Medical Equipment Electrical-Safety Testing: What Facilities Should Understand

Electrical-safety testing helps identify damaged protective-earth connections, excessive accessible current, physical defects, and other conditions that may affect the safe use of medical equipment. The appropriate tests and acceptable criteria depend on the equipment, manufacturer instructions, applicable standards, facility requirements, and test conditions.

What electrical-safety testing evaluates

At a high level, electrical-safety testing on a medical device may look at several aspects of the equipment, depending on how it is built and how it is used:

• Physical integrity of the enclosure and accessible parts
• Power cord, plug, strain-relief, and connector condition
• Protective-earth (grounding) continuity where applicable
• Enclosure or touch current where applicable
• Patient leakage current where applicable
• Applied-part testing where applicable
• Functional verification appropriate to the device
• Documentation of findings and corrective action

Why testing varies by device

Medical devices differ in construction, intended use, applied parts, power configuration, isolation, and manufacturer requirements. A test appropriate for one device may not apply to another. The governing test procedure for a specific piece of equipment should be established from the manufacturer's service information, the applicable standard and edition, and the facility's program.

Common test categories

The categories below describe the kinds of checks that may be performed. They are not a universal checklist, and the specific method, test condition (normal or single-fault), and acceptable value should be determined for the equipment being tested.

• Visual inspection of the device, cord, plug, and accessible parts
• Protective-earth or grounding-continuity testing
• Enclosure or touch-current measurement
• Patient leakage-current measurement
• Mains-on-applied-part testing where required
• Functional verification appropriate to the device

Understanding BF and CF applied parts

BF and CF describe levels of protection associated with particular applied parts. The classification should be confirmed from the equipment markings, manufacturer documentation, service information, and governing test procedure. The device name alone does not determine the classification of every applied part.

What a useful service record should show

A service record should make it clear what was inspected, how, and what the outcome was. Useful records typically include:

• Equipment identification (make, model, serial, asset ID)
• Inspection or test performed
• Test conditions where relevant
• Measured results where relevant
• Applicable evaluation criteria
• Findings
• Pass/fail or service outcome
• Corrective action
• Technician and date

What happens when equipment does not pass

When a test result or physical condition is unacceptable, practical next steps generally include:

• Remove or control the equipment from clinical use as appropriate
• Document the finding
• Troubleshoot or repair according to manufacturer guidance
• Retest when appropriate
• Record return to service, replacement, or retirement according to facility policy

A note on AAMI ES1

AAMI ES1 has played an important role in medical electrical-safety practice, but the applicable current test procedure and limits should be determined for the specific equipment and service context. AAMI ES1 should not be used as shorthand for every current electrical-safety requirement.

Learn more

For a more detailed overview, see the PBES resource: Medical equipment electrical-safety testing and applicable limits at /resources/aami-es1. Related PBES pages include /services/electrical-safety-inspections, /services/preventive-maintenance, and /quote.