2 Service Preparation and System Isolation

Prepare the work area

Begin by identifying the appliance, refrigerant, circuit, service history, and manufacturer’s instructions. Confirm that the technician has the required qualifications and that the planned work follows applicable regulations and site procedures. In the United States, EPA Section 608 certification applies to technicians performing covered refrigerant work.

Assess electrical energy, pressure, hot or cold surfaces, refrigerant exposure, restricted ventilation, and ignition hazards when relevant to the refrigerant or site conditions. Review the refrigerant’s safety information. Stop and obtain qualified assistance if the refrigerant or hazards cannot be identified or controlled.

Keep the work area clear, stable, and accessible. Provide suitable ventilation, control access, and keep ignition sources away when required by the refrigerant’s properties and instructions. Wear eye, hand, and other protective equipment appropriate to the task.

Inspect and stage equipment

Use gauges, hoses, fittings, and service equipment that are compatible with the refrigerant and rated for the pressures involved. Inspect equipment for damage, and confirm that recovery equipment and cylinders are suitable for the refrigerant and intended use. Arrange equipment to avoid trip hazards and protect connections from dirt and damage.

Isolate hazardous energy

Follow the employer’s energy-control procedure. Notify affected workers, perform an orderly shutdown, and identify every energy source that could cause unexpected startup or release energy. For electrical isolation, use the designated disconnect or another energy-isolating device—not a control switch alone. Apply personal locks and tags as required by the procedure.

Prove electrical isolation using the approved test method. Account for stored energy, including capacitors, rotating parts, hot surfaces, and pressure trapped in refrigerant-circuit sections. Identify valves and other isolation points from equipment documentation where possible. A closed valve does not by itself establish that downstream work is safe; consider possible leakage, bypass paths, and pressure that could reaccumulate.

Address pressure before opening

Before opening a high- or very-high-pressure appliance, follow EPA’s applicable evacuation requirements and the manufacturer’s instructions. In the relevant service circumstances, EPA specifies evacuation to 0 psig before opening these appliances. This is a gauge-pressure reading; it does not mean that the system contains no refrigerant or that every isolated section is safe.

Use the required recovery procedure and verify the condition at the section to be opened. If leakage prevents the required evacuation, follow EPA’s applicable exception requirements and the employer’s safe-work procedure. Do not treat a leaking or pressurized section as safe to open.

Verify and maintain isolation

Before work begins, check that locks and tags are in place and that the intended equipment is isolated. Verify that electrical energy is controlled and that pressure has been addressed in the specific section to be serviced. Maintain isolation while work continues.

If testing requires temporary re-energization, clear people and tools and follow the prescribed testing sequence. Then de-energize and reapply isolation before resuming service.

For example, before servicing a high-pressure circuit, identify the refrigerant and circuit boundaries, stage compatible recovery equipment, shut down and lock out electrical supplies, and follow the applicable recovery and evacuation procedure. Do not rely on a control switch or closed service valve as proof that the equipment is safe to open.

• lockout/tagout