Multiple Energy Sources

Depending on the specific piece of equipment you are servicing or maintaining, there may be one source of energy to lockout/tagout, or there could be many sources of energy that must be isolated before beginning maintenance activities.

An example of a single source piece of equipment would be an electrically driven pump motor.

An example of a multi-source piece of equipment would be a large boiler that has gas, electrical, and pneumatic energy sources.

As you can see, it is generally easier to isolate the energy sources leading to single source piece of equipment when compared to a multi-source piece of equipment.