3AP1 DT-145
Circuit breaker 3AP1, 145 kV, 40 kA, stored-energy spring drive
3AP1 DT-145
- One self-compression SF6 interrupter unit per pole keeps the required drive energy low
- Patented stored-energy spring mechanism, identical in principle across the 3AP family up to 1,100 kV
- Three-pole operation on a common base frame with a single operating mechanism (FG); dead-tank (DT) build available
- Delivered fully pre-assembled and routine-tested; a single supervisor can install one breaker in about one and a half days
- First major maintenance after 25 years; temperature-compensated SF6 density monitoring as standard
Outdoor air-insulated substations145 kV network switching and protectionLow-temperature installations down to −50 °C (SF6/CF4 mixed gas)Compact substation layouts (DTC variant)
Sign in to see your price, availability and framework terms for 3AP1 DT-145.
Horizon-3 pattern: this exact page gains commerce powers on sign-in — the URL never changes.
SIMULATED · ASK-AN-EXPERT PILOT DEMO
Ask an expert about 3AP1 DT-145
15 minutes with the right switchgear specialist — question in, booked call out. No email archaeology.
Checking availability…
3AP1 DT-145 covers up to 145 kV of the circuit breakers range (≤ 800 kV across the category, √ scale).
Specifications
Main
| Product family | Siemens Energy 3AP1 high-voltage circuit breaker |
| Design | SF6-insulated, one interrupter unit per pole; built as live-tank (3AP1 FG, up to 245 kV) or dead-tank (3AP1 DT, up to 362 kV). SAP material numbers for this family carry the DT designation while order descriptions reference the FG arrangement |
| Pole arrangement | Three poles on common base frame with one common operating mechanism (FG configuration); single-pole operation variants available |
| Interrupter | One self-compression interrupter unit per pole |
| Operating mechanism | Stored-energy spring mechanism |
| Application | Outdoor air-insulated substations, 145 kV networks |
Electrical
| Rated voltage | 145 kV |
| Rated frequency | 50 / 60 Hz |
| Rated normal current | up to 3,150 A |
| Rated short-circuit breaking current | up to 40 kA (mixed-gas flyer 145/170 kV design); the 2022 catalog dead-tank table lists up to 63 kA short-time withstand for the 145 kV class |
| Rated lightning impulse withstand voltage | 650 kV (IEC, 145 kV); 750 kV for the combined 145/170 kV mixed-gas DT design |
| Rated power-frequency withstand voltage | 275 kV (IEC, 145 kV); 325 kV for the combined 145/170 kV mixed-gas DT design |
| Short-time withstand current / duration | 40 kA, 3 s |
| Rated peak withstand current | 108 kA (2.7 p.u.) |
Mechanical / environment
| Rated break time | 3 cycles |
| Ambient temperature | Standard SF6 designs to approx. −30 °C; −50 °C / −60 °C with SF6/CF4 mixed-gas variant (dead-tank version) |
| Maintenance interval | First major maintenance after 25 years |
| Gas monitoring | Temperature-compensated SF6 density monitoring with alarm and lockout levels; optional online monitoring (Sensgear) |
| Insulators | Porcelain or composite, variant-dependent |
| Transport and installation | Shipped fully pre-assembled and routine-tested (ratings up to 300 kV); installation approx. 1.5 days |
| Control | Basic or compact control variant; 19 auxiliary switch contacts, operations counter |
Standards & certifications
| Type tests | Type-tested in accordance with the latest IEC and ANSI standards (IEC 62271-100 governs high-voltage AC circuit breakers) |
| Routine tests | Every breaker routine-tested in the factory before delivery |
| Test laboratory | Lead-factory laboratory accredited to IEC 17025; part of PEHLA and member lab of the Short-Circuit Testing Liaison (STL) |
Electrical — IEC ratings, 145 kV column (2022 catalog, current online edition)
| Rated voltage | 145 kV |
| No. of interrupter units per pole | 1 |
| Rated short-duration power-frequency withstand voltage | 275 kV (dead-tank and live-tank tables) |
| Rated lightning impulse withstand voltage | 650 kV (dead-tank and live-tank tables) |
| Rated normal current | up to 3,150 A (dead-tank table) / up to 4,000 A (live-tank table) |
| Rated short-time withstand current (1 s – 3 s) | up to 63 kA (dead-tank table) / up to 40 kA (live-tank table) |
| Rated break time | 2 cycles or 3 cycles (dead-tank table) / 3 cycles (live-tank table) |
| Rated operating sequence | O-0.3 s-CO-3 min-CO or CO-15 s-CO |
| Rated frequency | 50 or 60 Hz |
| Temperature range | −60 up to +55 °C (catalog footnote: limited normal-current rating at more than +40 °C) |
| Maintenance after | 25 years |
Options & variants
"-1S" decoded conservatively as the single (1) common spring-drive configuration; "/40" in the SAP description read as the 40 kA rating. Material numbers embed "DT" (dead tank) while the free-text SAP description names the live-tank "3AP1 FG" — the 145 kV key ratings are identical in both source tables. Family total: 7,721 SAP order lines since 2015 (SAP E3501 counts, not independently re-verified in this review).
| SAP material / variant | Rated voltage | Breaking current | Rated current | Configuration | Order lines since 2015 |
|---|---|---|---|---|---|
| 3AP1DT-1S-145KV | 145 kV | 40 kA | up to 3,150 A | Three-pole, single common spring drive; SAP description "modelo 3AP1 FG-145kV" | 1,782 |
| 3AP1DT-1S (configurable KMAT) | 145 kV | 40 kA | up to 3,150 A | Configurable master material "INT. DE POTENCIA 3AP1DT-1S-145kV/40" | 617 |
Documents & downloads
Catalog High-Voltage Circuit Breakers from 72.5 kV up to 1,100 kV (Siemens Energy, 2022) (current online edition)
Flyer 3AP1 DT up to 170 kV with mixed gases for lowest temperature applications
Brochure High-voltage compact switchgear 3AP1 DTC for 145 kV and 245 kV
Also covered in the technical library
Brochure Maintenance of AIS 3A Circuit Breakers
Flyer Maintenance of AIS 3AP DT and DTC — Preventive Maintenance
Brochure Siemens Energy High Voltage Dead Tank Circuit Breakers — US Catalog
Ordered designations
Representative orderable type designations of this family — searchable via the catalog search.
Related products
3AP1 DT-245 Dead-tank circuit breaker 3AP1 DT, 245 kV, up to 63 kA, stored-energy spring drive
245 kV · up to 63 kA / 4,000 A · Dead tank, single-break interrupter Datasheet · Dimensions ↓ 3AP1 DT-362Dead-tank circuit breaker 3AP1 DT, 362 kV, up to 80 kA, 2-cycle, stored-energy spring drive
362 kV · up to 80 kA / 5,000 A · Dead tank, 2-cycle, single break to 63 kA Datasheet · Dimensions ↓ 3AP1 DT-72.5Dead-tank circuit breaker 3AP1 DT, 72.5 kV, up to 40 kA, stored-energy spring drive
72.5 kV · up to 40 kA / 3,500 A · Dead tank, single-break interrupter Datasheet · Dimensions ↓
3AP1 DTC-145