Engineered Medium Voltage Switchgear Systems – up to 38kV
Indoor & Outdoor Applications – NEMA 1 / NEMA 3R
At SRi, we specialize in custom-configured Metal Clad Switchgear up to 38 kV, fully engineered for safety in industrial, utility, and infrastructure sectors. Our switchgear combines modularity, full compliance with ANSI/IEEE/NEMA standards, and reliable mechanical and electrical performance.


General Capabilities
– Rated Voltage: Up to 38 kV
– Current Rating: Up to 4000 A
– Short-Circuit Rating: Up to 63 kA Sym. – up to 170KA (2s peak withstand rating) – Enclosures: NEMA 1 (indoor) or NEMA 3R (outdoor), rain-tight, vented with filter accessible without entering high voltage compartment.
– Epoxy coated Bus System with C110 copper bus, silver or tin-plated, sized for rated current with optional expansion joints
Control & Protection Architecture
– Separate relay panels and control panels are located a safe distance away
– Relay Panel isolation ensures operational safety and full relay maintenance access even during servicing
– Relay Panels: Real-time protection, metering, event capture (IEEE C37.90) SCADA interface


Circuit Breaker Technology
All breakers are Draw-out Vacuum Circuit Breakers, with heavy-duty mechanical racking systems, allowing safe insertion/removal under de-energized conditions.
– Draw-out Mechanism: – Four positions: Connected, Test, Disconnected, removed – Safety shutters isolate primary disconnects – Secondary control contacts are self-coupling in connect positions
– Racking System Options: – Manual lever-operated – Worm-gear mechanical – Motorized remote racking, built-in (optional)
Voltage & Insulation Ratings |
||
|---|---|---|
Max Rated Voltage (kV) |
Power Frequency Withstand (kV, 1min) |
Impulse Withstand BIL (kV) |
4.76 |
19 |
60 |
15 |
36 |
95 |
27 |
60 |
125 |
38 |
80 |
150/170 |

Control & Protection Architecture
– Control Panels: LOTO (Lockout/Tagout) Implemented via built-in racking controls with logic interlocks. This means always ready without external racking setup time
– Panel isolation ensures operational safety and control continuity






