This is a two pin, locking style connector with "AMP" molded into the front edge; there is also a "P". Material is nylon or similar and the pins are pushed in from the rear like Molex connectors. What is "unusual" is the D shaped profile of the "nose" - close but not compatible with other two pin connectors I can easily obtain :(
AMP/Tyco never got back to me and our usual distributors are clueless. We have a few thousand machines in service with 24 volt power supplies that use this connector (manufacturer of the power supplies is HIPRO - now under new ownership - also not communicating)
Have spent a week trawling through connector catalogs, waited a couple of weeks for Tyco and the power supply folks to get back to me... a bit frustrating.