ZW circuit breaker?

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July 23, 2012 6:57 PM

How do you tell if a Postwar ZW 275Watt circuit breaker is working? If it wasnt working would it be ok to remove it and just put fast blow fuses on each line?

 

Liam 98 

 
 
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July 23, 2012 7:16 PM

Put a screw driver or large gauge wire between the A ,B,C,or D post and the U terminal and turn up the throttle. It should trip after a period of time. If the breaker is bad replace it with a suitable replacement. This is necessary to protect the transformer and will protect heavy bus wire but not thinner branch wires. For running modern engines add appropriate external protection,described here. 

 

http://www.jcstudiosinc.com/BlogShowThread?id=486&categoryId=

 

Dale H

 

Another fine product of the Cleveland Public School system.

A nice site to visit is J&C Studios.

 
 
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July 23, 2012 7:22 PM

The 5F circuit breaker test for the ZW transformer places a .1 ohm (one tenth) resistor across the output terminals of the transformer.

With this load, the 5F manual says the current should be 30 amps (thirty), and the circuit breaker should take between 11 and 40 seconds to trip.

 

IMHO that is a lot of current, and an awfully long time, which is one of the reasons I aways use postwar Lionel #91 adjustable electromagnetic breakers on all the power posts that are in use.

The internal breaker is there to protect the transformer. It probably would not protect your wiring or anything else very well.

 

The resistance load in a Lionel test bench is a heavy piece of nichrome ribbon.  They get HOT!

 

I absolutely would not use a postwar Lionel ZW transformer that did not have a properly working circuit breaker.

 
C.W. Burfle
 
 
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July 23, 2012 7:22 PM

If the breaker is bad is there a risk of doing that such as fire or damae o transformer. So you say turn up one throtle or all.

 

Liam 98 

 
 
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July 23, 2012 7:30 PM

Dont matter which throttle as long as you connect the appropriate taps.Should work the same on all 4 AU,BU,CU and DU. The breaker protects the transformer so it must function as CW Burfle says.  Without it you could have a meltdown. Never leave any transformer modern or old unattended and plugged in.

 

Dale H

 

Another fine product of the Cleveland Public School system.

A nice site to visit is J&C Studios.

 
 
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July 23, 2012 7:46 PM

Now i have in line fuses but before it melted and external wire going to a lionel lighted bridge the light dimed but no red light.

 

Liam 98 

 
 
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July 23, 2012 9:02 PM

Note that while the ZW transformer circuit breaker protects the individual outputs, there is one large hole in it's protection!  If you short two outputs together and they're set at different voltage settings, there is no path through the circuit breaker for that case, and it'll just suck down juice until something melts!

 

TCA, North Penn O-Gaugers, MTH ASC Certified Technician

Super-Chuffer @ Henning's Trains

 

Nothing is so easy as the job you imagine someone else doing.

 
 
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July 23, 2012 9:39 PM

I would test the breaker as suggested above. If it doesn't trip replace it with one from a parts dealer like Jeff Kane at www.ttender.com

Part number ZW-232 for the type mounted to the aluminum bracket or Z-22 for the square black type mounted to the bottom of the case.

 

ZW's are encased in Bakelite which doesn't melt so yes you can fry the wires and coil inside but good luck getting the bakelite case to burn, melt etc. I've tried a propane torch on Bakelite.

 

Kent S.
Rocky Mountain Toy Train Show Co-Chairman
Rocky Mountain Toy Train Show

Tranz4mr's website

 
 
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July 23, 2012 9:58 PM

Originally Posted by gunrunnerjohn:

Note that while the ZW transformer circuit breaker protects the individual outputs, there is one large hole in it's protection!  If you short two outputs together and they're set at different voltage settings, there is no path through the circuit breaker for that case, and it'll just suck down juice until something melts!

The ZW has NO protection for the individual outputs.  Only the common bus has the circuit breaker, hence the problem you describe above.

 

Rob

 
 
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July 23, 2012 10:25 PM

Where do you find the circuit breaker and will fast blow fuses completely drop power on track to 0
?

 

Liam 98 

 
 
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July 23, 2012 11:13 PM

The ZW breaker is under the top cover. Replacing a ZW breaker requires soldering. Newer ones have it mounted to the aluminum bracket while older ZW's have it attached on the bottom base.

Fast blow fuses attach to the A, B, C and or D terminals that you are using. Another way is to go to the link that Dale H has in his post near the top of this thread..

 

Kent S.
Rocky Mountain Toy Train Show Co-Chairman
Rocky Mountain Toy Train Show

Tranz4mr's website

 
 
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July 23, 2012 11:34 PM

I cant find it someone be so kind to show a picture. I hope there is a circuit breaker  If not i am ordering one and putting it out of service until it comes!!! Do you mean under the coil or on top. Ny model has the big coil with the l logo with no writing around the L.

 

Liam 98 

 
 
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July 23, 2012 11:41 PM

Here it is in a video I made when i first got it.

 

 

Liam 98 

 
 
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July 24, 2012 6:32 AM




quote:




Note that while the ZW transformer circuit breaker protects the individual outputs, there is one large hole in it's protection!  If you short two outputs together and they're set at different voltage settings, there is no path through the circuit breaker for that case, and it'll just suck down juice until something melts!





 

This is the second reason for using external breakers on each of the "Hot" terminals in use. The ZW transformer can be damaged by a short as described by John. I have seen it.

 

Unlike working on the trains, there are safety issues associated with working on transformers. There is house line voltage involved, and the transformer has exposed line voltage connections. Folks should consider this before working on transformers.

 
C.W. Burfle
 
 
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July 24, 2012 10:49 AM

Can someone suggest a 10 amp fast acting breaker? I went to Napa auto parts, and purchased some 10 amp thermo breakers, but by the time they heat up and trip, everything would have melted to the tracks.
 

 
 
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July 24, 2012 11:17 AM

I use Postwar Lionel #91 adjustable electromagnetic circuit breakers.

They trip instantly.

 

They usually can be purchased for between 10 and 20 dollars each.

 
C.W. Burfle
 
 
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July 24, 2012 11:26 AM

Fast acting fuses or breakers rated near 8 amps should work very well for each lettered(A, B, C, D) output on the older 250 & 275 watt ZW's.

The way Lionel has the older ZW set-up is that only the return or common wire has circuit protection. As one or two others have mentioned before, you can almost weld with the older ZW's before the internal breaker trips.

 

J Daddy,

Thermal breakers are for use with stuff like air conditioning in a car. Personally I stay away from D.C. circuit protection in an A.C. envirement.

Lionel transformers put out A.C. voltage, your auto has D.C. voltage, so using auto circuit breakers is not the best thing to do.

For the average person to understand about electric work like A.C. and D.C. volts, D.C. is straight power like a battery, A.C. fluctuates between positive and negative many times a second-thus the name alternating current.

 

Lee F.

 

Philadelphia & Reading Railway, one of the first railroads in the USA, first to have a double track system in the USA.

 
 
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July 24, 2012 12:30 PM

Liam, On Kent's Website
see ZW Checkout

 

Here's a photo of the postwar ZW insides for circuit breaker location.

 

 

ZW Inside Back small

 

Susan's Run Room http://www.slsprr.net/

 
 
Photos (1)
ZW Inside Back small
 
 
 
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July 24, 2012 1:45 PM

Thanks guys. I am removing the DC thermo breakers tonight.  The #91 breakers look to be sufficient but expensive(@20.00 each). Are they hard to find? Is there something I can buy at the hardware store?
 

 
 
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July 24, 2012 1:52 PM

Just regular fuses for use with 25 to 50 volts A.C, 7 or 8 amps, up to 10 amps but no higher. Put a fuse in each letter, A to D, output of the ZW.

Radio Shack may have fuses, but make sure they are for under 60 volts.

 

The Lionel # 91 breakers may seem expensive at first, but what would it cost to replace something?

 

Lee F.

 

Philadelphia & Reading Railway, one of the first railroads in the USA, first to have a double track system in the USA.

 
 
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July 24, 2012 1:59 PM

True, way too much. If I went the fuse route however, my luck I would run out or worse yet put them away where nobody would find them. Thus the breaker route
 

 
 
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July 24, 2012 2:00 PM

The postwar Lionel #91 breakers aren't too difficult to find, but one does have to keep an eye out for them.

One word of warning: If the adjusting knob on the #91 is turned down too tightly, the breaker will never trip. Sometimes you find them with melted cases. I'd steer clear of those because they were probably abused (by screwing the knob down too far.

I have been using the same ones for over thirty years, and have never had one fail.

 

I adjust mine by putting the biggest load I am going to run on the tracks, and loosening the knob until the breaker trips. Then I turn the knob back down 1/2 - 1 turn, and it's all set.

 
C.W. Burfle
 
 
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July 24, 2012 2:05 PM

Good to know, thanks. I will keep my peepers open for them. I have never seen them at train shows.
 

 
 
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July 24, 2012 4:30 PM

I can be counted as one who used a PW transformer to power a locomotive with modern electronics. The result wasn't pretty. Member Superwarp did a review on PSX circuit breakers: http://ogrforum.ogaugerr.com/d...ent/3259945169936428  These look to be an excellent choice for protection between transformer and track.
 
 
 
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July 24, 2012 5:29 PM

If I didn't have the Lionel breakers, I'd probably buy those PSX breakers.

 
C.W. Burfle
 
 
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July 24, 2012 7:26 PM

Get some resettable circuit breakers for 6, 8 or 10 amp like the one shown below.  Littlefuse makes them.  Use one for each transformer output. 

 

I installed them on my control panel and wire a 12 to 18 volt bulb (behind a red lens) across the circuit breaker contacts so the bulb comes on when tripped.

 

 

The circuit breaker reset button and red indicator light are shown in the upper left hand corner of the control board below.

 

 

IMG_3149

 

Works for me.  It is the same circuit that is used on a Marx circuit breaker device that is wired in between the transformer and the wire to the center rail of the track.

 

Charlie

 
 
 
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