UL 1278 Figure 9.1 Hazardous Moving Parts Probe PA160

The UL 1278 Figure 9.1 PA160 Hazardous Moving Parts Probe is a precision safety instrument designed for portable electric tools including drills, grinders, and sanders. It is engineered to assess if hazardous moving elements such as gear trains, blade shafts, or motor rotors are inaccessible through tool guards or enclosure gaps. The probe features a durable stainless steel tip, narrow enough for tight tool crevices, and an insulating nylon handle to ensure tester safety, simulating accidental user contact.

Specifications:

• Probe Type: UL 1278 Figure 9.1 PA160 Hazardous Moving Parts Probe (for portable electric tools)
• Probe Material: Stainless steel (rigid, corrosion-resistant; withstands minor contact with moving parts)
• Handle Material: Nylon (fully insulating, heat-resistant up to 100°C; non-slip grip for controlled operation in tight tool spaces)
• Key Dimensions:
  • Total Length: 88.9 mm (3.5 inch)
  • Head Length: 25.4 mm (1 inch)
  • Head Radius: R3.2 mm (1/8 inch)
  • Former Head Diameter: 12.7 mm (1/2 inch)
  • Tail Diameter: 25.4 mm (1 inch)

Test Procedures:

1. Inspect the probe for damage such as bent tips or cracked handles to ensure structural integrity.
2. Power on the portable electric tool and activate its moving components like drill chucks or grinder wheels.
3. Hold the insulating handle and align the probe tip with gaps in tool guards or enclosures.
4. Apply a steady 10N thrust to the probe—stop immediately if resistance from moving parts is felt.
5. Check if the probe contacts rotating components or bypasses safety guards.
6. Record whether the tool meets safety requirements (pass/fail) and power off.

Applications:

• Safety testing of hand-held electric drills (chuck gears and motor shafts) per UL 1278 Figure 8.3.
• Verification of orbital sanders (pad drive mechanisms) to block access to moving parts for U.S. markets.
• Quality control for electric screwdrivers (gear trains) during manufacturing.
• Post-production audits of jigsaws (blade shafts and linkage parts) to meet UL 1278 safety standards.