Spring Conference La Jolla, CA - March 2016 Electrical Wiring & Fire Safety Presentation Grant Hendrick – First Transit Dir. of Maintenance

Wiring Focal Points When Performing Your Fleet Maintenance Begins with good vehicle spec’s and equipment selection – (options such as alternator output, number of batteries, and fire suppression consideration). PM (preventive maintenance) means just that; prevent problems, (do good PM’s). Inspection integrity is key, begin with a good check off sheet and insp. process. Focus on the following areas when performing your electrical wiring fire inspections Electrical Systems 2. Exhaust Systems 3. Oil, Fuel, and Fluid System leaks 4. Drive Belt Systems 5. Vehicle Cleanliness

Things to keep in mind when performing your wiring inspections Electrical wiring inspection refers to both visual and physical inspection without the disassembly of components. Inspect also means measuring key components for “heat potential” and “voltage drop”. Use a good infrared thermometer for spot measurements and use it properly (e.g. Cornwell MCL 52224). Make sure the “spot” to be measured is the required spot size to get correct, accurate, values. Check your device. Don’t forget to examine any ancillary equipment such as fare boxes, CCTV, PA’s, GPS, Radios, etc. (Some of these may have been installed post vehicle delivery).

Basic Voltage Drop Test A voltage drop test is an effective way to find excessive resistance in high amperage circuits. It's a quick and easy test that doesn't require any component disassembly Illustrates whether or not you've got a good connection Create a load in the circuit that's being tested. Then you use a digital volt meter (DVM) to measure the voltage drop across the live connection while it is under the load. Voltage always follows the path of least resistance, too much resistance causes voltage to flow through the DVM and create a voltage reading.

Basic Voltage Drop Test

Basic Voltage Drop Test continued If a connection is good, you should find little or no voltage drop See less than 0.4 volts for most connections, and ideally less than 0.1 volts. If you find more than a few tenths of a voltage drop across a connection, it indicates excessive resistance and a need for cleaning or repair.

Thermal Spot Measurements – Distance/Spot ratio (D/S ratio) – (check your specific device)

Electrical Wiring Focal Points 1. Electrical Systems – battery cables, routing, security, and terminations Don’t forget to check all grounding cables as well

Electrical Wiring Focal Points 1. Electrical Systems – battery box, alt and starter cabling, and ground cables for routing/security.

Electrical Wiring Focal Points 1. Electrical Systems – other wiring within electrical panels or under hood and body When inspecting wires check for signs of heat hardening, cracking, or stiffness (especially smaller gauge wiring). Examine for signs of overheated insulation or terminals. Use your thermal gun to check temps with circuits live or operational.

Electrical Wiring Focal Points 1. Electrical Systems – other wiring within electrical panels or under hood and body

Don’t forget to make sure all grease shields are in place and secure. Examine for deterioration or damage to any body mounted heat shields or thermal blanketing. Check that all exhaust mounting hardware is in place and properly secured. Ensure the exhaust cannot contact sensitive or critical areas if any movement occurs. Pay particular attention and examine turbo-charger to manifold connections for leaks. Oil or fuel contamination in or near exhaust area. Fire Prevention Focal Points 2. Exhaust Systems – pipe and tubing integrity, check for leaks at critical locations

Loose or missing “P” clamps could be a potential spot for rubbing and chaffing of fuel lines or oil lines. Don’t forget to examine transmissions for leaks from lines as well as gaskets. Fuel pump and fuel tank leaks at lines or tank. Do not forget A/C refrigerant lines – these also contain flammable fluids when under high pressure. Vaporization caused by high pressure leaks renders almost any fluid on a vehicle combustible. (Particularly in the vicinity of hot turbo-chargers or exhaust components). Fire Prevention Focal Points 3. Oil, Fuel or Fluid System Leaks. Check for any leaks at critical locations, or tubing damage

Fire Prevention Focal Points 3. Oil, Fuel, or Fluid System Leaks. Check for any leaks at critical locations, or tubing damage

Fire Prevention Focal Points 3. Oil, Fuel or Fluid System Leaks. Check for any leaks at critical locations, or tubing damage

Under hood temperatures on today’s body on chassis vehicles can reach temps in excess of 400 deg. F. Extremely close proximity of components under the hood help to contain the heat. Belt slippage or pulley bearing roughness could cause overheating and adds to the potential for belt failure, bearing seizure, and increased fire risks. Regularly checking pulley bearings for roughness or signs of seizure during your PM inspections is a key. Drivers should never operate a vehicle with a squealing belt. Shut it off right away to examine cause! Fire Prevention Focal Points 4. Drive Belt Systems - Check for alignment, pulley and bearing roughness, or overheating.

Fire Prevention Focal Points Result of belt slippage from a tensioner pulley bearing failure – this was a total vehicle loss!

Fire Prevention Focal Points 4. Drive Belt Systems – A/C compressor clutch bearing roughness resulting in overheating.

Fire Prevention Focal Points 4. Drive Belt Systems - Check for alignment, pulley and bearing roughness, or overheating.

These potentially flammable materials could come into contact with any overheating electrical components Fire Prevention Focal Points 5. Vehicle Cleanliness – Litter or combustibles in drivers area around electrical panel boxes

Ensure any non-OEM added electrical circuits are protected with their own fuse or circuit breakers. Review California Title 13 – Chapter 6.5, Article 8, Section Wiring section for more detailed requirements. It reads in part... (b) Wiring Protection... Wiring shall be properly supported and located so as to avoid becoming charred, overheated, or enmeshed in moving parts. Insofar as is practical, wiring shall not be adjacent to any part of the fuel system. Unless the wiring is metal covered, the edges of all holes in metal through which the wiring passes shall be rolled or bushed with a grommet of rubber or other suitable material. Fire Prevention Focal Points Proper electrical circuit protection is also the law in California

Diagram illustrating additional breaker protection by working with the vendor... creating added protection Electrical Wiring Focal Points Prevention is the key – work with your vendors if you see trends that cause concern

Obtain the appropriate tooling for making and repairing any electrical connections; –Avoid “crimp type” connectors, solder your connections –Use shrink tube to properly insulate connections after soldering Ensure techs know how to properly test for bad connections using digital volt meters and can conduct voltage drop tests to detect high resistance circuits. Use a good infrared thermal temp gun to spot test components and use the voltage drop test. Develop a good inspection process and use a well constructed check-off sheet for consistent inspections to prevent incidents like this... ! Fire Prevention Focal Points Lastly, improve skills and tools for technicians to conduct good fire safety inspections

Good Electrical Wiring & Fire Prevention Focus Can Prevent These Maintenance Disasters!

Questions on anything you’ve seen today? Thank you for your attention.