Fan Railer wrote:MBTA1052 wrote:I'm just saying figuring I live around the MBTA and we have like 18 Screamers (F40s) that work off Inverter HEP that has dragged them into the ground and it's kind of hard to tell what throttle the engine is in when running in passenger service. Plus, I would figure it does get tiring to just hear the same sound for more than 20 minutes!!
last time i checked F40's don't use inverter HEP's; they use alternator driven HEP's, so they're prime movers are always running at notch 8 (900 rpm), unless they got rebuilt and i wasn't aware of it, but i doubt it. True inverter HEP units allow the prime mover to idle around notch 3 (480-620 rpm)...
Correct, and Metra was the first (and perhaps still the only) agency to order the -3S version of this unit. But the projected fuel savings was what drove the decision, although that really didn't pan out in the long run, due to the chronic driveshaft and main generator failures early on caused by excessive vibrations. So, they decided to rebuild them so that HEP is provided in notch 8, just like the screamers (F40's). Don't know if that's still ongoing or complete yet...
I expounded on this a while back, so here's a little
more if interested...