NMX‑SWB‑30 / Rev 00 / electrical distribution / fault · discrimination · segregation 2026 · Product Page

NMX-SWB-30 · ENGINEERED TO ORDER — NAVAL & LAND SWITCHBOARDS

A switchboard is sized for the fault, not for the load.

Name: Naval and Land Switchboards
Brand: Neometrix

The running current sets the copper and almost nothing else. What actually sizes the assembly is the prospective short-circuit current — tens of kiloamps for a fraction of a second — because current that large generates electromagnetic forces between parallel busbars that try to tear them off their supports. So bar spacing, insulator pitch and bracing matter more than cross-section, and the withstand is proven by test. The second half of the job is discrimination: the nearest protective device must clear a fault and nothing upstream of it, because overlapping settings mean a failed fan takes down the whole platform. That makes the coordination study the real deliverable. And the third is that a maintainer has to work on one section while the rest stays live, which turns segregation, shutters, interlocks and internal arc containment into structure rather than options. Equipment of this class has been quoted across land and naval switchboard requirements for defence services; no delivered switchboard is claimed — the class is engineered to order.

Enquire — switchboards Capability sheet (PDF)

Illustrative of the class — a row of five tall floor-standing light-grey painted steel switchboard cubicles bolted together into a continuous line-up in a clean assembly hall, each about two metres high with hinged front doors, plain recessed panel areas, brushed stainless handles, a continuous plinth along the base and blank legend strips above each door, with moulded-case breakers and coloured cabling visible in the open upper compartments, no people and no readable markings

Fig · 01 The line-up — sections bolted into one assembly, so a fault in any of them is somebody else's problem, not everybody's

Sized by

fault currentnot running amps

Judged on

discriminationthe nearest device only

Worked on

section by sectionthe rest stays live

Survives

shock & saltand restricted access

Status

engineered to orderquoted class

ISO 9001 / 14001 Engineered to order Electrical distribution Routine & type tested Noida · India

Overview

The load schedule tells you almost nothing.

It sets the copper and the frame sizes. Every other decision in the assembly — spacing, bracing, segregation, settings — comes from what happens in the fraction of a second when something fails.

Illustrative of the class — close view into the open rear of a switchboard cubicle: three horizontal flat bright copper busbars running the width of the compartment one above the other, each clamped at intervals into dark moulded insulator blocks bolted to the steel side frames, short vertical copper droppers bolted to the main bars with bright hardware, a smaller copper earth bar low down and neat black cable tails leaving downward through a gland plate, clean light-grey painted steelwork around them, no people and no readable markings

Fig · 02 The bars — the insulator pitch and the bracing are the design; the cross-section is the easy part

Fault current is a mechanical problem before it is an electrical one. Two parallel conductors carrying current in the same direction attract; in opposite directions they repel. At normal running currents that force is negligible. At a short circuit — tens of kiloamps — it becomes very large indeed, and it arrives as a shock load, not a steady push. If the bars are not braced closely enough they deflect, and if they deflect far enough they either touch, which turns a single-phase fault into a three-phase one, or they tear out of their insulators. This is why the meaningful specification is short-circuit withstand for a stated duration, why insulator pitch is a calculated dimension rather than a convenient one, and why the assembly is type tested rather than assured by adding up component ratings.

And then the protection has to be selective. Every circuit has a device meant to protect it, and those devices sit in series: consumer, distribution board, section, incomer. When a fault occurs, exactly one of them should operate — the nearest one upstream of the fault. Achieving that means the time-current characteristics have to be separated deliberately at every level, with enough margin that the downstream device is definitely faster at the fault levels that can actually occur. Get it wrong and the failure mode is spectacular in the worst way: a small, cheap, entirely survivable fault on one consumer trips a much bigger breaker upstream and takes everything with it. That is why the coordination study is the deliverable that matters and the device schedule is downstream of it.

Then it has to be lived with. A board on a vessel or in a field formation cannot be shut down for maintenance — there is nothing to fall back on. So the assembly is divided so that a maintainer can isolate and work on one section with the others still energised, which is what segregation form actually means, and the barriers, shutters and interlocks that make it safe are structural. On top of that the platform imposes shock, vibration, salt, heat and humidity, and an access envelope fixed by a compartment that already exists.

Equipment of this class has been quoted across land and naval switchboard requirements for defence services. No delivered switchboard is claimed: the class is engineered to order, and the record is stated as it stands.

Braced

For the forces, not the amps

Insulator pitch and bracing set by short-circuit withstand, and proven by type test.

Selective

One device operates

A coordination study with real margin — so one consumer is lost, not the platform.

Maintainable

Worked on while live

Segregation, shutters and interlocks — because distribution cannot be switched off.

Architecture

Size, brace, coordinate, segregate.

The schematic follows the design — sizing against fault rather than load, bracing against the forces that follow, coordinating so only the nearest device operates, and segregating so the board can be maintained — then the assembly itself.

FIG · 03SWITCHBOARD ARCHITECTURE · ENCLOSURE + STRUCTURE / BUSBARS + FAULT WITHSTAND / PROTECTION + DISCRIMINATION / CONTROL, MONITORING + TEST

Fig · 03 Lose one consumer, not the platform — which at sea is the entire point

Arc · 01

Enclosure & Structure

Ingress protection, shock mounting, segregation form, cable entry — and an access envelope the compartment already fixed.

Arc · 02

Busbars & Fault Withstand

Spacing, insulator pitch, bracing, clearance and creepage — sized against short-circuit forces and proven by type test.

Arc · 03

Protection & Discrimination

Breakers, relays, settings, earthing — and the coordination study that makes the nearest device the only one that operates.

Arc · 04

Control, Monitoring & Test

Metering, indication, interlocks — and the routine and type tests that turn a fabricated cabinet into a qualified assembly.

Specifying a board for a vessel or a formation? Send the load schedule, the fault levels, the compartment envelope and the environmental class — a clause-by-clause compliance matrix within two working days · [email protected]

Send tender spec

Specifications

Reference assemblies, built to the platform.

The parameters below describe reference assemblies. Busbar rating and withstand, cubicle count and segregation form, protection ranges and settings, and the environmental qualification all follow from three givens: the load schedule, the fault levels at the point of installation, and the compartment or vehicle the board has to live inside.

Illustrative of the class — close view of the front of a single switchboard cubicle with its door swung open in a clean assembly hall: a vertical stack of three moulded-case circuit breakers on plain grey escutcheon plates each with a black operating toggle and a blank legend strip beside it, blank square meter faces set into the door panel, a hinged transparent inner cover standing open, copper busbar and looms of small control wiring in slotted trunking visible in the cubicle behind, no people and no readable markings

Fig · 04 The front — where segregation is felt: one section open and worked on, the rest of the board still energised

Where switchboards go wrong

Sized on running current — the copper is right and the bracing is not, so the first real fault distorts the bars off their supports and turns one fault into three. Discrimination never studied — devices selected from a catalogue by rating alone, characteristics overlapping, and a trivial fault on one consumer tripping the incomer. Segregation form chosen on price — then every maintenance task needs a full shutdown, on a platform that cannot provide one. Shock and vibration treated as a finish — a board qualified for a building, installed on something that moves. Cable entry and access designed after the compartment is fixed — and the assembly that fits on paper cannot be installed or maintained. And type tests assumed from a component list — every part certified, the assembly never tested, and the withstand rating therefore unproven.

So the discipline runs the other way. Fault levels are established first and the assembly is sized and braced against them, with the withstand demonstrated by type test on the built configuration. A coordination study is produced, with margin at every level, and the device schedule falls out of it rather than preceding it. Segregation form is chosen from the maintenance concept — what has to stay live while what is worked on — and shutters, barriers and interlocks follow. Shock, vibration and the salt environment are qualified for the platform class. The compartment envelope, cable entry and door swing are design inputs from the first drawing. And routine tests are run on every assembly, with temperature rise, clearance and creepage, and protection settings verified rather than inherited.

Full specification — expand

System	Naval & land switchboards — enclosure & structure, busbars & fault withstand, protection & discrimination, control, monitoring & test
Governing Idea	Sized for the fault, not the load — prospective short-circuit current and the electromagnetic forces it produces size the assembly; running current only sets the copper
Busbars	Spacing, insulator pitch, bracing, clearance and creepage — because parallel bars carrying fault current repel hard enough to deflect or tear out; withstand stated for a duration and proven by test
Discrimination	The nearest device clears the fault and nothing upstream — time-current characteristics separated with margin at every level, so one consumer is lost rather than the platform
The Deliverable	The coordination study is the real engineering output; the device schedule follows from it rather than preceding it
Segregation	Form chosen from the maintenance concept — what must stay live while another section is worked on — with barriers, shutters and interlocks following from that decision
Internal Arc	Containment and pressure relief designed in, so an internal arc fault stays inside the section it started in
Environment	Shock, vibration, salt atmosphere, heat and humidity qualified for the platform class — a board qualified for a building is not qualified for something that moves
Physical Envelope	Footprint, weight, cable entry direction, door swing and maintenance access taken as design inputs from the first drawing, because the compartment already exists
Earthing	Earth bar continuity through the line-up, bonding of doors and removable parts, and a defined earthing arrangement for the platform
Testing	Routine tests on every assembly and type tests on the configuration — temperature rise, short-circuit withstand, clearance and creepage, protection settings; never assumed from a component list
The Split	The site's frequency converter and shore power supply supplies power to a berthed vessel from ashore and connects into its board. This is the platform's own distribution, and it works alongside or at sea. The mobile rectifier and battery charger converts and charges; this distributes and protects. And the circuit breaker and relay test bench is the machine that tests the very protection devices this board's discrimination depends on — the loop closes
Scope Boundary	Ours: enclosure & structure, busbar sizing & bracing, protection & coordination study, earthing, control & metering, shock & environmental qualification, routine & type testing, installation, commissioning, documentation, training, spares & AMC — including build to the customer's specification. Bought-in certified: breakers, relays, meters, control hardware. The customer's: the platform, its load schedule and its fault levels
Status	Engineered to order — equipment of this class quoted across land and naval switchboard requirements for defence services; no delivered switchboard is claimed

PDF · 1 page

Naval & Land Switchboards — Capability Sheet

Tender Response

Send load schedule, fault levels & envelope — compliance matrix in two working days

Variants

One discipline, four boards.

What changes is where the board lives, how much of the platform depends on it, and whether it is new or replacing something already installed.

Var · 01

Naval Main & Distribution Boards

Shock-qualified, salt-hardened, segregated — where nothing can be switched off and access is whatever the compartment allows.

Var · 02

Land Unit-Level Boards

Distribution for a field formation — transportable, rugged, and simple enough to be maintained where it is deployed.

Var · 03

Shore-Supply & Changeover Boards

The interface between two sources — interlocked so they can never be paralleled by accident.

Var · 04

Retrofit & Upgrade

New protection and segregation into an existing envelope — usually the hardest case, and the most common one.

Applications

Wherever losing power loses everything else.

The platforms and installations where distribution has no fallback.

A · 01Naval vessels & auxiliaries

A · 02Field formations & unit-level distribution

A · 03Shore establishments & depots

A · 04Industrial plant distribution

A · 05Test facilities & laboratories

A · 06Mobile & containerised power

FAQ

Common questions.

Plain-language answers from the engineering team.

Q · 01 Why does fault current matter more than the load?

Because the load decides how much copper you need, and the fault decides whether the assembly survives being used. Running current is a thermal problem: enough conductor cross-section and enough ventilation that nothing exceeds its temperature rise limit, which is straightforward arithmetic. A short circuit is a mechanical problem, and a violent one. When tens of kiloamps flow through parallel busbars, the magnetic field of each bar acts on the current in its neighbours, and the resulting force scales with the square of the current — so a fault current twenty times the running current produces roughly four hundred times the force. It also arrives almost instantaneously, so the bars are shock-loaded rather than pushed steadily. Two failures follow if the design ignored this. The bars deflect far enough to touch, converting a single-phase fault into a three-phase one and making everything worse; or they tear out of their insulators, after which the assembly is scrap and the arc is uncontained. Preventing that is a matter of geometry rather than of copper: how far apart the bars sit, how frequently they are supported, how stiff the supports and their mountings are. That is why the number that characterises a switchboard is its short-circuit withstand for a stated duration, why insulator pitch is calculated rather than convenient, and why a serious specification requires the assembly to be type tested rather than certified by adding up the ratings of its parts.

Q · 02 What is discrimination, and why is it a study rather than a selection?

Discrimination — also called selectivity — is the property that when a fault occurs, exactly one protective device operates: the nearest one upstream of the fault, and nothing above it. It is a study rather than a selection because protective devices do not act instantly or at a single threshold; each has a time-current characteristic, a curve describing how long it takes to operate at each level of current. Making a system selective means arranging those curves so that at every fault level which can actually occur at every point in the network, the downstream device is reliably faster than the one above it — with enough margin to absorb manufacturing tolerance, temperature, and the fact that a breaker's own opening time is not a precise number. That requires knowing the fault level at every node, which depends on source impedance, cable lengths and sizes, and what else is running. The reason it matters so much on a platform is the failure mode. Without it, a small fault in one consumer — a fan motor, a lighting circuit, a damaged cable tail — can trip a breaker several levels upstream, which de-energises everything downstream of that breaker, most of it perfectly healthy. On a building that is an outage; on a vessel it can mean losing propulsion or steering because of a failed pump somewhere else entirely. So the coordination study is the deliverable, and the device schedule is a consequence of it, not an input to it.

Q · 03 What does a segregation form actually buy?

It buys the ability to work on part of the board without switching off the rest — which sounds like a convenience and is, on a platform, a hard requirement. A switchboard can be built as essentially one large box with everything inside it, or progressively divided by internal barriers so that the busbars are separated from the functional units, each functional unit from its neighbours, and the terminals for outgoing cables separated from both. Each level of separation costs space, weight and money, and each buys a specific capability. At the lowest level, any work inside the enclosure means isolating the whole board. At higher levels, a maintainer can open one section, work on its device and terminals with the busbars and adjacent sections still live and shuttered, and restore it without the platform noticing. The right choice comes from the maintenance concept, not from a price list: what must remain energised while a fault is repaired or a routine check is done, and who will be doing that work in what conditions. On a vessel or a deployed formation the answer is usually that almost everything must stay live, because there is no alternative supply to fall back on and no convenient moment. The related items follow from the same decision: shutters that close automatically over live contacts, barriers that contain an internal arc fault within the section that started it, and interlocks that prevent a door being opened or a device withdrawn in the wrong sequence.

Q · 04 What changes when the board goes to sea?

Almost everything structural, and nothing about the electrical principles. The circuit design is recognisably the same; the assembly around it is not. Shock is the largest difference: a naval board may have to remain functional after a severe transient acceleration, which drives mounting arrangements, the stiffness of the frame, how devices are fixed rather than merely clipped, and how cables are restrained so their mass does not tear terminations. Vibration is continuous rather than exceptional, so anything that can loosen will, and fastener selection and locking become qualification items. The salt atmosphere attacks every dissimilar-metal junction and every paint defect, so material selection, plating, painting and the treatment of earthing points all change. Heat and humidity are worse in a closed compartment than in a switchroom, and the compartment usually cannot be made bigger, so temperature rise has less margin. Access is whatever the compartment permits: doors that cannot open fully, cable entry from a fixed direction, and no room to withdraw a device on a trolley. And the operational constraint sits behind all of it — there is no second board, no mains supply to fall back on, and no convenient outage window. That is why a board qualified for a building is not qualified for a vessel even if its electrical ratings are identical, and why the environmental and shock qualification is treated as part of the design rather than as a certificate collected afterwards.

Q · 05 How does this differ from your shore supply and rectifier products?

They sit at different points in the same electrical chain, and the distinction is worth being precise about because all three involve heavy current. The frequency converter and shore power supply system is a source: it sits ashore, takes the local supply, converts it to the frequency and voltage a vessel needs, and delivers it down a cable to a berthed ship — where it connects into that ship's switchboard. It exists only while the vessel is alongside. The mobile rectifier and battery charger is a converter: it changes the form of the power, from alternating to direct current, for charging and for consumers that need it. This equipment is neither. A switchboard receives, distributes and protects — it is the point at which one incoming supply, whatever its origin, becomes many protected outgoing circuits, and it works identically whether the vessel is alongside on shore power, at sea on its own generation, or a formation is running on its own set. That is also why the third relative is the interesting one: the circuit breaker and relay test bench exists to verify that the very devices this board's discrimination depends on actually operate at their set characteristics — because a coordination study is a set of assumptions about breaker behaviour, and a bench is how those assumptions get checked.

Q · 06 What do you build, what is bought in — and what is claimed?

Divided honestly. What Neometrix provides: the enclosure and structure — fabrication, ingress protection, shock and vibration mounting, segregation form, cable entry and the access arrangement the compartment permits; the busbar system — sizing, support pitch, bracing, clearance and creepage, and the short-circuit withstand the assembly is proven to; the protection design and the coordination study, which is the real engineering deliverable, with settings established from the fault levels at every node and margin at every level; earthing continuity through the line-up and bonding of doors and removable parts; control, metering, indication and interlocks; shock and environmental qualification for the platform class; and the routine and type testing that turns a fabricated cabinet into a qualified assembly — temperature rise, withstand, clearances, settings, verified rather than inherited from a component list; plus installation, commissioning, documentation, training, spares and AMC, including build to the customer's own specification, which is how requirements of this class are framed. What is bought-in certified: breakers, relays, meters and control hardware — proprietary products of established makers, integrated rather than imitated. What is the customer's: the platform, its load schedule, and the fault levels the board must be designed against. And the record, stated plainly: equipment of this class has been quoted across land and naval switchboard requirements for defence services. No delivered switchboard is claimed; the class is engineered to order, around the platform it has to power.

↗

The power family from Neometrix.

Supply it, convert it, distribute it — and test the devices that protect it.

↗ Source

Frequency Converter & Shore Power Supply

Power delivered to a berthed vessel from ashore — and into its board.

↗ Convert

Mobile Rectifier & Battery Charger Unit

Changing the form of the power rather than distributing it.

↗ Verify

Circuit Breaker & Relay Test Bench

The bench that checks the devices a coordination study assumes.

Browse all Neometrix product lines.

Get a quotation

Send the load schedule
and the fault levels.

The projects desk replies within two working days with a clause-by-clause compliance matrix and a budgetary quotation. Write to [email protected] or use the form.

Enquire — switchboards Capability sheet (PDF) +91 7777 876 876

ISO 9001 / 14001 ENGINEERED TO ORDER — NAVAL & LAND SWITCHBOARDS SIZED FOR THE FAULT · DISCRIMINATION IS THE DESIGN · WORKED ON WHILE THE REST STAYS LIVE ENGINEERED IN NOIDA · INDIA

A switchboard is sized for the fault, not for the load.

The load schedule tells you almost nothing.

For the forces, not the amps

One device operates

Worked on while live

Size, brace, coordinate, segregate.

Enclosure & Structure

Busbars & Fault Withstand

Protection & Discrimination

Control, Monitoring & Test

Reference assemblies, built to the platform.

Where switchboards go wrong

One discipline, four boards.

Naval Main & Distribution Boards

Land Unit-Level Boards

Shore-Supply & Changeover Boards

Retrofit & Upgrade

Wherever losing power loses everything else.

Common questions.

The power family from Neometrix.

Frequency Converter & Shore Power Supply

Mobile Rectifier & Battery Charger Unit

Circuit Breaker & Relay Test Bench

Send the load schedule
and the fault levels.

Similar Products

Share This Page

A switchboard is sized for the fault, not for the load.

The load schedule tells you almost nothing.

For the forces, not the amps

One device operates

Worked on while live

Size, brace, coordinate, segregate.

Enclosure & Structure

Busbars & Fault Withstand

Protection & Discrimination

Control, Monitoring & Test

Reference assemblies, built to the platform.

Where switchboards go wrong

One discipline, four boards.

Naval Main & Distribution Boards

Land Unit-Level Boards

Shore-Supply & Changeover Boards

Retrofit & Upgrade

Wherever losing power loses everything else.

Common questions.

The power family from Neometrix.

Frequency Converter & Shore Power Supply

Mobile Rectifier & Battery Charger Unit

Circuit Breaker & Relay Test Bench

Send the load scheduleand the fault levels.

Similar Products

Share This Page

Send the load schedule
and the fault levels.