Lionel ZW-C Legacy/Conventional Operation Channel CU always on.

So with all the powerhouses unplugged there is no voltage anywhere correct?

What happens as you plug one PH in A, B, C, D and check? No voltage until the "C" PH is plugged in?

Can you raise and lower any/all the voltages? Or only A, B, and D voltages?

So with all the powerhouses unplugged there is no voltage anywhere correct?  This is correct.

What happens as you plug one PH in A, B, C, D and check? No voltage until the "C" PH is plugged in?  When I plug in one PH at a time I get 18v on channel 3 CU as the power supply gets plugged in to BU.

I can raise and lower voltages on all other channels but 3/CU.  This channel is a constant 18v.

Thank you!

George

Did you try a recalibration? You can find the process in the instructions.

George

gmach5 posted:

So with all the powerhouses unplugged there is no voltage anywhere correct?  This is correct.

What happens as you plug one PH in A, B, C, D and check? No voltage until the "C" PH is plugged in?  When I plug in one PH at a time I get 18v on channel 3 CU as the power supply gets plugged in to BU.

 

I can raise and lower voltages on all other channels but 3/CU.  This channel is a constant 18v.

 

Thank you!

George

 

That's a good clue, now we need a schematic.

Schematic for ZW-C transformer is in the attached PDF. See page 7 of the PDF figure 6A.

You might want to check the ZW-C in conventional mode to see how "C" operates. To do this turn off the command base. From your post it sounds like you're running the ZW-C in command mode with the legacy command base. Also try a different one of your 180 watt transformers in "B" to see if it responds the same way. Some of the 180 watt transformers have the phasing reversed.

Here's the attachment.

OK.  I tried the transformer in conventional mode (turned the Legacy base off and turned on the ZW C) and there is still a constant 18v coming out from channel 3 or CU.  I have tried all 4 PH 180W power supplies and as soon as I plug one of the power supplies into BU-CU gets 18v.  It's acting like there is a jumper in the molex plug on the transformer but I can assure you there is not.  I am checking the pins that come out of the ZW. 

I performed a reset of the ZW C.  I held in the program button while powering on the transformer.  The lights flashed 5 times and then stopped.  Still, there is 18v on channel 3 or CU.

Thank you!
George

Great detective work George.

Can you get an image of where the jumper goes? Sounds like either externally or internally something is jumping the two.

A plug that shorts an input together in order to skip a powerhouse gets inserted into an input. This “short” doesn’t sound like that. This sounds like a shorted triac device.

Something else to try and see if it's a short is the opposite, If you plug the PH-180 into CU does BU now have power?

cjack posted:

A plug that shorts an input together in order to skip a powerhouse gets inserted into an input. This “short” doesn’t sound like that. This sounds like a shorted triac device.

I agree. The plug allows power to go from one channel to the other, but the handle still controls the voltage. Have we ruled out the Pot (potentiometer)? It could definitely be the triac for that channel as well.

George