SF6 Gas Quality

Also stated in

• Stated independently by FIST 3-16, section 9.8.3, page 84 (May 2024).
  Read the reference passage

  9.8.3 Fill Equipment SF6 Gas Compartment

  "It is very important to refill the equipment with clean, dry SF6 gas. The more impurities that are in the SF6 gas, the more hazardous by-products will be created. [Test the SF6 gas prior to filling the breaker. The gas must meet the recommended levels of impurities as shown in Table 9.1 for reclaimed SF6 gas or Table 9.2 for new gas.] [SF6 gas shall not be added to a gas insulated circuit breaker while the circuit breaker is energized.]"

  FIST 3-16, section 9.8.3, page 84, May 2024. Agency copy of FIST 3-16

  The current standard governs; this passage is a public-domain description of the practice dated May 2024.

• FIST 4-7, section 6.1.53.1, page 144 (August 2023).
  Read the reference passage

  6.1.53.1 Gas Pressure Test

  "Gas pressure and density testing verifies the correct amount of insulating gas, commonly SF6 is in the system at the correct pressure and density which ensures the circuit breaker interrupter will be able to properly quench and interrupt electrical current in the arc produced when the circuit breaker opens under load or fault. SF6 gas also plays an important role in the mechanical performance of the circuit breaker."

  FIST 4-7, section 6.1.53.1, page 144, August 2023. Agency copy of FIST 4-7

  The current standard governs; this passage is a public-domain description of the practice dated August 2023.

• Stated independently by FIST 3-16, section 8.3.1, page 68 (May 2024).
  Read the reference passage

  8.3.1 SF6 Gas Analysis

  "In-service is based on gas which has been sampled from a breaker which is still in-service. Reclaimed gas is a gas which has been filtered and dried and will be placed back in-service. When new gas is added to a breaker, wait 72 hours prior to performing a gas analysis."

  FIST 3-16, section 8.3.1, page 68, May 2024. Agency copy of FIST 3-16

  The current standard governs; this passage is a public-domain description of the practice dated May 2024.