be yet another choice for a ZW internal breaker?  It says 9A hold, but 18A trip?  Not sure what that means.

Any comments?

Dave,

Internally, use one of the specifically designed replacements for the ZW:

Z22: 

ZW-232:

Modern Automotive Bussmann 19115 assembly: 

Externally, I have known people to use PTCs (like the one you mentioned) attached to a terminal block for each individual output, but they take time to trip. You are much better off with a fast acting circuit breaker, many which have been discussed on the forum.

OK, just curious about those PTC breakers.   Thanks.

Drummer Dave, I question those ammeter readings you post above.  They sound way too low for old postwar equipment, especially with incandescent lighted passenger cars.  Are you sure you're using a good quality AC ammeter?  Running 2 freights and a string of LED-lit cars, about modern 6 motors running, I pull about 8 amps from my Z4000.

Drummer3 posted:

Hi GRJ,

Advance Auto, my local auto parts store has this automatic reset breaker, but is 14-volts.  Would this be OK for a ZW?   Or do I need to look for a higher voltage rating?

If suitable, I will pick it  up tomorrow, and not have to mail order.

 

 

 

 

 

 

 

 

I have been running with these 10 AMP  for years with no issue.  They work well. Also note the TVSs

I prefer breakers that must be manually reset, so they don't keep closing wbile you are working on the short.

Here's my $20 meter from WalMart, what I call the poor man's Fluke meter.  My son has a $169 Fluke I can borrow the next time he visits.

I will be able to compare amp readings then.

One of my passenger trains is a PS1  MTH hudson, which draws way less amps than a PW lionel engine.

The other is a 1992 AF MoPac set, (Missouri-Pacific) which also would draw less amps than a PW set.

OK, I was thinking you had all PW locos