LT Switchgear
Low-tension switchgear sized and configured to spec for distribution boards and industrial control panels.
About LT Switchgear
LT (low-tension) switchgear is the family of devices that switch, protect and isolate circuits up to 1000 V AC: air circuit breakers on main incomers, moulded-case circuit breakers on feeders, motor protection circuit breakers and contactors on motor starters, and switch-disconnector-fuses and changeover switches for isolation and source selection.
Microtech supplies LT switchgear from Lauritz & Knudsen, Schneider Electric, Siemens and Mitsubishi Electric as an authorised channel promoter, so warranty and manufacturer support carry through. Typical ranges include L&K U-Power Omega and C-Power ACBs and dsine MCCBs, Schneider MasterPacT MTZ ACBs, Siemens SENTRON 3WA ACBs and Mitsubishi NF/NV breakers.
Selection starts with the prospective fault level at the point of installation. We choose the breaking capacity (Icu/Ics) and, for motor circuits, the utilisation category and coordination type, then check discrimination so a downstream fault does not trip the incomer. Switchgear can be supplied loose against your schedule or fitted and wired into panels built at our Varanasi and Lucknow facilities.
Key specifications
| Air circuit breakers | 400–6300 A (L&K U-Power Omega); up to 6300 A (L&K C-Power, Schneider MasterPacT MTZ); 630–6300 A (Siemens 3WA); fixed or draw-out |
|---|---|
| ACB breaking capacity | L&K Icu 50 / 65 / 80 / 100 kA (up to 100 kA at 415 V) with Icu = Ics = Icw (1 s); Siemens 3WA Icu 55–150 kA at 500 V; MasterPacT MTZ2/MTZ3 up to 150 kA at 440 V |
| Moulded-case circuit breakers | L&K dsine DN and DZ, DU and DY series; Mitsubishi NF and NV (earth leakage) series including WS-V |
| Motor protection | MPCBs with short-circuit, overload and phase-loss protection, e.g. L&K MOG |
| Contactors | L&K MNX 9–650 A (AC-3); MCX 4-pole 18–900 A (AC-1) for source transfer; MO C capacitor-duty |
| Isolation and changeover | Switch-disconnector-fuses and changeover switches (L&K SDF and COS ranges) |
| Trip units | Microprocessor releases with true-RMS sensing; ZSI, REF and dual setting groups on L&K ACBs; MicroLogic X on MasterPacT MTZ |
| Communication | Modbus TCP and PROFINET on Siemens 3WA (COM190); communication options on L&K and Schneider ACBs |
Features & benefits
- Breaking capacity matched to the calculated fault level, not over-specified
- Discrimination and cascading checked between incomer, feeder and final circuits
- Type 1 or Type 2 coordinated motor starter combinations
- Several manufacturer ranges, so you can stay with your plant's existing make
- Genuine stock through the manufacturer channel, with warranty support
- Supplied loose against a schedule, or fitted and wired inside a Microtech panel
- Replacement and retrofit of existing breakers, including draw-out ACB upgrades
Where it’s used
- PCC, MCC and distribution board building
- Factory incomers and transformer LT side
- Commercial buildings, hospitals and malls
- DG changeover and source transfer
- Motor feeders for pumps, fans and compressors
- Solar and battery storage installations
Standards & compliance
LT Switchgear — FAQs
How do I choose between an ACB and an MCCB?
ACBs are used for large incomers and couplers — current ranges start at 400 A or 630 A depending on make — where high short-time withstand, draw-out construction and adjustable protection matter. MCCBs cover feeders and smaller incomers up to their frame limits. The fault level and the need for selectivity usually decide the boundary.
What do Icu, Ics and Icw mean on a breaker?
Icu is the ultimate short-circuit breaking capacity. Ics is the service breaking capacity — the fault the breaker can clear and remain in service. Icw is the current an ACB can carry for a set time, usually 1 s, without tripping, which allows a downstream device to clear the fault first. Ranges such as L&K U-Power Omega are rated Icu = Ics = Icw.
Can I buy switchgear loose, without a panel?
Yes. We supply against your switchgear schedule as an authorised channel promoter for the brands listed, so warranty and manufacturer support carry through.
Can you replace an old ACB with a current model?
Usually yes. We check the existing frame, cradle dimensions, busbar connections and control wiring, then propose a direct replacement or a retrofit kit from the manufacturer range that fits with minimal panel modification.
