Did my MRC DualPower O27 fry my Lionel Big Boy?? FIXED!! Thanks!!

AMCDave posted:

Is the DuelPower O27 not suitable for more modern engines?? Thanks

 The Dual Power 270 and O27 have very ugly modified sine wave forms and are not friendly to modern sound & control systems, especially MTH.

The word is “DUAL” as in two of something.

A “DUEL” is two people shooting at each other.

OGR Webmaster posted:

The word is “DUAL” as in two of something.

A “DUEL” is two people shooting at each other.

Thanks for the English lesson....now if I can get a model train answer I'll be happy!!! 

PS...6 hours on my back under the layout wiring and I blow up my Big Boy.....duel and dual run together.....

ADCX Rob posted:

AMCDave posted:

Is the DuelPower O27 not suitable for more modern engines?? Thanks

 The Dual Power 270 and O27 have very ugly modified sine wave forms and are not friendly to modern sound & control systems, especially MTH.

It is a Lionel Bigboy according to the post.  The transformer should not have done this, unless the voltage can go very high above 18-19VAC. G

Tinplate Art posted:

A Z750 seems a little underpowered to run a big boy with electronics and a large can motor. A Z1000 would be more appropriate.

But that would not cause a short would it??? And just for testing the Z750 ran a Lionel scale PRR Turbine and MTH PS3 PRR 2-10-4 fine.....so the short is still my issue....trying to figure out what happened. thx

Check a phasing or other wiring issue where you have the problem. Try the train on a completely different section of track. The Bigboy is so long with the tender that it could be bridging a problem area that the other engine, or Bigboy by itself, does not.

Just an idea.

George

Thanks all....It  boils down to the BB tender.....everything else is working fine. So I'll open it up today at sometime. 

In the meantime......do I need to dump the DualPower transformer??? I used it for a while on my MTH loco-sound subway set w/o issues....now some say it's harmful to MTH.....confused.....

GGG posted:

ADCX Rob posted:

AMCDave posted:

Is the DuelPower O27 not suitable for more modern engines?? Thanks

 The Dual Power 270 and O27 have very ugly modified sine wave forms and are not friendly to modern sound & control systems, especially MTH.

It is a Lionel Bigboy according to the post.  The transformer should not have done this, unless the voltage can go very high above 18-19VAC. G

yes, my thought, also.

Dave, can the MRC transformer exceed 18 volts? That's not good for TMMC/Legacy. 18 volt limit with a little headroom. The Z750 can definitely output 20 volts.

Set the track voltage with a meter to 17-18.

Max throttle I get 16v AC but I had it set at 50% when this happened. 

thx

ALSO.......would a MTH Z-4000 be a good choice for conventional running of Lionel, WbB and MTH???  thx

AMCDave posted:

Max throttle I get 16v AC but I had it set at 50% when this happened. 

thx

TMCC/Legacy likes at least 14 volts - 17-18 volts is nice. So, I am not sure how you fried it, unless it was with the Z750 voltage at max throttle. Also, if your meter is not True RMS - 16 volts is actually higher. I have a chart somewhere, but figure 16 is ~18-19 True RMS.

I do not think this is transformer related.  If the tender only is shorting, something happen inside tender.  Could be an exposed wire off pickup, or maybe a board short.  Lots of Red Herrings being thrown out here.  G

Sorry to hear about your troubles. I have used a Z4000 to run everything from prewar STD Ga to modern TMCC and DCS. Never had a problem. I run conventional most of the time. I've had two for almost ten years and will buy a couple more next summer for my rebuild.

Bob

I just had a caboose with a dead short.  The copper wiper somehow was not in line with the axel, but on a diagonal and when the roller pickup for the power was depressed by the track, a dead short occurred between it and the copper axel wiper.  Easy fix and easy to see the problem.  

When in a duel with an axel, it may be handy to remember there may be dual axles.  

Best of luck with your issue.  Hoping here it is something simple.

I have used MRC DualPower O27 "transformers" for many years and have never had a problem with any of my Legacy engines. They do not output a sine wave but the Legacy system does not care. The maximum voltage output is about 16V. Based on my experience with the DualPower O27 I doubt that is the cause of the failure.

So far I have failed one TMCC/RS5 circuit board, It happened with a ZW-L set at 13.5V. The failed circuit board is an ERR board in a converted American Models Northern. That tender now creates a short circuit if placed on the layout, it needs to be fixed.

AmFlyer posted:

... The maximum voltage output is about 16V. Based on my experience with the DualPower O27 I doubt that is the cause of the failure...

AMCDave posted:

...but I had it set at 50% when this happened.

 And therein lies the problem.

The MRC units are fine when used at full throttle settings as the sine wave is clipped very little if at all. At partial settings is where it gets ugly.

This isn't native to just MRC, any of the phase controlled power supplies at less than full output are prone to give unpredictable performance or results, especially when the AC is to be further modified on-board a locomotive for speed setting & control.

As stated above MRC O27 does not put out a sine wave. Only the MRC Pure Power units do. The Z4000 is perfect for conventional running, esp with the remote attachment! I am using it now on my Christmas Layout!

Well good news....I opened up the Lionel Big Boy tender and found a loose screw on one of the boards. Removed it....put her back together and all is well. Were it came from.....not sure....but the drag race start must have bumped it from where ever it was onto the board.

Ruining well with the MTH Z750 power anyway.....now I'm gun shy to connect the MRC pack back up!!! So I ordered a Z 4000 from Mario's trains and it's already half way here!!! The MRC may end up as a lighting power supp;y.

THANKS to all for the input. 

Dave:  Two good moves in one day!  Finding the loose screw and ordering the Z4000 from Mario.  Actually, that makes it THREE good moves.  You won't be disappointed with the Z4000.  Mario (and Joe his son) have always come through for me with fast shipping, great service and good prices too.

That is a huge relief!! Glad it worked out okay. 

Bob Severin posted:

Dave:  Two good moves in one day!  Finding the loose screw and ordering the Z4000 from Mario.  Actually, that makes it THREE good moves.  You won't be disappointed with the Z4000.  Mario (and Joe his son) have always come through for me with fast shipping, great service and good prices too.

My last new loco came from Mario's Trains. A MTH PRR 2-10-4 PS3.

My Z-4000 is on it's way landing Friday morning!! Mario's is always good. 

Sure feels good when you get things back up and running doesn't it?Nick

I was sweating the Big Boy being fried!! It's one of my favorites and didn't want to gut it and start over. Running it tonight after it was fixed was great!!! Thanks

I ordered my MTH Z-4000 12/27 late in the day. It landed at my door this morning at 10:30 AM!!! WOW.....Thanks Mario's Trains! Well packed in triple box with peanuts.  Don't think I'll try and get it downstairs alone....have my son come by and carry it!  Again thanks all!!!!