transformer wiring question

[RichDS]

In my 12x16 post-war layout, I have a ZW transformer with a common ground for the layout. Power is supplied to the track and to the fixed voltage plugs on the turn-outs(022 switches) from this transformer.

I also want to hook up a KW transformer to the same layout to use for accessories. 

Can I use the same common ground that is conneccted to the ZW? or is another common ground needed for the KW transformer?

Do both transformers need to be somehow connected to each other?

THANKS!

[lionelsoni]

The two transformers' commons (terminals U of both transformers) need to be connected together, but only if you are powering 022-type turnouts or other accessories, like crossing gates or block signals, that connect to the track.

(There are no "grounds" involved.  You can ground the transformer commons if you want to, but you won't see any effect from that.)

You will probably see well-meant advice to "phase" the transformers.  That is not necessary.  In fact, there is some good reason to have the accessory transformer out-of-phase with the track transformer.

[trainlivebob]

I was using a KW for accessories and did not like it because it does not have a 14V post.  You achieve 14V with a 20V and 6V post differential.

Thus when using accessories to the track with isolated tracks as switches, they would get 20V since I was using the track common at 0V.

When using it directly to an accessory it was OK.  But I ended up getting a LW that has 14V post to ground.

[lionelsoni]

You can also simply use one of the variable outputs (A-U or B-U) set to 14 volts, or whatever you need, for accessories.

[ADCX Rob]

The KW is a great accessory transformer if you are not also running trains with it as it has 2 variable & 3 fixed ranges to work with.

[trainlivebob]

ADCX Rob

The KW is a great accessory transformer if you are not also running trains with it as it has 2 variable & 3 fixed ranges to work with.

 

True,

I was using the variables for some sidings and a loop.

[BigAl 956]

The Lionel KW and ZW will operate together if you tie the U terminals together but it gets funky with accessories because the KW splits a lot of voltages off in seperate circuits.

I used my ZWs inner B or C controls for switches and lights. If you want to have a common ground return then the U terminals need to be tied together and the transformers phased, wich basically means the line cords on both transformers need to be oriented the same way.

One thing to considder is the switches and controller eat up a lot of watts. I converted my controller and switch lamps to LEDs to reduce the wattage and heat.