ZW Transformer Question

[Anonymous]

My local train shop guy told me not to use my ZW transformer without a "gizmo" the buffers or filters the ZW ouput. The "gizmo" is $90 FOR EACH output lug and they were on back order.

He said the old power supplies can mess up the electronics on the newer MTH & Lionel engines. He seemed sincere but $90 bucks per output mounts up pretty fast.

Anybody have any experience with this?

Thanks

[iguanaman3]

Classic Zw's are compatible with all protosound and command control systems as is with no add on gizmo's. I run all types of trains with my old ZW and have never had a blown electronic board. Lionel powermasters even have their own fuse to protect it from overloading from a short on the track. Check your ZW circuit breaker by shorting a hot and common terminal with a screwdriver, it should cut off the power in about a second. Use common sense and turn off the power when there's a short and you'll be fine. You may want to add a fuse to your track outputs as insurance but they don't cost $90. Save your money for trains!

[spankybird]

Hi microbiz,

I tell you that I have two ZW and one KW on my two layouts. The only extra that I have added is a circuit breaker box that I built and a bell button. I have used these since 1997 with now having over 20 MTH PS1 and PS2 engines without any problems. Since I added DCS last year, I did add the circuit breaker box to protect the DCS. Please read this thread on fast acting breaker boxes.

http://www.trains.com/community/forum/topic.asp?TOPIC_ID=13672

If you are going to spend $90.00 per channel, times 4 channel = $360.00, you can buy a new MTH Z4000 for that price.



tom
ps, check out our layout by clicking on the web icon below

[Chris F]

It sounds like your dealer is recommending QSI PowerGuard spike arrestors. All Postwar and many modern transformers occasionally send high voltage spikes to the track, and these may cause problems for the electronics in modern locos. The units are reported to work well, but they are expensive.

If you are interested in a build-it-yourself alternative, the HiRailers group has some information for you:

http://www.hirailers.com/technical.htm

Keep in mind that a transformer circuit breaker is intended to protect the transformer, and nothing else. Postwar transformer circuit breakers are relatively slow to trip, so many hobbyists add quick-blow fuses or quick-trip circuit breakers to each hot line from their transformers. Please take a look at the thread indicated by spankybird. However, note that voltage spikes generally don't last long enough to trip a breaker.

[ben10ben]

There was quite an extensive discussion on this on OGR not too long ago. The general consensus was that they were a good idea, particularly with MTH PS-2 engines, which seemed to have the highest failure rate when used without spike protection.

If you don't want to spend $90 per output, a company by the name of Scott's Odds-n-Ends makes a 4 channel supressor that sells for less than a single QSI unit. Although I don't own one, I plan on buying a couple when I get around to building my layout.

http://www.scottsodds-n-ends.com/p8-surge_arrestors.htm

Also, if you are using an MTH TIU, you don't need to add anything else, as they have surge supressors for each of the 4 outputs.

[Anonymous]

Thanks all.

The PowerGuard is what he was recommending - even for the Z4000. I will check into the HiRailer/circuit breaker solution.

Thanks again!

[spankybird]

Gee Ben10Ben,

If a TIU (part of the DCS system) also does it (surge protection) , it seems to make more cents ($$$) to add DCS - protect your engines and also have commade control.

You can pick up DCS for $250.00 or so.

tom

[Anonymous]

sounds like snake oil/hogwa***o me.

has anyone EVER had a surge supressor/spike arrestor do it's job?

[spankybird]

I can honestly say, that I have never noticed a spike or surge and have never experienced a engine problem from that. Even if you did have one, do to the fact that we are using a step down transformer (approx seven to one, that is 120 volts to 17 volt), so would the spike be 1/7 the size.

Maybe because for the past year, I have been using DCS, therefore the TIU does it job. But then what about my other layout, which does not have DCS. Maybe I have just been lucky.

After all, I live only 2 miles from the First Energy plant that caused the big blackout last summer in the east.



tom

[Anonymous]

Spankybird:

These suppressors have nothing to do with spikes coming in from outside the house. These suppressors are designed to handle spikes on the other side of the transformer core, meaning those that originate on the layout. These are typically caused by derailments.

I think you're right about being safe from spikes coming in from outside, though.

Woodsy:

Spike arrestors are one of those things that you should never notice when it's working. You generally only notice the failures.

The fact is solid state electronics do have voltage & current limits that can be exceeded if a current path that the designer never intended develops, such as when one power pickup is on the center rail & the other is on an outside rail. This is different from a spike coming in from outside the house, since that has to go through the transformer.

I remember reading on the OGR forum a posting by someone (I forget who) that said they were having problems with the electronics in locos frying during derailments. Then they installed some spike arrestors & the locos stopped frying boards. Sounds like it worked for that guy to me.

The QSI units, from what I hear, are pricey. You can make a 4 channel arrestor from schematics published in the link Chris F included in his post above for about $30. It seems to me $30 is a reasonable amount to spend to ensure your $1000 locomotives keep working.

I hear good things about the Scotts suppressors, and a 4 channel suppressor for less than a single QSI powerguard sounds good to me, too.

Tony

[Anonymous]

I'm certainly no EE but I have to agree the surge supression is one of those things that you only notice when it fails! And it's not surges from the outside world that worrry me, (although they might be a big problem, just plugging the supply into a supressor would help) the worst ones are probably caused right on the layout.

A fair-sized transformer core (like a ZW's) stores a LOT of energy in its magnetic field, under certain conditions (like a momentary short/open circuit/short during a derailment) all that energy will dump right into the output.

A pullmore motor is a lot better able to cope with those surges than a microprocessor or a digital audio system.

Looks like one can make the simplest form of protection just by putting one of the parts mentioned in the High-Railer's article across the transformer output.

Here's the mouser P/N: 625-1.5KE33CA
Looks like they're a whopping 43 cents each! I'm buyin a bunch!

You'll need to build the complete circuit to be able to use full conventional whistle control at 18v with a ZW without clamping.

Have fun!

Old 2037

[Anonymous]

well...

it sounds like they need to design these new electronics a little better then. a simple de-rail can cause a spike great enough to fry the electronic boards??
sure, i understand a short can cause some whacky, unpredictable, voltage spikey things to happen but, i think it's sort of silly to sell transformers and locos that cant handle the problems of a de-railment. perhaps incorporating an item like the one OLD 2037 describes into the loco or transformer or TMCC/DCS items will help but why not build stronger units? i know that stronget parts cost more but if you dont have to go out and buy another widget... wouldn't you say that the company that did that is "taking care of thier customer"

[ben10ben]

Tom,
Some of us don't own any MTH locos, and don't ever plan to own any. For those of us in this situation, why buy a $250 piece when a $70 piece will do the same job?

[spankybird]

Well Ben,

My comment was based on the original quoted price of $90.00 per channel x 4 channels = $360.00. Complete DCS, remote and TIU is only $250.00 and you also would have command control for either MTH – DCS or TMCC.

It’s $110.00 less.

And you are correct that it looks like Scott’ unit at $70.00 would be better choice if you are never planning on command control.




tom

[Anonymous]

can anyone here explain how the spike arrestor device we are talking about works?

my understanding (i am a simple man) is that nothing stops ALL spikes, some devices shut off power VERY quickly (but still let a teensy smidgen of time pass before they can activate) , and some other devices "clamp or limit" voltage and available amperage to a certain level. what does an arrestor do?

[Anonymous]

"can anyone here explain how the spike arrestor device we are talking about works?"

Well I don't know what's in those expensive boxes but the 43 cent part I recomended is called a "bi-directional transient voltage supressor". It's basically a zener diode type thing that only conducts at 33 volts or more. It doesn't do much on anything until there's a spike in excess of 33 volts. Above that level it absorbs the excess wattage and turns it into heat, hopefully protecting anything else on the line. It will be destroyed by an excessive spike - but that's what it's supposed to do.

Old 3037