Basic Electrical Safety

Risk of Fire or Burn

The risk of fire in electrical systems primarily results from two causes: 1) Excessive heat generation usually due to a fault, 2) Inadequate heat dissipation usually due to a fault. In both cases sufficient electrical energy must be present for a fault condition to manifest itself in fire risk.  Power levels of 240VA or greater are generally considered to have enough energy to present a fire risk if not adequately protected against. One important thing to observe is that risk of fire is driven by power levels, unlike risk of electric shock that is strictly a function of voltage levels.  If power is available to drive a fault, a fire can start even if voltage levels are low enough to protect against electric shock.

Risk of fire due to excessive heat generation can occur as a result of numerous different types of faults.  However, all of these different faults have one thing in common: that is, a component or subsystem generates more thermal energy than it was designed for and as a result the system’s capacity for heat dissipation is overwhelmed, causing a fire to start.