HT Panel and 11 kV VCB Panel Manufacturer in Vadodara, India

An HT panel is medium-voltage switchgear — on Indian distribution networks that usually means 11 kV. It sits on the incoming side of the transformer and does three jobs: it isolates, it switches, and it protects the transformer and the cable feeding it. The switching device is normally a vacuum circuit breaker, with a load break switch or isolator where the duty does not need a breaker.

This is a different standard from an LT board. Metal-enclosed MV switchgear is covered by IEC 62271-200, not IEC 61439, and its type test belongs to the switchgear manufacturer. Wisdom Techno Solutions works both ways, project by project: we integrate type-tested OEM cubicles, and we build our own assemblies where the project calls for it. The offer states which, because it determines whose certificate you receive.

• 11 kV VCB panels — incoming, outgoing, metering and bus-coupler cubicles
• Load break switch and isolator cubicles where a breaker is not required
• Numerical protection relays — overcurrent, earth fault, differential, directional
• CT and PT metering cubicles to the DISCOM's requirement
• Both routes supported: type-tested OEM cubicles integrated by us, or our own build
• Optional PLC and SCADA integration for remote control and monitoring

From a single incoming VCB ahead of one transformer to a multi-cubicle 11 kV lineup, the specifications below cover our standard build.

The table below is the standard build. Ratings on an MV assembly are declared per project against the utility's fault level and the switchgear selected — we do not publish a blanket figure, because it would not mean anything without the configuration it belongs to.

These two are on opposite sides of the transformer and are governed by different standards. Specifying one with the other's clauses is a common and expensive tender error.

On medium voltage, the type test belongs to the switchgear manufacturer, not to the panel builder. An MV cubicle design is type-tested as a design — internal arc behaviour, short-time withstand, dielectric performance, mechanical endurance. That certificate names the OEM and the cubicle, and no amount of good assembly work transfers it to somebody else. This is worth saying plainly, because it is the point on which MV tenders most often go wrong.

So we work two ways, and the offer says which. On the first route we integrate type-tested OEM cubicles: the cubicle, breaker and interlocks come from the switchgear manufacturer with their certificate, and we do the relay selection and setting, the CT and PT selection, the control and metering wiring, the schematics, the earthing, the cable termination arrangement and the commissioning. On the second route we build the assembly ourselves to the project's requirement. Which route suits a project depends on the specification: if the tender requires a type-test certificate to IEC 62271-200 for internal arc classification, that means an OEM cubicle, and we will say so rather than offer something that cannot satisfy the clause.

The practical guidance for a buyer is simple. Decide before the enquiry goes out whether you need a type-test certificate and internal arc classification, because that single line determines the route, the cost and the delivery time. And ask every bidder the same question we answer here — whose certificate covers the cubicle. A bidder who is vague about it is telling you something. And where a clause cannot be met on the route offered, we say so — a bid that quietly reinterprets the specification is worse than one that names the limit. When it is not possible to satisfy a requirement, that belongs in the offer, not in a discovery at the factory acceptance test.

Send these and every offer you receive will be comparable:

• Single line diagram, from the utility incoming point to the transformer
• Utility fault level at the incoming point, and the DISCOM's metering requirement
• Transformer rating, vector group and impedance
• Number and type of cubicles required — incoming, outgoing, metering, bus coupler
• Whether a type-test certificate and internal arc classification are required
• Protection philosophy and relay make preferred, if any
• CT and PT ratios, classes and burdens if already fixed
• Cable size, type and entry direction
• Control supply available — 110 V DC, 220 V DC, or to be included
• Switchroom dimensions, access route and floor loading
• SCADA or remote monitoring requirement

The fault level and the DISCOM's metering requirement are the two items that most often hold an MV offer up. Both come from the utility rather than from you, so it is worth starting them early.

• Writing IEC 61439 into an HT specification. IEC 61439 is a low-voltage standard. For 11 kV switchgear the standard is IEC 62271-200, and a clause citing the wrong one cannot be satisfied by anybody.
• Asking the panel builder for a type-test certificate in its own name. On MV that belongs to the switchgear manufacturer. Ask instead whose certificate covers the cubicle offered.
• Leaving internal arc classification unstated. It is not automatic, it materially changes the cubicle and the cost, and in an occupied switchroom it is usually the requirement that matters most.
• Forgetting the utility's own requirements. Metering arrangement, CT class and the protection settings the DISCOM will accept are set by them, and retrofitting them later is expensive.
• Underestimating the switchroom. MV cubicles need clearances, a cable trench or floor cut-outs, an access route wide enough to bring them in, and floor loading that takes them. It is worth checking before the order, not at delivery.
• Treating the control battery as an accessory. A tripping supply that fails means a breaker that cannot trip. The battery, charger and its monitoring belong in the scope from the start.
• Omitting the fault level from the enquiry. Without it no vendor can size the assembly correctly, and the offers stop being comparable.
• Writing "as per IEC 61439" with no part and no year. The verification evidence a manufacturer submits has to be traceable to a specific standard and configuration.

Wisdom Techno Solutions builds and integrates this assembly at our works in Vadodara, Gujarat, for industrial, EPC and infrastructure projects across India. Every board is routine-verified in-house before dispatch, with the test records, approved drawings, bill of materials with makes as supplied and protection settings as applied issued with it. Customer, consultant and third-party witnessed testing are all supported.

Engineering guides from our team on the calculations and design decisions behind an HT panel:

• Circuit breaker selectivity, discrimination and cascading
• Icu vs Ics vs Icw — selecting the correct short-circuit rating
• Internal arc fault and IEC TR 61641 testing
• Electrical panel earthing and earth busbar design
• Electrical load list and transformer / incomer sizing
• Old ACB retrofit vs complete panel replacement
• Electrical panel FAT and routine test checklist
• How to prepare an LT panel technical specification and RFQ

If this is not the right fit for your layout, these are the alternatives we build to the same standard:

• PCC panels — power distribution from the transformer incomer to the plant's outgoing feeders
• PMCC panels — PCC distribution and MCC motor control combined in one assembly
• DG synchronization panels — two or more generators running in parallel with load sharing
• AMF panels — automatic mains failure detection and single-generator changeover
• Retrofitting and upgrades — modernising an existing board instead of replacing it
• IEC 61439 panels — how design verification and routine verification work under the standard

Email your single line diagram, load list and system fault level and our engineers will come back with a technical offer. Not sure what to send? See what a panel manufacturer needs in order to quote accurately.