Circuit breaker to put in-line with my PW ZW

DennyM,

    I use the original Scott type 7 & 10 Amp Resettable Breakers, Scott was bought out some years back by Train Electrics, good company also.  You can find them on the Net. They still manufacturer the 10 Amp Scott type resettable breakers today.  I have been using them for many year, they never seem to wear out and work perfectly, never had a problem while using them between my Transformers and my TIU, on every Red IN Channel line.

No need to run at 20V, I run DCS/Legacy all the time at just below 18V, in fact Legacy should not be run above 18V Max, or you can damage the Legacy Engines - Right in the directions-

Hope this helps a might.

PCRR/Dave

These electronic circuit breakers are among the best I think. Really fast so there is no welding, etc. So much better than the typical circuit breaker.

http://www.traintekllc.com/dcc...ail-circuit-breaker/

I echo Chucks remarks and link.  The PSX line of circuit protection is top drawer.  Fast and easily adjustable to various AMP ranges.  

Bruce

I'll give a 3rd vote to the PSX-AC's. I agree with cjack and brucet47 above, and I use them myself on my own layout.

I use Blue Sea Marine thermal circuit breakers.  Push button reset.  Available in 5, 7, and 10 amps, with screw or push-on connectors, for about $6 each.  Available on line from most marine supply stores.

Pine Creek Railroad posted:

DennyM,

    I use the original Scott type 7 & 10 Amp Resettable Breakers, Scott was bought out some years back by Train Electrics, good company also.  You can find them on the Net. They still manufacturer the 10 Amp Scott type resettable breakers today.  I have been using them for many year, they never seem to wear out and work perfectly, never had a problem while using them between my Transformers and my TIU, on every Red IN Channel line.

No need to run at 20V, I run DCS/Legacy all the time at just below 18V, in fact Legacy should not be run above 18V Max, or you can damage the Legacy Engines - Right in the directions-

Hope this helps a might.

 

PCRR/Dave

I appreciate your advice Dave, but I never said I run at 20V I just want a circuit breaker that can handle up to 20V. I will check out Train Electronics.

Denny, don't bother looking for a breaker with a 20-volt rating.  Look for one 120 or higher.  I've never seen one with a limit that low, and besdies, if you're running 20 volts, peak voltage at the top of the AC sine wave is probably in the range of 27.  Voltage rating has nothing to do with the amperage at which a breaker opens; it is a measure of what voltage can be broken and what its insulation can withstand.

RJR,

   Blue Sea Marine Thermal Breaker -  Great stuff at Reasonable cost!  5,7 or 10 Amp  My old Scotts ever fail, Blue Sea gets the nod for replacements.  The reason I did not use them long ago, the Scott's were $7.50 for a breaker bank of 4, mixed any way you wanted, man I miss the original Scott's Business big time.

PCRR/Dave

I noticed that Dallee has a new line of circuit breakers.  They are a bit pricey but a nice looking panel mount breaker. They include spike protection.  

It's important to make a few remarks on the type of circuit breaker. There are thermal types and electronic types. In general, the electronic types are superior since they disconnect the load in an extremely (in terms of damage to the load) short time. In general thermal types allow some arcing and damage, and also allow for more likely damage to expensive electronics in the engines and rolling stock. Decades ago, electronic circuit breakers were not as necessary because the electrical parts in engines and rolling stock were more robust in the case of a short. When you compare the cost of the electronic type (usually 5 times the cost of the thermal type), it is money well spent, considering.

CJACK, I power all 4 of my loops each with there own 180 watt power houses which have very fast breakers, would the psx breakers be necessary ?

No. I also use powerhouses and they trip reliably and fast.

CJACK, Thanks for the quick response  !!!

Even though my system is powered by two Z-4000 transformers which have built in overload protection I also include a dual channel power monitor and circuit breaker panel for main track feeds. This panel includes dual voltmeters, resettable circuit breakers and power indicator lamps. This panel provides power to the track and MTH TIU outputs. My DCS system uses Passive Mode so no power is actually applied to the TIU input channels.

Cjack, there are also electromagnetic breakers.

Gerald, backing up the powerhouse breakers with thermals would only serve as a backup in case the powerhouse breakers were to fail, which can happen.

RJR posted:

Cjack, there are also electromagnetic breakers.

How well do those work...milliseconds to break, or longer?

Seeing as it's being discussed, does anyone have an actual figure on the response time of the breakers in the PH180 and PSX breakers?  Is it a few milliseconds, like 1 or 2?  10 ms? 50ms?  When folks say 'very fast' I'm not sure what is meant.  

Also, on these is the current rating an exact trip level?  ex do they not trip at say 9.99 amps and then trip the instant they hit 10 amps?( 10 amp rating) or do they allow some sort of over current to flow, for some period of time?

JGL

They just also say very fast. I take that to be less than 10 ms...fast enough.

Here...

http://www.dccspecialties.com/...s/pdf/man_psx-ac.pdf

CJack, That's all I found as well, hence the question on specifics.  Relative to a thermal breaker, 50ms could be "really fast".  Relative to a fast blow fuse, or the time it takes to blow up a microprocessor, however, 50ms is an eternity.  

There is a schematic floating around for the PH-180, not sure if it is "official" or not, but there appear to be errors in the scaling of the current transformer circuit, it can't possibly work as drawn.  The drawing does show two trip functions, an "instantaneous" function with a delay of about 7.5 milliseconds and a second function with a time constant of about 2.6 seconds. Due to the scaling issues noted above I can't accurately calculate exact levels and trip times, but it does appear to have both instantaneous and time-delay functions.

It also takes a short time for the relay to energize, but the PH180 is fast enough that you won't measure it's response to a short with a stopwatch.  You apply the short, and instantly you hear the relay click.  I'd say it's in the 10-20ms range, certainly not any longer.

I use Postwar Lionel #91 adjustable breakers. They trip instantaneously and can be had cheap on the 'Bay.

Roger

Chuck,

     There is little doubt that the electronic breakers are better engineering than the thermals, however the cost is 10 times as much, and I have never had any problems on my layout using the thermal low cost Scott type breakers.   Now if I ever do develop a problem, then I might consider going in that expensive direction.  1st however I would invest in the Blue Sea Marine resettable thermal Breakers, to make sure my very old $7.50, 4 bank of Scott Type Thermal Breakers, had finally failed to do the job correctly.  

Guns,

   If you run DCS and use the 180 Bricks with the great Fast Breakers they provide, rather than using a Z4k, you loose the dual channel capability of the Z4k and the side receiver that opens up so many more operating options, than the 180 Brick can provide.  I would much rather have the good Z4K Transformer, and even use the Scott type Breakers in front of it and the old ZW that has 4 operating Channels, than limit my layout operation with a 180 Brick, just because it has a good fast operating breaker.  The Thermal Breakers have been reliable thru many years of usage, and the Transformers, old and new give power options the 180 Bricks can never provide.

We always have looked at this in different engineering manners.

JGL,

   IMO there is no need for the expensive very fast action electric Breakers, when the inexpensive thermal breakers do the job just fine.  

PCRR/Dave

Dave,

Before I started using the 91s, I was using Blue Sea breakers backed by PTCs. I started with 10 amp versions and then went to 7s (they trip faster and the extra capacity wasn't necessary....I wasn't getting nuisance trips). Then I tried 5s and to my surprise, they were fine. But the 91s blow them away in terms of speed.

Roger

JGL, a fast blow only blows fast or a real bad short.  Apply 10.2 amps to a 10-amp fuse and time it; don't hold breath.  Fuse mfrs have blow time charts on their web sites.

Cjack, I've never used electromagnetics, so can't answer your question.  They should pull in as soon as enough current flows to create the necessary magnetism.  No question electronics are faster.  The Lionel #91 mentioned above is electromagnetic.

Dave, a lot depends on how your layout is set up and what you run.  Rarely do I run anything but DCS, so I have TIUs.  I use 4 variable channels and 2 fixed.  The latter have a Z4k receiver, and while the variables are set to fixed, a touch of the thumbwheel reverts them to variable.  So I replaced a ZW that fed 2 variable channels with a powerhouse 180 that feeds both.  Amazed at the breaker speed. The downstream 5-amp thermals have never opened since I added the powerhouse.

ROGER1 posted:

I use Postwar Lionel #91 adjustable breakers. They trip instantaneously and can be had cheap on the 'Bay.

Roger

Interesting, does anyone know or have an opinion as to their effectiveness with modern electronics?

Mike

Probably quicker than thermals but slower that electronics.

Remember that when there is a short on the tracks, that does not increase current flowing through the loco's electronics.  What is damaging is any sparks created by the derailment, the risk from which cannot belessened by a breaker but needs a TVS.

Roger,

   You noticed I avoided answering your post because although the #91's are a little more expensive, they are  probably one of the best options for Layout breakers on the market today.  I still believe they are just a little bit of an over kill, however I definitely agree they are great stuff, at a reasonable cost.  

RJR,

    Yep running both the Z4K & the 180 Bricks at the same time, is good engineering and I considered that option, Guns has been advocating the 180 Brick usage for many years and combined with the Z4k it definitely has it's usage on any bigger layout.  If you have 2 or 3 Z4K's with side receivers on each one, I see no need for the 180 Brick however and I chose to go in that direction.  The combination of both is definitely a big plus, and I can see why you went in that engineering direction.

PCRR/Dave

While focused on breakers, fuses,etc, don't forget..........

Breakers only protect the transformer[s] from overcurrent surges. Voltage will not trip a breaker. An inexpensive TVS [transient voltage suppressor] is essential for protecting fragile wires and engine component boards from voltage spikes . 

RJR posted:

Probably quicker than thermals but slower that electronics.

Remember that when there is a short on the tracks, that does not increase current flowing through the loco's electronics.  What is damaging is any sparks created by the derailment, the risk from which cannot belessened by a breaker but needs a TVS.

I will set up a test of the 91 trip time later today, it is easy enough to do.

To your second point, you are of course correct. A fast acting breaker doesn't prevent voltage surges, it just shortens the agony caused by a derailed truck as it drags along. 

PLCPROF, and GRJ, thanks for the information.  Sounds like like 20ms from time of short to time power is shut off would be on par with these devices, then.  

^{"IMO there is no need for the expensive very fast action electric Breakers, when the inexpensive thermal breakers do the job just fine.  "}

Dave, I agree there is no need for expensive breakers when you can get by with inexpensive ones.  I'm asking because I'm piecing together an option for inexpensive AND fast breakers and want to know just how fast something has to be, to be on par with the devices that are considered the absolute best.  

"JGL, a fast blow only blows fast or a real bad short.  Apply 10.2 amps to a 10-amp fuse and time it; don't hold breath.  "

RJR, I understand this, but it is the same for thermal breakers as well, which is probably why folks recommend 7 amp breakers for 10 amp transformers.  Honestly I just couldn't think of a better example of something that would trip pretty much instantly.  

Dewey, I agree that the primary purpose of the breaker is to protect the transformer, however even the painfully slow breakers original on postwar transformers are enough to do that.  The TVS are needed to protect from voltage spikes as you suggest, however a suitably quick breaker added after the transformer serves to protect the locomotives and layout as well.  With a derail where center rollers are shorting, or similar shorts, it only takes a moment to melt the wires from the pick-ups.  A good short from a wheel set across the track can equally cause damage to layout wiring.   For the best protection for everything, you need the TVS and a good breaker. 

JGL

JGL,

    I agree I have the 5, 7 & 10 Amp Resettable Scott Type Breakers in a couple of 4 bank set ups, and at that time, we could pick which Breakers we wanted in each Bank, kind of mix & match as needed, I have to admit I use the 7 & 10 Amp resettable thermals all the time and never have any problems at all.  My one concern was with the new LC & LC+ engines, Guns was advising me that I should consider use a lighter resettable thermal Breaker, with these particular new engines, so far I have had no problems with using the 7 or the 10's.  Do you see any problem with staying with them or should I go lighter on the loops where these newer LC & LC+ engines are mostly run?  I will probably be running 2 TIU's next Christmas season again, for the TVS protection in them.

PCRR/Dave

RJR posted:

Probably quicker than thermals but slower that electronics.

Remember that when there is a short on the tracks, that does not increase current flowing through the loco's electronics.  What is damaging is any sparks created by the derailment, the risk from which cannot belessened by a breaker but needs a TVS.

I've had direct shorts of an engine on the track cook the wiring before the thermal breaker disconnected. This latest one was a short of the common wire from front to rear trucks thru the tender. A fast breaker helps from wires getting heated up too. Actually that issue takes a lot more repair time than replacing a board. Although the board costs more, I realize.

Honestly, Dave, I would not use the 10 amp breakers for anything, unless you are running several dual-motor post war locomotives and lighted cars on that track and thus actually need more than 10 amps on the rails. 

In general I would use the lowest breaker you can get away with, without it tripping.  If you have the 5 amp ones laying around, I would use them, and only move to the 7 amp if you are having a problem with the 5's tripping when there is no short.  I would not run any modern locomotives, TMCC, Legacy, DCS, or LionChief, on a track with a 10 amp thermal breaker, as you will probably melt the pick-up wiring before the breaker trips.  

I've not done any research to confirm this, but I can't think of anything inherent in the design of LC engines that would make them any more susceptible to damage from a short than any other modern engine.  

Oh, wanted to add more to my questions... On the ph180, for example, what are the two stages?  is it something like say, at 11 amps shut off power instantly, at 10 amps leave power on for 20 seconds?  something like that?  actual current and times would be nice, but those don't seem to be available, so just a general idea?

JGL

One caveat with the powerhouse 180s.  Somewhere I read that Lionel is changing suppliers.  If true, the replacement supplier may or may not produce a product that is as good as the older powerhouses.

I note from experience that even a current within the limits of a 7-amp breaker can really heat an axle or do a job on the thin wires used in cars and locos when there is a cross-power-district connection and a short on either.  This is one reason I use 5's and 7's on my layout, rather than a 10-amp electronic (if I could find one reaosnably priced.)  The 7 is on a circuit that often sees 3 trains running, and as long as there is only one passenger train with incandescents, I'm ok. 

JGL: I totally agree with your recommendation to use smallest breakers you can get away with.  Your first 2 paragraphs are absolutely correct and good adv  ice.  One of the benefits of a thermal breaker is that you can use a small breaker and it won't pop on the slight or short-term exceeding of that rating.

JohnGaltLine posted:

 

---

Oh, wanted to add more to my questions... On the ph180, for example, what are the two stages?  is it something like say, at 11 amps shut off power instantly, at 10 amps leave power on for 20 seconds?  something like that?  actual current and times would be nice, but those don't seem to be available, so just a general idea?

JGL

 

OK - Just killed a morning modelling the PH-180 schematic, I don't have a real one to play with. However, I can say the following with 95% certainty.

There is a definite value that will cause a time delay trip. The maximum delay will be 10 seconds. For sake of discussion, lets call this value MAX AMPS.

As you increase the load, the delay decreases, as would be expected. At 1.5 times MAX AMPS, the delay will be 3 seconds.

There is an instantaneous function that trips the breaker at an INSTANTANEOUS value of 2.5 times MAX AMPS. Note that this is INSTANTANEOUS, NOT RMS. If we use the convention that peak value of a sine wave is 1.4 times the RMS value, this means that we will get an instantaneous trip at the peak of an RMS current of 1.785 times MAX AMPS.

There is an electronic delay of 7.5 milliseconds in both trip actions, BUT, the unit only responds to overcurrent on only one polarity of the output waveform, so, worst case, your instantaneous trip would occur in 7.5 ms + 8.33 ms plus the relay pickup time, as GRJ points out.

This is all contingent on conventional current transformer usage, there are design tricks that can use CT saturation to modify trip curves. If I knew the exact CT parameters and circuit values we could give better numbers.

To sum up-

10 second delay at MAX AMPS

3 second delay at 150% of MAX AMPS

Instantaneous trip at 250% of MAX AMPS

Fastest repeatable trip time is 25 - 30 ms or so. Might be quicker depending on exact timing.

JGL,

   2 of my lines at times see original Lionel Conventional Tin Plate Consists with multiple  search light Cars, along with the double headed GG1's and the 15 big lighted Silver PRR Passenger Cars, and the Williams double motored Conventional UP, City of San Fran, with it' 8 big 21 Inch Passenger Cars, draws some serious voltage also, so a couple of my lines require the 10 Amp Breakers on them, and they will have to stay that way.  I am considering the newer 5 Amp Blue Sea Marine thermals, for the LC & LC+ inner RealTrax loops however.  Got to say my 10's all Break on the light side, so I have never had any problems.  I do like the 7's but sometimes need the 10's on certain loops, however the big Christmas Box Car Train, runs with the 7 and never has any problems at all having just the Lighted Legacy NP Engine or P2 GG1 Engines and Caboose, with a couple operating cars only.  The double headed Masonic Train actually rans on the inner RT inner Loop on the 2nd level, with a 5 and never popped the 5 Amp Breaker, even with 4 lighted Cabooses.  I did find out those beautiful Weaver 0-8-0 Conventional Engines take very little power to operate.  You are making a good Engineering argument about using the lighter 5 Amp resettable thermal Breakers, may need to pick up a few more, for the next Christmas layout.

PLCProf,

    Thanks for the 180 Breaker engineering break down, interesting stuff for sure.

PCRR/Dave

PLCPROF, Thank you, and hopefully you had some fun with your morning, at least.

To more or less repeat, we're looking at max amps delivered for 10 seconds. (lets say 10 amps.[RMS])  150%max amps delivered for 3 seconds. (15 amps [RMS])  then we have 250% max amps for 0 seconds, but peak of wave, not RMS.  If I did my math right, which I might not of, it would average out to 175% of max amps RMS over time, or in the example, (17.5 amps) Plotting these values on a graph is showing a straight, linear progression for the cut off time to over current ratio of about 7.5% over current for every second, or on the 10 amp device example, every .75 amp over current drops the on time by one second.  

For the purpose of duplicating the functionality, I would have to tell the circuit to follow that ratio based on the average of RMS readings, but also program it such that any single reading of over 250% of max amps causes a fault as well.  

Seems pretty straight forward to me not.  Thank you for the actual numbers.  

JGL

You all are way ahead of me in the inter workings of these things, but since I use both the PH-180's and PSX-AC's I will share my experiences, FWIW. My tests are far from scientific and are really just my experience from actual usage.

The PH-180's breakers are very fast and the PSX-AC's are just a little bit faster. They trip before the PH-180's. To be fair here I have my PSX-AC's set to 8 amps (they don't have a 10 amp setting) and the PH-180 is 10 amps. The PSX-AC's also include surge protection, I am not sure about the PH-180's, but I don't think they do? Going from past threads and posts by others more knowledgeable here on the forum, I would still recommend using some extra TVS's with either or both items and I have also added a few to my layout for extra protection. As others say, they are inexpensive and easy to add, so why not add them?

To expand on what cjack said above about the PSX-AC's being about 5 times more than the thermal breakers, the cost of replacing the electronics in just one engine is roughly about 5 times the cost of a one PSX-AC. Possibly more if you don't do your own repairs?

The PSX-AC's are not inexpensive (about $50), but to me they are worth the extra cost and extra protection. If they save just one engine I am way ahead on costs and have actually saved money. They also have some extra bells and whistles as an added bonus like remote reset, configurable trip settings, alarms and LEDs that you may want to take advantage of as well. Also, $50 is not a lot when people are spending $500-$1800 or more on a modern command control engine. That's probably less than the sales tax on many of those engines.