Safe Electrical System Design
Eliminate Shock Hazards
- Always be aware of the high risk of injury from power sources within equipment.
- Prevent free access to un-insulated electrical terminals or wiring.
- Equipment interlocks are required where hazardous voltages exist behind access panels or doors.
- Appropriate warning labels shall be installed on high-voltage equipment.
- The frames, enclosures, and other accessible metallic parts of all equipment must be grounded. Ground all large metal structures,
such as optical benches, that will hold electrical equipment to minimize personnel shock hazard.
- The conductor for grounding must be permanent and continuous.
- The conductor must be sized to present a sufficiently low impedance for all frequencies and fault-current conditions anticipated.
Eliminate Fire and Explosion Hazards
- Always be aware of the high risk of fire in equipment because of the presence of electrical power dissipating components and their connection to building power sources.
- Allow for adequate cooling or ventilation.
- Use proper fusing to isolate low-power circuits from line power.
- Temperature control systems shall employ an independent, hardwired, "over temperature" interlock to interrupt heater source power should the controller fail.
- Electrical wiring of LLE-built equipment shall conform to code. If uncertain about the proper design of prototype or wiring equipment configuration, consult the Electrical Safety Officer.
- High-pressure arc lamps and capacitors commonly used in laser equipment can present an explosion hazard. These items shall be enclosed in housing that can
withstand the maximum explosion pressure resulting from component disintegration.