PW ZW Questions

One thing I would do is clean all the carbon off the copper coil.  It appears that that one carbon wheel may not be turning since it is leaving such a mark.  It may need to be replaced as it looks to be nearly worn away.  Others will tell you more, I'm sure.

Dennis

If your cord is fine, the only internal I would bother with are the rollers. In one photo, one looks particularly worn, so I would just replace them all. They are inexpensive and easy enough to replace.

To fully "modernize" the ZW, you need to add TVS diodes and fast acting circuit breakers externally. The TVS protects against over voltage, the breakers over current. You need both.

The recommended TVS is the 1.5KE36CA.

The TVS diode protects against voltage spikes caused by collapsing electromagnetic fields generated by the layout (relays, solenoids, motors, derailments etc).

A short video about those spikes:

Since the source is layout side, you want the protection layout side. Many people put them on the track, others put them on the output terminals of the transformer, and some do both!

With a ZW, it is easy to take 4 TVS diodes, shape them like this so they wrap around the binding posts, (A-U, B-U, C-U, D-U).

As for circuit breakers, you can get by with 10 amp breakers from the auto parts store. There are those on the forum that have favorite models, seek exceptionally fast trip times, or dial the breaker rating for their load rather than the supply (nothing wrong with all that, just makes things more complicated than they sometimes need to be).

You should also be made aware that you can use solid state diodes (1N1190AR) to replace the copper disc rectifiers, but you can cross that bridge if/when you need.

bmoran4 posted:

If your cord is fine, the only internal I would bother with are the rollers. In one photo, one looks particularly worn, so I would just replace them all. They are inexpensive and easy enough to replace.

To fully "modernize" the ZW, you need to add TVS diodes and fast acting circuit breakers externally. The TVS protects against over voltage, the breakers over current. You need both.

The recommended TVS is the 1.5KE36CA.

The TVS diode protects against voltage spikes caused by collapsing electromagnetic fields generated by the layout (relays, solenoids, motors, derailments etc).

Since the source is layout side, you want the protection layout side. Many people put them on the track, others put them on the output terminals of the transformer, and some do both!

With a ZW, it is easy to take 4 TVS diodes, shape them like this so they wrap around the binding posts, (A-U, B-U, C-U, D-U).

As for circuit breakers, you can get by with 10 amp breakers from the auto parts store. There are those on the forum that have favorite models or seek exceptionally fast trip times.

Very helpful, thank you. Is there a PN for the roller kit you've shown or can I just get it from ebay? Click Click 2

Do the diodes go ->| against the lettered posts? Gonna hit it with some tv/radio contact cleaner to get rid of the graphite streaks on the coils too. I've also heard about diodes on the whistle / reverse switches. Mine don't whistle all that well and there's an increase of speed when they do. Is there anything I can do about that or is it just the way it works?

Thanks

@SteamWolf,

I'm not aware of any universal kit, but may parts suppliers make up their own using V-45 rollers and ZW-102 rivets. That looks to be what you have linked to.

You need at least 4 TVS diodes. If mounting to the transformer, they go up and down between A-U, B-U, C-U and D-U.

Contact cleaner is a great way to clean the coil surface.

I haven't heard anyone regret upgrading the rectifier disc with the 1N1190AR diodes. The ZW (and most other transformers) add a 5 volt boost when the whistle is engaged to compensate for the extra electric load when activated. Generally speaking, a weak whistle has nothing to do with the transformer's rectifier/diode. If it is successfully signaling activation, then the weak whistle is due to the unit itself.

bmoran4 posted:

@SteamWolf,

I'm not aware of any universal kit, but may parts suppliers make up their own using V-45 rollers and ZW-102 rivets. That looks to be what you have linked to.

You need at least 4 TVS diodes. If mounting to the transformer, they go up and down between A-U, B-U, C-U and D-U.

Contact cleaner is a great way to clean the coil surface.

I haven't heard anyone regret upgrading the rectifier disc with the 1N1190AR diodes. The ZW (and most other transformers) add a 5 volt boost when the whistle is engaged to compensate for the extra electric load when activated. Generally speaking, a weak whistle has nothing to do with the transformer's rectifier/diode. If it is successfully signaling activation, then the weak whistle is due to the unit itself.

Ok, I wasn't aware that the TVS diodes were unidirectional. I'll search for those parts on the bay/amazon, (hopefully all from the same seller) and see what I come up with. Thank you for your help, should be a short duration on the healing bench for this guy.

With the known problem of high resistance brushes, has anybody checked replacement transformer rollers?
I have some that I purchased a long time ago, I am going to check a few today.

I'd like to thank bmoran4 for his clear answes to the original post. And thanks for going to the trouble to include the pictures - they showed how "do-able" the installation of a TVS should be.

A couple of folks have suggested replacing all the rollers.
While I understand the sentiment, I don't agree.

I have had quite a few ZW transformers on my bench. Often only one roller is worn.
I think this is because many ZW's were sold to people with the idea of having capacity for expansion that never came. So only one handle was used. The other handles may have powered accessories, but they were moved around very much.

Regardless, I suggest reading the two Lionel factory service manual sections on the ZW and ZW-R. (links below)
In them you will find suggestions on service, including a technique to replace rollers. The control arm can be damaged if it is done the wrong way (bent).

Thanks to Olsen's for providing the manual online!

ZW service
ZW-R service

The "cotton" stove wire MIGHT be asbestos...if so, not to worry, disturb  it as little as possible...wash your hands or use gloves....all the best, Joe

 

Regardless, I suggest reading the two Lionel factory service manual sections on the ZW and ZW-R. (links below)
In them you will find suggestions on service, including a technique to replace rollers. The control arm can be damaged if it is done the wrong way (bent).

Thanks to Olsen's for providing the manual online!

ZW service
ZW-R service

I think my "A" roller was the one used most and what you said is probably what happens more often than not, especially with "B&C". The parts are cheap and I'm in there anyways so...

Thanks for the FSM! Good thing to have!

joe krasko posted:

The "cotton" stove wire MIGHT be asbestos...if so, not to worry, disturb  it as little as possible...wash your hands or use gloves....all the best, Joe

I'll lick it just to be sure! 

SteamWolf posted:

joe krasko posted:

The "cotton" stove wire MIGHT be asbestos...if so, not to worry, disturb  it as little as possible...wash your hands or use gloves....all the best, Joe

I'll lick it just to be sure! 

That's good thinkin'!   

Transient Voltage Suppressors (TVS) about $.50 each.  1.5KE36CA bi-directional  diodes from Mouser. 

Below: A railpower distribution strip extended out remote from the power center or transformer. The objective is to enable at least 5 separate railpower hookups to outer rail and center rail on a single power district to prevent power "vacations" in a District or Loop .

Aso below, is shown a plate-jumpered, 6 position strip to create 5 energized take-offs for Hot (green) and 5 for the Common (white) with a TVS wired directly between ( correctly wired like a direct short) .  The Green and White conductors are extended from a 180 watt powerhouse. But substitute the "U" wire from a pw ZW to the White and from the A (D,B or C) to the Green and you have the same electricall hookup.  NOTE: I cut the cumbersome connectors off my Powerhouses and solder on spade lugs which will connect to any screw terminals such as a T-Strip or on a TPC or TIU.

 Below: protection at the pw  ZW terminals  (use serrated lock washers for retention/tightness).

Dewey Trogdon posted:

Transient Voltage Suppressors (TVS) about $.50 each.  1.5KE36CA bi-directional  diodes from Mouser. 

 

Below: A railpower distribution strip extended out remote from the power center or transformer. The objective is to enable at least 5 separate railpower hookups to outer rail and center rail on a single power district to prevent power "vacations" in a District or Loop .

Aso below, is shown a plate-jumpered, 6 position strip to create 5 energized take-offs for Hot (green) and 5 for the Common (white) with a TVS wired directly between ( correctly wired like a direct short) .  The Green and White conductors are extended from a 180 watt powerhouse. But substitute the "U" wire from a pw ZW to the White and from the A (D,B or C) to the Green and you have the same electricall hookup.  NOTE: I cut the cumbersome connectors off my Powerhouses and solder on spade lugs which will connect to any screw terminals such as a T-Strip or on a TPC or TIU.

 

 Below: protection at the pw  ZW terminals  (use serrated lock washers for retention/tightness).

 

Right on, that was the plan. I ordered a pile of TVS dioded off of Digi-Key this morning with the diodes for the whistle switches. One shorted across track supply on the bus board, the other on the back of the transformer. 

Was going to use A for train control, B&C for accessories and the 1121pw switches and D for the trolley line. 

Ive asked before but no response.  TVS's go bad sometimes.  How do you know?  Periodically check all for continuity?

Train Nut posted:

Ive asked before but no response.  TVS's go bad sometimes.  How do you know?  Periodically check all for continuity?

I think just a continuity check would work... 

SteamWolf posted:

Train Nut posted:

Ive asked before but no response.  TVS's go bad sometimes.  How do you know?  Periodically check all for continuity?

I think just a continuity check would work... 

@SteamWolf, Incorrect, more factors than simple conductivity at play here.

@Train Nut, TVS diodes are indeed a wear item. There are two failure modes. The first is easy to detect - a dead short. Then there is the degraded mode which is difficult to detect without extensive testing.

You can read more here: https://www.microsemi.com/docu...-voltage-suppressors

bmoran4 posted:

SteamWolf posted:

Train Nut posted:

Ive asked before but no response.  TVS's go bad sometimes.  How do you know?  Periodically check all for continuity?

I think just a continuity check would work... 

@SteamWolf, Incorrect, more factors than simple conductivity at play here.

@Train Nut, TVS diodes are indeed a wear item. There are two failure modes. The first is easy to detect - a dead short. Then there is the degraded mode which is difficult to detect without extensive testing.

You can read more here: https://www.microsemi.com/docu...-voltage-suppressors

 

A meter set to Ohms/continuity should tell you if it's shorted and if you have a stack of them, there should be an average "ok" number for resistance?  Your linked report says basically it'll be shorted or there'll be a big sh*t stain on the part where it overheated and leaked.

It's not a satellite, it's a toy train.

So after a half hour of screwing around, I managed to get everything fingered back out. This was great, ordered the parts y'day and they showed up today sometime. Love Fedex. I'm just waiting on the rollers now. 

I am a little concerned at what the contact cleaner did to the varnish on the top winding... hopefully it doesn't short out now. 

TVS Diodes mounted too. I plugged it in and poked the terminals with my multimeter... it showed 7-21vAC with an appx 5v spike when I hit the whistle switch. I don't think the breaker had ever worked before this, as I had found a wire inside had become loose. The red light blinks just fine now and clicking can be heard from inside. I'm still going to replace the unit with a 5A automotive breaker and get a 10A too just in case. Lastly, when I was cleaning it, I noticed on the bottom under the metal stand it had stamped ZW-12. Any idea what the 12 means?

Thanks for all the advice and part numbers!