I've been reading the instructions for the Lionel TPC 300/400 and it mentions that two seperate power sources can be connected to a single TPC. Does this mean that I could connect both sides of my MTH Z-4000 to a single TPC? Is each side of the Z-4000 considered a seperate power source?
I'm viewing each side of of the Z-4000 as you would a single Lionel PowerHouse.
Thanks for any info!
Original Post

I really don't know if that would work or not. The feature exists so that you can connect two identical power sources thru a TPC. That would be 2 PowerHouse 135 watt bricks or 2 PowerHouse 180 watt bricks. You can't mix and match them.


TCA, NMRA, PRRT&HS Modeling the PRR Panhandle Division between 1948-1957.

Well...I think you could connect 3 135 watt powerhouses to a 400 Watt TPC. Anything under the power limit of the TPC, so I don't see why any power source couldn't be connected as long as you follow the power rule.


As regards linking both sides[throttles]of your Z-4K to TPC, the answer is not a good idea. Only fixed voltage transformers such as a pair of 135 or the 180 Power Houses should be paralleled.
Difficult to set the voltage of both sides of the Z-4K exactly the same. Lou Kovach's Video to introduce the TPCs covered the proper Transformer/Controller linkage.

A&Y RY[NC's Southern/N&W connector].

I'm a bit confused. Here is a quote from page 3 of the TPC manual:
"Your TRANSFORMER or PowerHouse Supply will power both the TPC unit and the track to which it is connected. Keep in mind that you may power the TPC unit with TWO transformers if they are phase correctly"

I would assume both sides of the Z-4000 are in phase with each other...can't imagine they would be out of phase with each other.
I'd suspect Chuck is right about the three 135's connected to a TPC-400, I can't imagine why it would be any different than two of them or two 180's.
I'm not using PowerHouse's for my power...I'm using a MTH Z-4000 that splits it's 400 watts between two controllers. The TPC 400 "regulates power up to 400 watts" the quote is from the Lionel specs. Each side (throttle) of the Z-400 actually provides 180 watts to the track.
Maybe I need two TPC 300's...one for each side of the Z-4000.
You can successfully link a single TPC to a single AC transformer of any type. I have each of my 180 watt transformers, for each power district, linked to single TPC 4000s[not paralleled]. I run on Conventional and TMCC. The TPC enables me to operate engines in Conventional from the handheld Cab 1. It[the TPC] also provides many more speed steps enabling smoother start and run.

A&Y RY[NC's Southern/N&W connector].

So while the TPC will accept two transformers or outputs connected in parallel, the Z4000 two outputs cannot be connected together. Dale says there is a fault detected by the Z4000 if you try to do that.
Incidently, I have had my (new) ZW B and C outputs tied together for several years (fed by two PH 180s). The only thing that didn't work about it was trying to address channel 2 or channel 3 under command control to vary the voltage. Often, one address would vary both outputs but it varied as to which address would do it. Then maybe neither one would do it. A short on the track did shut down both outputs. I run command, so I didn't need to adjust them...just was trying it. Emergency shut down worked perfectly however.
I am running it separated now...feels better and I don't think I needed more than 10 amps anyway.


Rockyroad the wiring on the TPC's will allow you to plug in two bricks to one TPC. Someone has actually connected 3 135 watt bricks to one TPC400. While you can not connect both sides of a Z4000 to one TPC I have connected a 180 watt brick and one side of a Z4000 to our club TPC 400. You MUST make sure the power sources are in phase. The club has later 180 watt bricks and they were not in phase with the Z4000. Lionel made a plug for the outlet of the early 180 watt bricks that reversed the output phase. You can use these if you can find them, cut off the plug end and put a Moldex connector on with the correct phase OR reverse the 110V input wires inside the brick. I did the later BUT cannot recommend it if you are not completely comfortable wiring equipment. By the way the MTH Z4000 is not in phase with my Z500 set.


I have one block operating off my left handle and a another (seperate) block operating off my right handle. The loco's travel between the seperate blocks and at times the power in each block is not the same.
I also have a toggle switch that will allow me to operate both blocks from one handle...left or right. I have inadvertently had both handles feeding power to both blocks at the same time and the internal breaker did not activate. I do not run more than one train per block at the same time.
I guess to be on the safe side I should have one TPC for each handle...probably a TPC 300 on each side.
I have inadvertently had both handles feeding power to both blocks at the same time and the internal breaker did not activate.

If you have the outputs tied together, but at different output voltage, you create a circulating current within the secondary winding of the transformer, but this current does not flow through the breaker. That means that you can have a dangerous situation with no protection.

Chuck, how did you know which side was supplying the power on your new ZW when B and C are connected in parallel?
Originally posted by Dale Manquen:

...Chuck, how did you know which side was supplying the power on your new ZW when B and C are connected in parallel?

I really did not know. I have a Lionel meter on it, but the current readout is not accurate per output as you know. I was getting 75% of the total current reading from the B output which was connected to 2/3rds of the track feeds points. The C output was connected to the remaining 1/3 and showed about 25% of the total current. The common connection was thru the track with no blocks. So I had some resistance in series with both outputs to the loads (the trains). I did not originally intend to connect the two outputs together. I had intended to use the C output for the spurs which were all blocked from the main lines and individually switched on or off. I made a mistake under the table and included a couple of main line feeds. It seemed to be a non problem so I left it that way until just recently when I was messing around with the command control of the ZW. Both outputs were always set to max of about 18vac and read the same (two digit readout).
I'm wondering how the Z4000 responds when an engine is crossing a block. Where the two pickups on one engine are connecting the two separately powered blocks together.


F&G RY yes Dale is correct. I match the voltage and watch the current so both power supplies are loaded with about the same current draw. An ideal soultion which we also use is 2 180 watt bricks on one main line and the Z400 on the other main line. The club layout only needs more then 10 amps when someone, me, runs long passenger trains - 18-24 21" metal passenger cars.


Originally posted by brucefclark:
The club layout only needs more then 10 amps when someone, me, runs long passenger trains - 18-24 21" metal passenger cars.
Time to install LED lighting in those cars, that'll solve that problem. Smile
Likes (0)
OGR Publishing, Inc., 1310 Eastside Centre Ct, Suite 6, Mountain Home, AR 72653