Medium-Voltage Metal-Clad Switchgear
Type GM38 (38 kV)
Medium-Voltage Metal-Clad Switchgear, Type GM38 (38 kV)
Description
Type GM38 metal-clad air-insulated switchgear can meet almost any switchgear application from 23 kV through 38 kV. The horizontal drawout vacuum circuit breakers occupy the lower cell with voltage transformers (VTs) or drawout fuses available in the upper cell. The lower cell may be used for auxiliaries, such as VTs, a control power transformer (CPT) or drawout fuses. Two types of outdoor housing are offered: non-walk-in and Shelter-Clad.
Features
Type GM38 switchgear features include:
- One-high construction
- Universal spare circuit breaker
- Designed for up to 50 full-fault interruptions
- Closed door racking
- Uses the latest developments in vacuum interrupter technology
- Horizontal drawout type 38-3AH3 vacuum circuit breaker with type 3AH3 operating mechanism
- Common type 3AH3 operator platform for all ratings
- Over 60,000 type 3AH3 operators produced since 1998
- Highly reliable vacuum interrupters-estimated MTTF over 57,000 years
- Three-cycle interrupting time (optional)
- Interlocks permit insertion of high rating vacuum circuit breaker into lower rated cell but not vice versa
- Front accessible circuit breaker operating mechanism for ease of maintenance
- Floor rollout circuit breaker in lower cell without a dolly
- Visible secondary disconnect
- Pair with Siemens protective relays to match any typical application
- Meets or exceeds the latest ANSI, IEEE and NEMA standards
- UL Listing available for 40 kA rating.
Technical Data
| Measured Parameter | Units | Circuit Breaker Type 38-3AH3-1500 [1] | Circuit Breaker Type 38-3AH3-31 [2] | Circuit Breaker Type 38-3AH3-40 [2] | ||
| General | Nominal Voltage Class | kV | 38.0 | 38.0 | 38.0 | |
| General | Nominal Three-Phase MVA Class | MVA | 1,500 | ---- | ---- | |
| Rated Values | Rated Voltage | Maximum Design Voltage (V) | kV rms | 38.0 | 38.0 | 38.0 |
| Rated Values | Rated Voltage | Voltage Range Factor (K) | ---- | 1.65 | 1.0 | 1.0 |
| Rated Values | Insulation Levels | Withstand Voltage Levels Power Frequency | kV rms | 80 | 80 | 80 |
| Rated Values | Insulation Levels | Withstand Voltage Levels Lightning Impulse (BIL) | kV peak | 150 | 150 | 150 |
| Rated Values | Rated Current | Continuous | A rms | 1,200, 2,000, 3,000FC [3] | 1,200, 2,000, 3,000FC [3] | 1,200, 2,000, 3,000FC [3] |
| Rated Values | Rated Current | Short-Circuit (At Rated Maximum Design Voltage) (I) | kA rms sym | 21 | 31.5 | 40 |
| Rated Values | Rated Current | Interrupting Time | Cycles/ms | 5/83 [8] | 5/83 [8] | 5/83 [8] |
| Rated Values | Rated Current | Permissible Tripping Delay (Y) | Sec | 2 | 2 | 2 |
| Related Required Capabilities | Current | Rated Maximum Design Voltage (V) Divided by K = (V/K) | kA rms | 23.0 | 38.0 | 38.0 |
| Related Required Capabilities | Current | Maximum Symmetrical (sym)Interrupting (K X I) | kA rms sym | 35 | 31.5 | 31.5 |
| Related Required Capabilities | Current | Short-Time Current (K x I) (Three Seconds) | kA rms sym | 35 | 31.5 | 40 |
| Related Required Capabilities | Closing and Latching(Momentary) | Asymmetrical | kA rms | 56 [4] | 50 [6] | 62 [6] |
| Related Required Capabilities | Closing and Latching(Momentary) | Peak | kA peak | 95 [5] | 85 [7] | 104 [7] |
Dimensions
| Type | Width (W) | Height (H) | Depth (D) | Drawout Aisle (DA)1,2 |
| Indoor GM38 | 48.0 (1,219) | 110.0 (2,794) | 130.0 (3,302) | 96.0 (2,438) recommended |
| Shelter-Clad Single-Aisle SGM38 | 48.0 (1,219) | 132.5 (3,366) | 234.5 (5,956) | 96.0 (2,438) included |
| Shelter-Clad Common-Aisle SGM38 | 48.0 (1,219) | 132.5 (3,366) | 363.8 (9,239) | 96.0 (2,438) included |
| Aisleless Non-Walk-In OGM38 | 48.0 (1,219) | 132.5 (3,366) | 139.4 (3,539) | 96.0 (2,438) recommended |
Footnotes:
1 If indoor switchgear is installed on a raised housekeeping pad, the pad must not extend further than 3" (75 mm) from the front of the switchgear to avoid interference with the use of the portable lift truck.
2 96" (2,438 mm) aisle space recommended and allows room for interchange of circuit breakers. Minimum aisle space required for handling circuit breakers with lift truck is 80" (2,030 mm).
| Continuous Current | 38-3AH3-1500 | 38-3AH3-31.5 | 38-3AH3-40 |
| 1,200 A | 800 (363) | 800 (363) | 825 (375) |
| 2,000 A | 900 (408) | 900 (408) | 925 (420) |
| 3,000 A | 1,000 (454) | 1,000 (454) | 1,025 (465) |
