Which 180 w power supply??

Yes, the new bricks “last 4months” were redisigned internaly but apparently function the same. 

The zw-l has 620 Watts, apparently due to listing restriction. 

Mine are probably 10 years old and have the red button.

Thanks for the reply. So which is which?

I noticed in Lionel's Power & Track catalog the brick by itself (6-22983) has a red button and the one without the red button is included with the CW-180 transformer 6-37947.

Just wondering.

I can only assume the black button ones are the newest...assuming that there aren’t two different ones. Although they may have different plugs and infact be not the same run of bricks.

i read somewhere that the newest one have a slightly slower trip time. I forget why, something about being too fast for the lockon device  trip time.

Check for a colored part number stamp on the bottom - that's a recent version

Do they have date codes like the cw80?

Here's one from eBay that is previous version - I'll dig one my spares out later and take a photo - Chesterfield, MI is a good clue

Yes, the code is molded in the case at the bottom re: out of phase production run - see attached