Mixing 180 & 135 Bricks into TIU

You bet, no problem at all.  Make sure they're phased properly, that would apply to any configuration.

 Wouldn't there be an issue if you ran them all in fixed mode??

Probably not for power delivery.  It might be prudent to do an overload test, though, to see how the circuit breakers work/trip, although the TIU will probably react faster.

Why would it be an issue if one used the variable channels as variable?

The 180 bricks have super sensitive breakers. The newer TIUs after first edition have 20 amp fuses. The max input for a TIU channel is 18 volts @ 10 amps.

A lionel brick is an excellent power source for a TIU channel except for a super sensitive breaker.

Trust me.  The circuit protection in
the 180 watt bricks is microseconds. The breaker trips
before you know there's a problem.
It trips so fast it make locating the
problem difficult as the evidence is
eliminated by the super fast breaker. There's no sparks to give
any clue as to the cause.  You have to wire the layout so each
section is like a zone. That way you
can unplug zones and then turn the
power back on.  If that wasn't the zone with the problem, the breaker
has already tripped. As each zone is unplugged and the breaker does
not trip, you know where to start your visual inspection.

Even then, it can take quite some time to find a engine's broken roller
as there were no sparks since the
breaker was so fast.

Moke Mike

I've had no issues with the fast breakers on the PH180 bricks with the TIU.  I agree, they are fast, but I like that, it minimizes the possibility of further damage.  However, on a problem switch, I did see plenty of sparks before the breaker tripped.

 

I'd be more careful with the PH135 bricks, those breakers are not nearly as fast, and I'd probably opt for some 10A fuses in series with those bricks going to the TIU.

According to Barry, the TIU doesn't have overload protection, you're dependent on the breaker in the input transformer.

I realized after I posted we're talking MTH here.  The TIU has 20 amp fuse protection, a 135/180 combo is 17 amps, so if that is exceeded, the 180 will trip quickly, the 135 shortly thereafter, unable to carry anywhere near a 17 amp load for any duration.  This might actually appease those that had concerns with the 180 tripping too fast.

 John,

 

Aren't the 20 amp fuses in the TIU the overload protection?

What am I missing?

 

Thanks, Greg

Never owned a 135 brick so I can not speak for them. The 180 can have a cow catcher tap the center rail and the breaker trips. Too me a little to much protection.

 

After the first run of TIUs they all come with 20amp fuses. 1 for each channel. Minimal protection but protection. I see it as a 2nd tier of defense in case the transformer breaker fails.

John,

According to Barry, the TIU doesn't have overload protection, you're dependent on the breaker in the input transformer.

That's incorrect.

 

 

 

 

 

Greg,

Aren't the 20 amp fuses in the TIU the overload protection?

What am I missing?

Every TIU except for the original, Rev. G, has 20 amp internal fuse protection. You're not missing anything!

 

In addition, each channel has TVS protection, as well.

 but I did say fixed mode??? i WANT MORE POWER!!!

I know the 20A fuses are there, but since the TIU channels are rated at a maximum of 10A...  I suspect there's a large window where you can overload the TIU and probably cook it without blowing the 20A fuses.

 

A TVS has nothing to do with overloading, it's strictly transient protection.

I agree,

There would be no issue if they were run in fixed or variable mode. There are 4 different channels running on 4 different bricks.

I do not know MTHs reasoning for putting in 20amp fuses. Maybe, the 18v 10amp max input is way underrated. It could be a marketing thing as there biggest transformer output is 18v 10 amps. Maybe,something to do with the UL stuff.

 

I have seen posts on this forum of guys combining bricks for 360 watts of power. They have reported no problems.

 

Anyway, there is no reason one can not change out the 20 amp automotive fuse and replace with a 10 or 15 amp fuse.

Given the fact that the NJ Hi-Railers report regularly toasting TIU's until they fan cooled them, I suspect that you can overload them without blowing the 20A fuses.  I'm planning on putting in 15A fuses, since it's no big deal to change them.  I don't know why they have the 20A ones in there.  Alternatively, I may just put the lower value fuses in-line with the TIU, makes them easier to change.  I personally don't feel the 20A fuses provide real overload protection.  The relays are rated at 10A on the fixed channels, and I'm sure the variable channels won't put up with 20A for long.

John (& Gregg),

I know the 20A fuses are there, but since the TIU channels are rated at a maximum of 10A...  I suspect there's a large window where you can overload the TIU and probably cook it without blowing the 20A fuses.

A TVS has nothing to do with overloading, it's strictly transient protection.

Where did I say that a TVS is overload protection?

Barry

He only stated TVS is not overload protection. He did not say you said it.

 

If I put 19 amps through a TIU channel and it becomes toast a 20 amp fuse is not overload protection.

 

Another thought about the 20 amp fuse is that maybe a channel can handle almost 20 amps peak but not continuous. 

Barry,

 

I'm certainly saying that an over-rated fuse is not overload protection, just as a penny in your fusebox is not overload protection.

 

Are you saying that the 20A fuse is all the protection you need on the transformer side and additional circuit protection there is unnecessary?  If so, we'll have to agree to disagree on that point.  If the TIU can't handle a sustained load of less than the fuse rating, then the fuse is oversized.

 

As far as the TVS, you're the one that introduced that into the discussion about overloads, I was just clarifying that has nothing to do with loading.  It's a good feature, but that's the same as saying the TIU has a serial port, doesn't apply to this discussion.

 

John,

Are you saying that the 20A fuse is all the protection you need on the transformer side and additional circuit protection there is unnecessary? 

Again, where did I state that? The actual fact of the matter is that the fuse protection in the TIU is there to protect the TIU itself against overloads, not the trains that it controls. That task falls to external devices. As to why MTH designed the protection that way, you'd have to ask MTH.

As far as the TVS, you're the one that introduced that into the discussion about overloads, I was just clarifying that has nothing to do with loading.  It's a good feature, but that's the same as saying the TIU has a serial port, doesn't apply to this discussion.

You're much to smart a guy to be acting as dense as you are. Information relating to additional methods of circuit protection is by no means out of place on this thread.

 

Regardless,your original statement:

According to Barry, the TIU doesn't have overload protection

was both incorrect and also attributed statements to me which were false.

There was a previous thread that  I incorrectly stated that the input transformer breaker doesn't actually protect the circuit and the TIU would shutdown before the transformer breaker.  However, I remembered it incorrectly, it was actual Dave Hikel that made the statement.

 

Barry, in spite of my incorrectly attributing the statement to you, the fact remains that that statement appears to be basically correct!  The TIU has no overload protection, other than the inadequate 20A fuse.  My point is that I don't believe the 20A fuse is sufficient to protect the TIU alone.

 

Thousands of TIU's in service seem to disagree with you John.  The number of TIU's that have failed due to overload since the fuses were added with Revision H1 is minuscule.  Of those that have failed, I am aware of none, including the NJ Hi-Railer's units, that were not caused by exceeding the 10 amp power supply rating.  Basically, you have to connect a power supply that will supply more than 10 amps continuously to kill one.  If you want to say that someone who doesn't read the instructions can kill a TIU, that would certainly be true.  Putting all 360 watts of a TPC 400 through a single TIU channel, as Jim alluded to, will cook it for sure.  Of course, you could say the same thing about someone who burns up their electric shaver by plugging it into a 240 volt outlet when traveling in Europe.  You can hardly fault MTH for such blatantly abusive behavior.

 

The TIU is a remarkably robust piece of hardware that will tolerate much abuse.  Far more abuse, in fact, than many locomotive decoders, motors, lights, etc.   The TIU does rely on external circuit protection as a first line of defense against a short circuit.  If you follow the instructions with your TIU and connect a power supply with no more than 10 amps capacity you'll be in good shape.  When a short circuit occurs the amperage draw will quickly exceed 20 amps.  If the power supply's circuit protection should fail the fuses will blow before any damage is done to the TIU.  All the TIU components will tolerate a 20 amp load for several seconds.

 

Would it be nice if MTH added 10 amp re-settable breakers to a future TIU revision?  Sure.  They've already used a six amp breaker on the DCS Commander.  However, to say that the TIU has no circuit protection is simply inaccurate.  You attempted to atribute such a claim to Barry.

 

According to Barry, the TIU doesn't have overload protection...

You have now attempted to attribute such a statement to me.

 

However, I remembered it incorrectly, it was actual Dave Hikel that made the statement.

 

You will note, John, that I did NOT say that the TIU has no circuit protection.  I only said that it relies on the transformer's circuit protection to disconnect track power before the fuse blows.   You are selectively ignoring my words....

 

The only way for the TIU to cut track power without blowing a fuse is if you press the E-Stop button. (emphasis added)

...in an attempted to defend an indefensible statement.  I make plenty of errors here on the forum and in the rest of daily life.  Mistakes happen.  Please don't try to pass your errors my way, I make enough on my own.

 

BTW, to the OP, John's original advice was quite correct and the thread could easily have ended there.  The 180 and 135 bricks can mixed (one brick per TIU channel) without trouble.  The only issue is correct phasing.  At least one production run of 135 watt bricks was wired out of phase at the factory with the 180 watt bricks.  It is prudent to check the phasing on any layout with multiple power supplies, and it's particularly good advice when working with Lionel 135 watt bricks.

Dave,

 

Thanks for sorting that out!

OK, a little poetic license was taken by me, I can agree there.  However, my original point actually was that you needed to depend on the transformer's circuit protection, or your own added circuit protection on the input side.

 

I guess the bottom line here is I'm a bit leery of the 20A protection, so all I really was trying to suggest is make sure you have input protection of your own.  My reasoning for the 135W bricks is I have seen those shorted by a derailment and although there was lots of heat, the breaker never tripped.  I won't connect those to my TIU without some additional fusing or a better circuit breaker.

 

Clearly, I agree with checking the phasing for any mufti-transformer configuration, especially if they're all going to TIU channels.

 

Peace!  I think this horse has truly been beaten to death.  It's just unfortunate that I was riding at the time.