Double Door MCB Box: Sizes, Price per Way and Who Needs One

What is a double door MCB box?

A double door MCB box is a distribution board with two doors. The inner door is a cover with a slot cut in it: only the MCB levers show, while the busbar, terminals and wiring stay behind it. The outer door closes over the whole front. Someone resetting a tripped breaker opens one door; only an electrician opens both.

We make the VIYONA MCB distribution double door range in 4, 6, 8, 10, 12 and 16 way, from ₹750 to ₹1,410 MRP, plus three phase TPN double door boards, at our works in Marol, Andheri East, Mumbai.

The two doors of a double door DB

Drawn by us, not to scale. The general layout of a double door board; ask your dealer for the exact dimensions of each size.

Double door MCB box sizes and prices

Six single phase sizes, each a fixed number of ways. Printed MRPs from our current catalogue:

Each step up adds only ₹95 to ₹200, so the smallest size that fits today is rarely the best buy. Photos are on the MCB distribution double door product page.

Price per way: the bigger board is cheaper per circuit

Divide each MRP by its ways and the larger boards come out far cheaper per circuit:

• 4 way: about ₹188 per way
• 8 way: about ₹124 per way
• 12 way: about ₹101 per way
• 16 way: about ₹88 per way

The fixed parts of a board, the enclosure, the two doors and the hinges, cost about the same whatever the way count, so every extra way is cheap. That is the argument for buying two or four spare ways: at the 12 to 16 way step, four extra ways cost ₹200.

Our MCB box size list puts every box we make, single and double door, in one table.

Who should choose a double door board?

The second door earns its price where many people pass the board, or where the room is dusty or busy:

• Shops: staff reset a breaker without touching live parts
• Offices: a board in a corridor or pantry
• Housing society common areas: lift lobby and stair lighting
• Workshops and godowns: dust and handling

For a board inside a flat, behind the main door of a home, the SPN white line MCB box at ₹380 to ₹950 is usually enough. Our shop electrical points guide shows a typical shop board.

Double door vs SPN white line: the price gap

At similar sizes, our double door boards cost roughly 1.5 to 2.1 times the white line SPN box:

• 6–8 way white line (372): ₹480; 8 way double door (383): ₹995
• 10–12 way white line (373): ₹620; 12 way double door (385): ₹1,210
• 16–18 way white line (374): ₹950; 16 way double door (386): ₹1,410

On a single flat the difference is a few hundred rupees. On a project of forty flats it is significant, which is why builders often fit white line boxes in flats and double door boards in the common areas.

Our DB box vs MCB box guide explains the terms dealers use for each.

Which size double door board for a home or shop?

Count every device on the rail: outgoing circuits + 2 ways for a DP main + 2 for an RCCB + 2 spare.

• Small shop: DP main, RCCB, lights, counter, sign board, AC, two spare = 10 ways. Choose 10 way (384, ₹1,090).
• 2BHK flat: DP main, RCCB, ten circuits, two spare = 16 ways. Choose 16 way (386, ₹1,410).
• Society lift lobby: DP main, RCCB, three lighting circuits, two spare = 9 ways. Choose 10 way (384, ₹1,090).

The ratings for each circuit come from our MCB for home guide; the lighting circuits are explained on the 6 amp MCB page.

Three phase: TPN double door boards

The same double door construction is made for three phase supplies as TPN boards: 4 way (387, ₹2,620), 6 way (388, ₹3,050) and 8 way (389, ₹3,350). Two more TPN versions are listed with T.V. and telephone provision: 6 way (390) and 8 way (391), both ₹3,015.

A TPN board has three phase busbars and takes a four pole main. It is for bungalows, larger shops and offices with a three phase meter, not for a single phase flat.

The price jump from single phase is steep: a 4 way TPN board costs more than a 16 way single phase double door board, because it carries three busbars, a neutral and room for a four pole incomer. Buy one only when the meter is three phase.

The TPN MCB box page covers sizing and the parts that go in it, and the SPN vs TPN guide explains how to tell which supply you have.

What goes inside, and what it costs

For a small shop on a 10 way double door board, with a double pole MCB as the main and four single pole MCBs, our parts at MRP come to:

• 384 10 way double door: ₹1,090
• VIYONA 412 40A double pole MCB: ₹435
• 4 × VIYONA 401 single pole MCBs: ₹580

That is ₹2,105 before the RCCB, wire and labour, and with the RCCB fitted leaves two ways spare. A 442 isolator (₹230) can take the main’s place only where the supply cable is already protected at the meter. The VIYONA 401 to 433 MCBs are made to IS/IEC 60898-1 under BIS licence CM/L-2544151; see the VIYONA 10 kA MCB page. Our isolator switch page explains when an isolator can be the main.

Mistakes people make with double door boards

The doors solve one problem and invite a few others:

• Inner door left off: the board is then no safer than an open one.
• Outer door blocked: furniture or stock stacked in front of it.
• Unlabelled breakers: behind two doors, nobody remembers which is which.
• No spare ways: the cheapest ways are the ones bought on day one.

The inner door matters most. Electricians sometimes leave it off after a job “to make the next visit quicker”. Put it back every time: it is what keeps a shop assistant’s fingers away from the busbar.

For routine checks on any DB, see our home electrical maintenance checklist.

Double door MCB box price and packing

Our single phase double door boards run from ₹750 (381, 4 way) to ₹1,410 (386, 16 way); TPN double door boards from ₹2,620 to ₹3,350. All are packed 10 per box and sold in full boxes only through dealers; a box of ten 385s is ₹12,100 at MRP.

Contractors fitting out a building buy by the box; a shop owner buys one board from a dealer. Every box and breaker we make is in our MCB price list.

Fitting a double door board

A double door board needs room to swing its outer door fully open. Before fixing it, check that the hinge side is not tight against a wall corner, a shelf or a door frame; a door that opens only halfway makes every breaker reset awkward and tempts people to leave it open for good.

Mount it at a height where the MCB levers sit at about adult chest height, close to where the supply enters the premises, and on a dry wall. Plan the conduit entries before the wall is finished, one route per outgoing circuit, and keep the incoming supply cable on its own entry.

Inside, the inner door should go back on with every screw. Mark each slot on the inner door with its circuit name. Our switch board height guide covers mounting heights room by room.

Double door boards in a housing society

Common-area boards are where double door construction pays for itself. A lift lobby, a stair well, a pump room or a parking level board is opened by watchmen, housekeeping staff and visiting technicians, often in poor light. The inner cover keeps all of them away from live parts while still letting them reset a tripped breaker.

A typical small society might use a 10 way board (384, ₹1,090) per floor lobby for lights and sockets, counted by the same rule, and a separate board in the pump room. Pumps on a three phase supply need a TPN board; our MCB for water pump guide sizes the pump breaker.

Where we supply

Everything on this page is made at our works in Marol, Andheri East, Mumbai, and sold through dealers across Maharashtra and in many other states. See where we supply in Maharashtra and how we supply the rest of India. Orders placed through our office are delivered all over India, in full boxes only.