# 30B transformer circuit breaker



## Tranz4mr (Sep 3, 2013)

I need to replace circuit breakers in an American Flyer 30B transformer. Any idea what amperage circuit breaker is correct. Original part is PA 13A051.
There is one on each handle plus a 3rd on the fixed output.
Any idea what amperage to replace them with?
Is there a parts dealer that sells the correct amperage replacement?


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## alaft61ri (Oct 11, 2019)

Htryed to see your attachment wouldnt go through.


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## Tranz4mr (Sep 3, 2013)

alaft61ri said:


> Htryed to see your attachment wouldnt go through.


Thanks. Fixed it I think.


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## alaft61ri (Oct 11, 2019)

Ok i have a 30 b 300w i have taking mine apart dont remember seeing that.
Good luck al


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## Tranz4mr (Sep 3, 2013)

There is an older version where the circuit breakers are on the back panel.


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## AmFlyer (Mar 16, 2012)

I have not seen those thermal auto resetting breakers on any vendors website. The 300B is about 225W net output. Were it mine I would use 8A replacements, which allows 140W/handle and will avoid nuisance tripping. The primary purpose of these breakers is to protect against short circuits such as when an engine runs into an open turnout. That would happen to me at least once every time I ran the trains, the reality with two rail systems. 
Interesting there are 3 breakers, the Factory Service Manual shows two and the part number is PA12A099. I do not recall seeing the amperage rating of the factory breakers.


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## Tranz4mr (Sep 3, 2013)

Older versions had only 2 breakers on the back panel PA12A099 as shown in the service manual. All the manuals I have don’t show latter versions.


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## mopac (Feb 24, 2011)

Those look like old type breakers. I would look into replacing them with modern breakers.
Modern breakers blow much quicker. I use a Lionel ZW for my AC trains. The original breaker took 10 seconds to blow. Thats a long time. The modern breaker in my ZW will blow in 2 seconds. I think mine is 10A. So 8A or 10A should work. My breaker will reset itself.
And has.


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## Tranz4mr (Sep 3, 2013)

I’m protecting post war trains so the goal is to replace them with new thermal breakers similar to the originals since the originals are shot. The problem is figuring out the correct size amperage wise so I don’t exceed the original design and smoke the core.

I’m leaning toward 10 amp Buss 22110-000 like I would use to replace a KW breaker except 2 of them.
KW’s actual continuous output is 140 watts at 20 volts 10 amps. Does that sound like a reasonable replacement?

In response to Mopac yes if I was protecting modern trains with electronics I would minimum add external 1.5KE33CA Zener diodes for spike protection. If money was no object I would install external DCC Specialties PSX-AC breakers for a ZW set to trip at the ZW spec of 15amps.


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## mopac (Feb 24, 2011)

Tranz4mr. give Doug Peck a call at Port Lines. They specialize in American Flyer parts.
Doug is a great guy and will try to help you. You have the original part number and they
may have them.

Mon- Thurs 2-5 PM EST 888-708-0782


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## Tranz4mr (Sep 3, 2013)

Thanks. So far that appears to be the best AF parts site that I’ve seen. I’ll give him a call when he’s available on Tuesday.
Hopefully he has info or something I can use.
Are there any other AF parts/repair sites?


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## AmFlyer (Mar 16, 2012)

I would use a 15A breaker on a 19B but not a 30B. For the 3 breaker 30B I would not use more than 10A breakers. In my years of running Gilbert trains the need for more than 8A on a single handle has never arisen in conventional operation. Command Control is of course a different story. On the dual control transformers the breakers were not sized to protect the transformer core from continuous overload, just to interrupt short circuits. Most of the Gilbert layouts I see are a rats nest of 16 and 18 gauge wiring underneath with amature splices and untaped connections. A 15A breaker feeding a setup like that concerns me. Even my ZW-L's are limited to 10A/handle. Without the current limiting circuits it has (I think Lionel calls them foldback circuits) I likely would have welded some engine wheels to the rail by now. Its always at a mispositioned turnout.


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## Tranz4mr (Sep 3, 2013)

So I did some testing on the three existing circuit breakers to see how many watts they would hold at before tripping. I loaded the right side up with 1.8 ohms of minimum 100 watt resistors. Used TRMS current and voltmeters and got the Right to hold just below tripping at 138 watts, L at 132 and fixed output at 142. Assuming that the fixed output had the least usage it looks like the circuit breakers are 140 watt so if I use the bussman 22110-000 rated at 14v 10amp I should be good. Further testing found the left breaker was breaking down when I did longer tests. Next I’ll replace only the left and See what happens


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## Tranz4mr (Sep 3, 2013)

So I replaced the left retested and it held at 148 watts, let it sit for 30 minutes. It tripped above that. Burnt my fingers on the 250 watt 1 ohm resistor. So I feel that the Bussman 14v 10 amp replacement for Lionel KW is close enough.


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## Tranz4mr (Sep 3, 2013)

I replaced the circuit breakers on both handles.
You can buy a bare bussman fuse with no metal bracket to mount it securely for $3 but the Lionel parts guys like ttender.com sell it with a bracket as part number 20-22 for $8.50.
I had to flatten out the “L” bracket, enlarge the hole and then slot it with a dremel.
Thanks for all of your input. 

Here is a photo.


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## AmFlyer (Mar 16, 2012)

Looks good!


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## alaft61ri (Oct 11, 2019)

Nice job


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