Trusty Lionel ZW

That really rings true, the saying, "They don't make them like they used too".

I run my DCS/TMCC layout with an old (refurbished) ZW.  No trouble in all the years since DCS and TMCC came out.

.....

Dennis

Dennis,  do you have a circuit breaker in the line?

In addition to fusing the Hot conductors connect a TVS across the binding posts[across U & A for example] of each power district to absorb voltage spikes.

I just bought some 7 amp breakers from Mouser electronics to use with my old ZW. Already have the TVS units.

Been reading too many horror stories about the newer ZW's(ZW-C to ZW-L) on the forums, anything from cross circuit voltages(output voltage from handle A going to handle D) to handle falling off when in use. Besides I like my transformer to have all it's stuff inside it(I hate the power brick idea).

Lee Fritz

"They Don't Make Em' Like They Used To"      So Very True 

While I'm not using, Lionel's ZW. I do believe in using refurbished prewar units. I'm using three Lionel Z Type on my prewar layout. The vintage Lionel Std Gauge engines do require more power than most modern transformers can provide. I'm also using postwar units. Which are two KW's and two TW's..There may be those that disagree. They too are entitled to have an opinion of their own.

Least I forget the modern units, one Z4K, two Z1K's and two Z750's.

I am using the trusty old ZW my Dad purchased for me in 1962 along with 3 KW's, one z and 3 or 4 R's for light's acessories. I use the ZW and 3 KWs to power each of the four independent loops on my layout and have 3TMCC Track Power Controller Units for 3 of the loops. I have added in line 5 amp circuit breakers to protect the the modern circuitry as the older unit circuit breakers rarely blow before 9 amps, a bit too late for the new electronics. The Old ZW/KWs along with the TPC are a marriage made in heaven.

Cheers

Ralph

While 5 amps may be a little bit on the low side and 10 amps is too much, I think that 7 amps is better, at least that is what is on the MTH Z-1000 transformer.

Just got my 7 amp breakers from Mouser yesterday, didn't get time to test them yet.

I bought some of the TVS units like what Dewey suggest using. Are they bi-directional and what voltage range? I am asking so that others may find the part easier on the Mouser website.

Lee Fritz

I'm using 2 1950 ZWs (+ a KW & a Z4000) on my DCS-equipped layout.  The only refurbishing they've had is replacement of the rollers and repair of binding post connections to the internal U buss. Given that the handles are rarely moved, I expect the rollers to outlast me.

ZW output is a pure sine wave at any voltage, so the output is perfect electrically for modern eqpt, with proper external protection.  I use 5- & 7-amp breakers

Vinny,

   I use the ZW's, KW's & Z4K with 7-10 Amp Scott type Breakers, everything works great.

Definitely use the breakers or fast blow fuses to safe guard your TIU. 

PCRR/Dave

More than the TIU is at stake.  How about your house?

Wow, thanks for all the information.   I didn't know about TVS's.   Do you have a part number for the TVS?

Good question.  Mouser has a lot listed.  If you use DCS, I am told that the TIU has protection built-in.

I only have a few TMC engines and one MTH engine that run in conventional mode.  So, I have an old type TMC system 

Transient Voltage Supressor:

Mouser P/N 576-1.5KE36CA

Mfg. P/N 1.5KE36CA

Mouser phone: 1-800-346-6873 

Bi-directional, 36 volt.

You need one connected across the line between the Hot and Common for each railpower district or for each throttle. For example on a post war ZW wired between "A" & "U", "D" & "U" at the transformer or downstream on a terminal strip. Not needed on "C"& "B" if throttles not used for railpower.

Or, if talented have gutsand desire the perfect location, connect inside the engine from a pickup roller wire[the Hot] to the engine frame[the Common].

2 questions:

Since any spikes would more probably be generated out on the layout than coming through the house wiring, if one is using DCS, should not the TVS be across the output terminals of the TIU to prevent the surge from reaching it?

Would a voltage rating of less than 36 volts, but more than the AC peak (not RMS) voltage on a layout be able to afford more protection to devices?

RJR,

Spikes or surges occur most commonly from your power supply or transformer as the input voltage may climb to 128.5 volts(although plugged into a 120 volt circuit) and be legally safe for residential use by the NEC(National Electric Code), so that is why the transformer or power source for your trains needs to be protected by the TVS unit. A voltage spike may occur with a derailment or a short as power goes back to the transformer quicker and may cause a momentary higher voltage.

If you want to be more safe install a TVS in each new engine with a circuit board inside it.

A 32 volt TVS might be better but is one made currently? That is most likely why Dewey said to use a 36 volt TVS.

Lee Fritz

Thanks, Lee. I wonder if 35 volts on the track would damage in-loco components?  I assume the 36-volt rating is peak, not RMS????

I don't think there is any worry about a postwar ZW being damaged by a surge or spike, but the modern downstream equipment is a different story.

Which raises another question in my mind, The source of a spike on a layout will probably be a running derailment.  Does having a TVS between derailment location and in-loco electronics (in other words, in the loco), afford more protection than a TVS that is upstream from both derailment and loco (in other words, at transformer or TIU output?

Back in the day my use of the 36 volt TVS came from several EE's including Dale Manquen on OGR Forum. If I recall correctly, and more recently, Gunrunner John EE and very helpful guy on OGR Forum agreed.

I am merely an obsolete "Sparktrician" and as the saying goes somewhat "cognitively impaired" between the ears via a '09 stroke and many birthdays.

RJR,

The answer about the TVS was posted before and I will re-post it, yes putting a TVS unit in each engine is much safer then just at the transformer output, because if you forget and put the engine on a track without a TVS unit you may damage it if a short occurs.

Do you take any of your engines to a friend's house or club layout? If so then install the TVS in each engine and you won't go wrong.

The cost of a TVS unit is very reasonable compared to the price of replacing a circuit board.

Lee Fritz

Thanks again, Lee.  I fall into the category of what Dewey calls an old sparktrician and am trying to keep up, to learn as much as I can digest.