Adequate power for 773?

[lionelsoni]

The size of the wire and the size of the magnetic circuit, or "core".

Strictly speaking, a transformer doesn't have a power rating, which would be in watts (W).  Instead, it is rated for volt amperes (VA) to allow for the possibility that the load current and voltage are not perfectly in phase.  The odd VA unit is dimensionally identical to a watt (a joule per second), but is a reminder that some part of the "power" represented by the product of the RMS voltage and RMS current is no net power at all but just energy bouncing back and forth between the transformer and the load.

[stuartmit]

If two transformers have the same voltage range, what determines their different wattages? 

[fifedog]

Stuart - I hate for you to be disappointed. Hence, you should send me the 773 for "safe-keeping".

It's all about helping others.

[stuartmit]

Well. That's dissappounting! 

[lionelsoni]

If the transformer's highest voltage (19 volts for the SW) cannot run the locomotive, you need a transformer that puts out more voltage.  If the circuit breaker trips (and nothing is broken or mis-wired), you need a bigger transformer.

In my experience, the 773 needs more voltage than other locomotives.  I use Zs, which put out 25 volts.

[stuartmit]

Adequate power for 773?

I have an SW rated at 130Watts hooked up on several blocks of my layout. Drawing from the lower voltage throttle are about 10 of the 022 switches With their lit controllers.

the trackage is hooked up to the higher voltage throttle, I have a block of track with about a 4% grade, which isn't wonderful, but unavoidable.

I have a dual motor 2321?Fairbanks Morse locomotive which will pull three Madison cars up the grade with no particular problem, yet my 773 with the larger tender number 2426W struggles up the grade.

is the power source, while adequate for the Fairbanks Morse inadequate for the 773? Would I get better performance with a transformer rated at a higher wattage?

Does the locomotives motor require a certain minimum wattage, but then doesn't benefit any further if More is available?