Standard Bus Procurement Guidelines - APTAStandards.com
Standard Bus Procurement Guidelines - APTAStandards.com
Standard Bus Procurement Guidelines - APTAStandards.com
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<strong>Standard</strong> <strong>Bus</strong> <strong>Procurement</strong> <strong>Guidelines</strong><br />
5.5.5 ELECTRICAL COMPONENTS<br />
All electrical <strong>com</strong>ponents, including switches, relays, flashers, and circuit breakers, shall be heavy-duty<br />
designs. These <strong>com</strong>ponents shall be longest lasting, <strong>com</strong>mercially available, designed to last the service<br />
life of the bus and shall be replaceable in less than 5 minutes by a 3M mechanic. Sockets of plug-in<br />
<strong>com</strong>ponents shall be polarized where required for proper function and the <strong>com</strong>ponents shall be positively<br />
retained. Any manually resettable circuit breakers critical to the operation of the bus shall be mounted in<br />
a location convenient to the driver and provide visible indication of open circuits. All electric motors,<br />
except cranking motors, shall be heavy-duty brushless type, with a constant duty rating of no less than<br />
20,000 hours. Electric motors shall be located for easy replacement and except for the cranking motor<br />
shall be replaceable in less than 15 minutes by a 3M mechanic. Electronic circuit protection for the<br />
cranking motor shall be provided to prevent engaging of the motor for more than 30 seconds at a time.<br />
5.5.6 MULTIPLEX WIRING SYSTEM<br />
The <strong>com</strong>ponents of the multiplex system shall be of modular design, thereby providing for ease of<br />
replacement by maintenance personnel. The modules shall be easily accessible for troubleshooting<br />
electrical failures and performing system maintenance. Each module shall be shielded to prevent<br />
interference by EMI and RFI; and shall utilize LEDs to indicate circuit integrity and assist in rapid<br />
circuit diagnostics and verification of the load and wiring integrity. Each circuit shall be capable of<br />
providing a current load of up to 10 Amperes. The internal controls shall be a solid state device,<br />
providing an extended service life. Wiring for data bus and node module power shall consist of three, 22<br />
gage or larger, UL approved, shielded, twisted pairs.<br />
Ten percent (10%) spare input and output shall be provided at t\each I/O location. Wiring used for the<br />
multiplexing shall be stamped with the address of the corresponding I/O location.<br />
Protection to each individual circuit shall be provided. An automatic test system, integral to the<br />
multiplexing, shall be provided. A single test button mounted on a panel at the driver’s <strong>com</strong>partment<br />
area, upon activation, will provide a system check of the circuits. Corresponding LED lights on the<br />
panel will indicate failure points. The system shall be hosted on an IBM-<strong>com</strong>patible personal <strong>com</strong>puter<br />
as well as a hand held field diagnostic unit capable of reading the network data, control function and<br />
address data, or function code. The mechanic shall be able to use either unit to check bus wire function.<br />
5.5.7 BATTERIES<br />
Batteries shall be easily accessible for inspection and serviceable only from outside the bus on the street<br />
side and shall be securely mounted on a tray. Batteries shall be of premium construction and shall be<br />
fitted with threaded stud terminals. Positive and negative terminals shall have different size studs, or the<br />
battery terminals and cables shall be arranged to prevent incorrect installation. Battery terminals shall be<br />
located for access in less than 30 seconds with jumper cables. No less than two conventional lead-acid<br />
Technical Specifications 192 10/18/07
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