Energy Type Reference
A full list of the energy types currently supported by the system, including what they mean, units, and where they are commonly used.
How to choose the correct energy type
Choose the energy type that best describes the source being isolated, not just the machine itself. For example, a hydraulic press may require Electric-AC for the power disconnect and Chemical-Hydraulic for the pressurized fluid circuit. Multiple steps can exist in the same procedure if the equipment contains multiple hazards.
Tips
- If two hazards are isolated differently, create two separate steps.
- Use the listed unit to help standardize your energy-level entry.
- Keep energy naming consistent across similar machines so reporting stays clean.
Prefix and unit behavior
Each energy type has a prefix and a default measurement unit. Prefixes help categorize the energy family while units tell the technician what measurement is expected in the field. Examples include Volts AC, PSI, °F, InHg, and Roentgen.
Energy type decision flowchart
Use this quick guide to identify which energy type applies:
- Is there electricity powering the equipment? → Electric-AC (for wall/panel power) or Electric-DC Battery (for battery/UPS systems).
- Is there pressurized fluid that moves cylinders or motors? → Chemical-Hydraulic.
- Is there compressed air or gas driving actuators? → Compressed Gas-Pneumatic (plant air) or Compressed Gas (bottled gas).
- Is there fuel feeding a burner, engine, or heater? → Chemical-Fuel Gas (gas lines) or Chemical-Fuel Liquid (diesel, fuel oil).
- Are there moving parts that could crush, cut, or entangle? → Mechanical-Moving Parts and Nip Points.
- Is there a suspended or elevated load that could fall? → Mechanical-Gravity.
- Is there a spring, counterbalance, or stored mechanical tension? → Mechanical-Spring or Stored Energy.
- Is there hot water, steam, or cold water in the system? → Water-Hot, Temperature-Steam, Water-Cold, or general Water.
- Is there a vacuum system holding parts or product? → Compressed Gas-Vacuum.
- Is there a radiation source? → Radiation.
- Are there general chemicals, process fluids, or cleaning agents? → Chemical.
If the equipment has multiple hazards, create a separate procedure step for each one. Do not try to combine different energy types into a single step: isolation methods and verification differ between them.
Energy type quick reference
| Energy | Prefix | Unit | Typical use |
|---|---|---|---|
| Electric-AC | E- | Volts AC | Alternating current sources such as disconnects, breaker panels, motor starters, and drives. |
| Electric-DC Battery | E- | Volts DC | Direct current circuits and stored battery energy used in control systems, UPS units, and mobile equipment. |
| Chemical | C- | LBS | General chemical contents or process materials where exposure or release must be controlled before work starts. |
| Chemical-Fuel Gas | C- | PSI | Fuel gas lines and burners that require shutoff and verification before maintenance or service. |
| Chemical-Fuel Liquid | C- | LBS | Liquid fuels or combustible liquid systems that can feed equipment during service activity. |
| Chemical-Hydraulic | C- | PSI | Hydraulic circuits containing pressurized fluid, accumulators, or cylinders that must be relieved and blocked. |
| Compressed Gas | G- | PSI | Bulk or bottled compressed gas that may stay energized even after equipment power is removed. |
| Compressed Gas-Pneumatic | G- | PSI | Plant air systems that drive cylinders, valves, actuators, and other moving mechanisms. |
| Compressed Gas-Vacuum | G- | InHg | Vacuum systems that create suction or hold product, parts, or fixtures in place. |
| Mechanical-Gravity | M- | LBS | Suspended or elevated loads that can drop, shift, or fall if not blocked or secured. |
| Mechanical-Moving Parts and Nip Points | M- | LBS | Rotating, sliding, conveying, or pinching components that can move unexpectedly during service. |
| Mechanical-Spring or Stored Energy | M- | LBS | Stored mechanical tension or compression that remains after power is shut off. |
| Water-Cold | W- | °F | Cold water services that still require isolation to prevent flooding or flow into work areas. |
| Water-Hot | W- | °F | Hot water circuits with burn risk or system pressure that must be isolated before work. |
| Water | W- | °F | General water services where the exact operating temperature may vary by process or season. |
| Temperature-Steam | S- | °F | Steam and condensate systems with severe pressure and burn hazards that need positive isolation. |
| Radiation | R- | Roentgen | Radiation-producing or radioactive sources that require specialized controls and site-specific procedures. |
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