GM-SG / GM-SG-AR — ANSI switchgear with GMSG withdrawable vacuum circuit breakers up to 27 kV, 63 kA (including arc-resistant)
GM-SG switchgear assemblies and arc-resistant GM-SG-AR to ANSI/IEEE standards for maximum voltages up to 27 kV and breaking current up to 63 kA. Horizontally withdrawable GMSG vacuum circuit breakers, rated currents up to 4000 A. For industrial plants, commercial buildings and utilities.
- Rated voltage (max.)
- 4.76; 8.25; 15; 17.5; 27 kV
- Breaking current
- 25–63 kA (by voltage class)
- Rated current
- 1200, 2000, 3000 A; 4000 A with forced cooling (27 kV: up to 3000 A)
- Impulse withstand voltage (BIL)
- 60–125 kV
Price, availability and lead time on request. We help with analogue selection, customs clearance and delivery.
Description
GM-SG and GM-SG-AR are medium-voltage air-insulated metal-clad switchgear assemblies for markets with ANSI/IEEE standards. They are made by the manufacturer's American division. The panels are fitted with horizontally withdrawable GMSG vacuum circuit breakers with a spring operating mechanism 3AH3 that is the same for all ratings. Since 1998 more than 200,000 of these mechanisms have been produced, and the vacuum interrupters have a mean time to failure of more than 55,000 years.
The design is two-tier, so two circuit breakers are placed in one section, saving floor area. Racking out is performed with the doors closed, the lower breaker is racked out onto the floor without a truck, and the breaker mechanism is accessible from the front. The switchgear is made for maximum voltages of 4.76 kV, 8.25 kV, 15 kV, 17.5 kV and 27 kV.
The breaking currents are 40, 50 and 63 kA (4.76 kV), 40 kA (8.25 kV), 25–63 kA (15 kV), 50 and 63 kA (17.5 kV) and 25 and 40 kA (27 kV). The rated currents are 1200, 2000 and 3000 A, and 4000 A with forced cooling. For 27 kV they are 2500 and 3000 A. The power-frequency withstand voltage is from 19 to 60 kV and the impulse withstand voltage from 60 to 125 kV.
The breaker withstands up to 100 full short-circuit breaking operations and 10,000 operations before overhaul, with optional 3-cycle interruption. Interlocks allow a breaker of a higher rating to be racked into a panel of a lower rating but not the other way round, so one universal spare breaker covers the whole range. Schemes with main and transfer busbar systems and generator circuit breakers to IEC/IEEE 62271-37-013 are supported.
GM-SG-AR is an arc-resistant version tested to IEEE C37.20.7 for a current up to 63 kA for 0.5 s with type 2B accessibility. A factory-made pressure relief duct with a modular exhaust system is installed on top, and the instruments and control circuits are moved into an isolated compartment. Versions for indoor installation and outdoor Shelter-Clad (NEMA 3R) and Shelter-Clad+ are available. Options are the SIERS remote racking system, Sm@rtGear for remote diagnostics and control, and the SIQuench active arc quenching module. The switchgear complies with ANSI, IEEE and NEMA, and UL/c-UL certification is possible. Applications are industrial plants, commercial buildings, electric utilities and cogeneration plants.
Technical specifications
| Rated voltage (max.) | 4.76; 8.25; 15; 17.5; 27 kV |
|---|---|
| Breaking current | 25–63 kA (by voltage class) |
| Rated current | 1200, 2000, 3000 A; 4000 A with forced cooling (27 kV: up to 3000 A) |
| Impulse withstand voltage (BIL) | 60–125 kV |
| Circuit breaker | withdrawable vacuum GMSG with 3AH3 mechanism, up to 100 full short-circuit breaking operations, 10,000 operations before overhaul |
| Arrangement | single- or two-tier (two breakers per section) |
| Arc resistance (GM-SG-AR) | IEEE C37.20.7, type 2B, up to 63 kA 0.5 s |
| Options | SIERS (remote racking), Sm@rtGear, SIQuench |
| Standards | ANSI, IEEE, NEMA; UL / c-UL |
Request a price and lead time
GM-SG / GM-SG-AR — ANSI switchgear with GMSG withdrawable vacuum circuit breakers up to 27 kV, 63 kA (including arc-resistant). We reply within one business day.
Or email sales@usk.ua or call 044 339-50-20.
Questions and answers
What voltages and breaking currents is GM-SG made for?
Maximum voltages of 4.76 kV, 8.25 kV, 15 kV, 17.5 kV and 27 kV. Breaking currents from 25 to 63 kA depending on the voltage class.
What is the arc-resistant version and to which standard is it tested?
GM-SG-AR is tested to IEEE C37.20.7 for a current up to 63 kA for 0.5 s, accessibility type 2B.
What is the service life of the GMSG breaker?
Up to 100 full short-circuit breaking operations and 10,000 operations before overhaul. The 3AH3 mechanism is the same for all ratings.
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