Apta (Draft) Specification For: 30-ft, 35-ft, 40-ft, 45-ft, 60-foot (articulated) Transit Buses
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10.1Engine coolingA sight glass to determine satisfactory engine coolant level shall be provided and shall be accessible by opening one of the engine compartment’s access doors. A spring-loaded, push-button type valve or lever shall be provided to safely release pressure or vacuum in the cooling system with both it and the water filler no more than +/- 60 in. above the ground. Both shall be accessible through the same access door. Default
The radiator and charge air cooler shall be of durable, corrosion-resistant construction with bolted-on removable tanks. Alternative The radiator and charge air cooler shall be of durable, corrosion-resistant construction with non-removable radiator headers. Default
No screen in front of radiator Alternative Screen in front of radiator The radiator input shall be protected by an easily cleanable screen designed to collect large debris. Radiators with a fin density greater than 12 fins per in. or a louvered slit design shall not be used. No heat-producing components or climate control system components shall be mounted between the engine cooling air intake aperture and the radiator. The radiator and charge air cooler shall be designed to withstand thermal fatigue and vibration associated with the installed configuration. The radiator and charge air cooler cores shall be easily cleaned (to include engine side core surface) with standard pressure-washing equipment. Default
The engine cooling system shall be equipped with a properly sized water filter with a spin-on element and an automatic system for releasing supplemental coolant additives as needed to replenish and maintain protection properties. Alternative
The engine cooling system shall be equipped with a properly sized water filter with a spin-on element. The filter shall not release or contain supplemental coolant additives. Default
Control and drive of the radiator and charge air cooler fan(s) shall be the contractor’s standard design. Alternative
Radiator and charge air cooler fan(s) shall be electrically driven and capable of automated reverse operations for periodic self-cleaning of the radiator and charge air cooler. Default
Mounting location of radiator and charge air cooler shall be the contractor’s standard design. Alternative
The lower edge of the radiator and charge air cooler core(s) shall be mounted at a height no less than 3 ft above street level to minimize core fouling caused by dirt, debris, leaves, etc. Default
The cooling fan shall be temperature controlled, allowing the engine to reach operating temperature quickly. 10.2Charge air coolingThe charge air cooling system also referred to as after-coolers or inter-coolers shall provide maximum air intake temperature reduction with minimal pressure loss. The charge air radiator shall be sized and positioned to meet engine manufacturer’s requirements. The charge air radiator shall not be stacked ahead of or behind the engine radiator and shall be positioned as close to the engine as possible unless integrated with the radiator. Air ducting and fittings shall be protected against heat sources and shall be configured to minimize restrictions and maintain sealing integrity. Alternative If roof mounted over vestibule area; the radiator, charge air cooler and oil cooler shall be stacked horizontally provided specified operating temperatures are maintained during the design operating profile at the temperature ranges outlined in the Design Operating Environment.
IP 11.Transmission (conventional powertrain)The transmission shall be multiple speed, automatic shift with torque converter, retarder and electronic controls. Gross input power, gross input torque and rated input speed shall be compatible with the engine. The transmission shall be designed to operate for not less than 300,000 miles on the design operating profile without replacement or major service. The transmission should be easily removable without disturbing the engine and accessible for service. The electronic controls shall be capable of transmitting and receiving electronic inputs and data from other drivetrain components and broadcasting that data to other vehicle systems. Communication between electronic drivetrain components and other vehicle systems shall be made using the communications networks. Electronic controls shall be compatible with either 12- or 24-volt power distribution, provide consistent shift quality and compensate for changing conditions such as variations in vehicle weight and engine power. Default A nominal brake pedal application of 6 to 10 psi shall be required by the driver to engage forward or reverse range from the neutral position to prevent sudden acceleration of the bus from a parked position. Alternative A nominal brake pedal application of 15 to 20 psi shall be required by the driver to engage forward or reverse range from the neutral position to prevent sudden acceleration of the bus from a parked position. The electronically controlled transmission shall have on-board diagnostic capabilities, be able to monitor functions, store and time stamp out-of-parameter conditions in memory, and communicate faults and vital conditions to service personnel. The transmission shall contain built-in protection software to guard against severe damage. The on-board diagnostic system shall trigger a visual alarm to the driver when the electronic control unit detects a malfunction. An electronic transmission fluid level monitoring and protection system shall be provided. Default A brake pedal application of 6 to 10 psi shall be required by the driver to engage forward or reverse range from the neutral position to prevent sudden acceleration of the bus from a parked position. Alternative A brake pedal application of 15 to 20 psi shall be required by the driver to engage forward or reverse range from the neutral position to prevent sudden acceleration of the bus from a parked position. Default
The transmission shall not incorporate an automatic neutral shift function. Alternative
The transmission shall automatically shift to neutral whenever the door brake interlock is applied for five minutes. The driver shall be required to apply the service brake to re-engage forward range. Alternative
The transmission, when in forward direction, shall automatically shift the transmission to neutral when the vehicle registers zero road speed, engine is idle and service brakes are applied. If the status of any one or more of the three signals changes, the transmission immediately and automatically resumes forward mode operation. Directory: swc swc -> Packet Tracer Configure Initial Router Settings (Instructor Version) Instructor Note swc -> Chapter 50 Aircraft swc -> Conservation Security Program swc -> Click on enter the exhibition swc -> Southwest Christian – Tinley Park Invitational Meet Boys Cross Country Race Friday, September 30, 2016 Cool and Cloudy – 60 Degrees swc -> Date: October 28 – December 5, 2003 Project Website swc -> Publication and presentation log swc -> Ncdmf chpp chapter Shell bottom Ecological Role and Functions Ecosystem enhancement swc -> Directions: use the map in Download 0.56 Mb. Share with your friends:
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