Brochure · EN — Grid Technologies Service brochure (2023) describing scheduled maintenance for Siemens Energy air-insulated 3A circuit breakers. It outlines the OEM-recommended four-step service scope — diagnostic testing, inspection, preventive maintenance and function testing (illustrated by the 20-year revision of a 3rd-generation 3AS breaker) — and gives the recommended maintenance timelines for all breaker generations from the H620/H8XX series through 3AR/3AS and 3AQ/3AT up to the current 3AP/3AV family, which needs only a visual check at 12 years and a revision at 25 years.
Circuit breakers are the central components of both AIS and GIS switchgear. They must open and close reliably, keep quenching performance consistent at rated and short-circuit currents even after many switching operations, and rely on high-performance, dependable operating mechanisms.
To keep meeting these requirements, Siemens Energy AIS circuit breakers need maintenance. Service experts monitor the equipment, increase its wear-and-tear reserve and can even improve its reliability. The scheduled maintenance concepts combine overhauls and condition assessments in a predefined system based on the manufacturer's recommendations, while remaining flexible enough to adapt to individual requirements — helping each customer choose an adequate, cost-effective solution. All services are supervised or performed by certified Siemens Energy specialists.
The OEM-recommended revision follows four steps, shown here for the 20-year revision of a 3rd-generation AIS 3AS breaker.
| Step | Scope |
|---|---|
| 1. Diagnostic test | SF6 filling & gas analysis; hydraulic oil |
| 2. Inspection | Rupture diaphragm; visual check of circuit breakers; control of contact system; leakage test |
| 3. Preventive maintenance | Replacement according to OEM recommendations; maintenance of operating mechanism; cleaning gas compartments; anti-corrosion protection |
| 4. Function test | Mechanical & electrical function test; test operation; hydraulic monitoring system; trip & close solenoids; safety valve |
The recommended service timeline depends on the breaker generation. Each lifecycle starts with commissioning (Comm), followed by periodic visual checks (VC), extended visual checks (EVC) and a full revision (REV). Newer generations need fewer interventions: the 5th/6th-generation 3AP and 3AV breakers require only a visual check at year 12 and a revision at year 25, compared with a 15-year revision for the earliest H-series units.
| Generation | Breaker types | Service sequence (lifetime in years) |
|---|---|---|
| 1st – 2nd | H620, H8XX series | Comm → VC (5) → VC (10) → REV (15) |
| 3rd | 3AR, 3AS | Comm → VC (5) → EVC (10) → VC (15) → REV (20) |
| 4th | 3AQ, 3AT | Comm → VC (5) → EVC (10) → VC (15) → REV (20) |
| 5th / 6th | 3AP, 3AV | Comm → VC (12) → REV (25) |
Procedures strictly follow the manufacturer's requirements, with a wide scope of measures that can be tailored to individual needs for an economical solution. Work is carried out by certified technicians using original spares, with fast execution — resulting in increased equipment reliability.
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