Sorry for having to correct your terminology, but if it has 3 positions, it's not a Y, it's a 3-way. A Y turnout has only two positions, and the Peco switch motor would be an exact fit.
Because you reference code 80 rail, are you speaking of N-scale? In HO scale, the Peco products are code 70, 83, or 100 rail.
We have a couple of the Peco 3-way code 100 turnouts on our HO scale club layout, but they are not powered. A Peco 3-way turnout has two throw bars that seem to be too closely spaced to use two separate Peco motors, but maybe Peco makes a special dual motor for them.
A quick perusal of the Cherry Creek Hobbies web site in Torrington, Wyoming, who sells Peco HO scale track, tends to indicate that Peco does not have an HO scale 3-way turnout in code 83, but only code 100 -- and there's no special motor listed for use with the 3-way turnout. cchobbiies does not carry Peco N-scale track.
http://www.cchobbies.com/track/peco.htm
Peco's web site in England does not list a 3-way N-scale turnout as being one of their products, so you apparently have a plain Y, which the regular Peco motor would fit onto.
http://www.peco-uk.com/Products/pecoproducts.htm#Zgauge
It takes an iron man to play with a toy iron horse.