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equipment-service

System Evacuation (Vacuum Pump)

Always tested on the EPA 608

Pull a deep vacuum before charging a new or opened system.

About this skill

System evacuation to 500 microns (or 200 microns for hermetic systems), holding for 15 to 30 minutes to dehydrate, and verifying the vacuum holds before charging.

10 total steps
4 critical steps
Time limit: 30 min

What graders are watching for

  • 1
    Pull to 500 microns for standard systems
  • 2
    Hold for 15 to 30 minutes for dehydration
  • 3
    A rise in pressure during isolation indicates a leak or moisture

Common mistakes (and how to avoid them)

  • !
    Stopping the vacuum too early (leaves moisture in the system)
  • !
    Not verifying the vacuum holds (skips leak test)
  • !
    Using a single-stage pump on hermetic systems (need two-stage)

Practice this skill step-by-step

The static walkthrough above is the marketing overview. The full step-by-step interactive practice (with critical-step highlighting, per-step "why this matters" rationale, and what graders watch for on each individual step) is unlocked with a subscription.

View pricingTry 10 practice questions

Related equipment service skills

Dehydration of Wet Systems
Remove moisture from a system contaminated with water.
Charging by Weight (Cylinder Method)
Charge a system with refrigerant using the cylinder-and-scale method.
Major Component Replacement
Replace a compressor, coil, metering device, or reversing valve.