berthapegues Posted February 8, 2010 Report Share Posted February 8, 2010 Why do buses need fast idle and/or require fast idle for wheelchair lifts ? Quote Link to comment Share on other sites More sharing options...
berthapegues Posted March 20, 2010 Author Report Share Posted March 20, 2010 can someone answer this forum please ? Quote Link to comment Share on other sites More sharing options...
speedracer1407 Posted March 23, 2010 Report Share Posted March 23, 2010 I can't speak for the specific operation of CTA equipment, but generally speaking, fast idle is needed to power heavy-duty accessories like, say, a wheelchair lift. As far as I know, most wheel chair lifts (the kind that actually lift the wheelchair and its occupant up to bus-level, are hydraulically powered. The hydraulic system is powered by a power take off (PTO), which is a geared shaft usually connected to the engine near the flywheel or to the transmission. This shaft drives the hydraulic pumps that pressurize the system. To feed the hydraulic system with enough pressure during high-load usage, the engine must run at a higher idle (fast idle) than normal to spin the PTO shaft fast enough and/or with enough force. Hope that helps. Quote Link to comment Share on other sites More sharing options...
Guest Posted March 23, 2010 Report Share Posted March 23, 2010 I can't speak for the specific operation of CTA equipment, but generally speaking, fast idle is needed to power heavy-duty accessories like, say, a wheelchair lift. As far as I know, most wheel chair lifts (the kind that actually lift the wheelchair and its occupant up to bus-level, are hydraulically powered. The hydraulic system is powered by a power take off (PTO), which is a geared shaft usually connected to the engine near the flywheel or to the transmission. This shaft drives the hydraulic pumps that pressurize the system. To feed the hydraulic system with enough pressure during high-load usage, the engine must run at a higher idle (fast idle) than normal to spin the PTO shaft fast enough and/or with enough force. Hope that helps. We use high idle on our fire trucks to help in operating the main ladder. Quote Link to comment Share on other sites More sharing options...
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