Do I need a quicker circuit breaker?

a few months back, worked on a ZW for a buddy and

the original breaker was bad, so replaced it with one from

Radio Shack (cant remember the part number).

but to test it, hooked it up and ran a screw driver across

the two rails and SNAP the Radio Shack breaker went almost

before I had a chance to make contact, it was instant.

The built-in circuit breakers in larger postwar Lionel transformers are slow to trip. I always use external breakers to supplement the internal ones.

I experimented with various combos of circuit breakers until I found a good mix that shuts it down quickly but doesn't trip unnecessarily. For each of my two main circuits powered by my ZW, I have TVS on the terminals, marine 5amp breakers and 4 amp PTCs that trip at about 6.7amps. Redundancy is what I wanted, but generally, the marine breakers trip first (lower trip voltage). All depends on the loads you run at. I started with 10 amp breakers and then went to 7. I was concerned for my circuit boards by the delay in tripping those breakers. The PTCs don't trip fast ordinarily, but will if you run consists near their max. 

 

Roger

Thanks everyone.I more than likely will use a lower value circuit breaker.It was sparking for as long time and that really worried me.Luckly no damage.

I do mine this way.

 

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

 

The Circuit breaker protects the wire,the TVS protects engine electronics for voltage spikes.

 

Dale H

Thank Dale for the advice

I'm now powering my track using the Lionel PowerHouse 180 bricks.  They have the fastest breaker that I've seen, and are excellent protection.  They feed into the MTH TIU, so I get some TVS protection there. 

 

We use the same scheme for our modular club with the PH180.

Does anyone know if there is a quick blow resettable breaker.  I know quick blow fuses are the best but I'd rather not have to replace fuses.  I have TVS on the ZW outputs and around a few places on the layout.  I also use TPCs on the ZWs.   But it is still not clear to me that this a good solution.  I guess I am just wondering if there is a quick blow resettable device, preferrably a rocker type on/off.

 

Thanks,

Ed

There are magnetic breakers, but they tend to be pretty expensive.  They are very fast acting.

These work really well...

 

http://www.amhobby.com/product...s/powershield_x.html

 

http://www.amhobby.com/product...owershield_x_ac.html

Bryan,

 

I would go with a 7 amp breaker unless you need all 10 amps, as 7 is plenty of power for a diesel engine and set of freight cars.

You can buy some good quality breakers from www.mouserelectronics.com for very little money. A 7 or 8 amp breaker is plenty of power for most trains.

 

The old postwar ZW has an internal 15 amp breaker across the common side and you can almost weld with it. No individual breakers!

 

Lee Fritz

cjack,

 

Just recently ordered some of those and they arrived in the mailbox yesterday. They sounded like a really nice item for protection, and thought it might be nice to try. I plan on using TVS's also, as others in the forum have suggested.

 

We recently moved and are still in mass chaos, won't have a chance to use them for a while. Anything to watch out for with these? Any tips? Did you hook up any of the aux devices? Is this the only device(s) you have in your track power for protection?

 

 

I've been using Polyswitch resettable circuit breakers part# RUEF 400 for about 10 years. They trip when there's a derail or other short. Cost about 40 cents.

I'm glad those work for you Gary, but I would be concerned about the trip times listed for modern electronics.

 

This is from the RUEF 400 Data Sheet.

 

 

John,

I use them as well....along with my marine breakers. I know that the trip time says 12.7 sec., but the ones I use are very close to the amp loads that I run, so when I get a short, they trip very quickly. 

I know they're thermally operated but they seem to trip pretty quick. Maybe cause I usually run multiple trains at 4-6 amps so they're already near limit. Although I've pulled as much as 8-9 amps without them tripping even though they have a 4 amp rating. I'll have to do a test and actually time how long they take to trip.

Gary,

They aren't tripping because the trip amp for that one is 8. That's the size I use, but I think mine have a lower trip. I started out with 3s, but they would trip just running the consist a couple of loops. So, I'm close to the edge with the 4s, but they only trip for a derail. Plus.....I added those 5 amp Blue Sea breakers and they tend to go first. 

 

Roger

in addition to a good external breaker on each power district/throttle feed I agree with the suggestion for connecting a TVS  [Transient Voltage Supressor]. Your breaker will trip for current surges however a TVS will clamp the circuit board threatened voltage spikes which do not trip breakers. Connected right on the Hot binding posts, A.D, etc on your pw ZW. See fuzzy photo of  $.45 TVS on a ZW "A"/"U" posts..... 

Thanks to all for posting.I am going to make a copy of this forum posting.I can see it being very usefull down the road.

Oh,and thanks Dewey on the TVS's. I have those all over my layout .

Good magnetic breakers are in the $80-90 range. 

I have been very happy over time with the 180 POHO breakers which are quick. 

Dewey, the PH180 breakers are as good as any magnetic breaker.  They are electronically triggered and very fast.

 

Thanks for the info John. 

 

Superwarp1 posted a video of the PSX AC he has on his layout. You can watch the video here.

Thanks for the video and thread link. Just read it all and watched video, lots of good info there. Now have it saved for future reference. Can't wait to get the trains out again and try these out!

 

Thanks again!