Electrical & Lightning Safety
Sub-station, MDB and SDB Panel Installation in Bangladesh
A sub-station steps utility power down from 11 kV or 33 kV to the 400 V a building uses, then the main distribution board (MDB) and sub-distribution boards (SDBs) share it out to floors and machines. Each part must be sized for the real load, protected by correctly rated breakers and installed with safe clearances.
Quick facts
- Standards
- BNBC 2020 Part 8, IEC 62271, IEC 60076, IEC 61439, IEEE 80
- Who needs it
- New factories and buildings, load expansions, sites with old or overheating panels
- What you get
- A designed, supplied, installed and tested sub-station and distribution system, with drawings
- Equipment
- HT VCB or LBS panels, transformer, LT panel with ACB, PFI panel, ABB or Schneider breakers
Scope
What’s included.
Everything below is done by our own engineers and installation team, so one company answers for the result.
- Load calculation and transformer sizing
- HT switchgear with VCB or load break switch
- Distribution transformer, oil-immersed or dry-type
- LT panel with ACB incomer and outgoing feeders
- Power factor improvement (PFI) panel
- MDB and SDBs built and verified to IEC 61439
- Sub-station earthing, cable trenches and bus ducts
- Pre-energization tests and utility documentation
How is a sub-station sized?
Sizing starts with the connected load of every machine, light and air conditioner, then applies demand factors, because not everything runs at once. Growth is added as a stated margin, not by rounding up. The result sets the transformer rating in kVA, the supply voltage to request from the utility, and the size of the LT incomer and busbars.
Getting it wrong is expensive in both directions. An undersized transformer runs hot and trips at peak production. An oversized one costs more to buy and wastes energy in no-load losses every hour it is energized. We show the calculation in writing so your engineers and the utility can check it.
What makes a distribution board safe?
A safe MDB or SDB is a verified assembly, not a box of breakers. IEC 61439 requires the panel's design to be verified for temperature rise, short-circuit withstand, clearances and creepage, so the board carries its rated current without overheating and withstands the fault level where it is installed.
On site, we check that each breaker rating matches the cable it protects, that breaking capacity suits the fault level at that point, and that busbars, neutral and earth bars are sized correctly. Every outgoing circuit is labeled to the single line diagram. Panels get clear front access, an insulating mat and a lockable door.
Can old panels be upgraded instead of replaced?
Sometimes. If the enclosure and busbars are sound, replacing worn breakers, adding proper incomer protection and re-terminating cables can bring a panel up to standard for less than a new board. If the busbars are too small for today's load, the enclosure is open or damaged, or there is no room to separate circuits safely, replacement is the honest answer. A thermographic scan usually settles it.
How it’s done
How we deliver it, step by step.
- 01
Load survey
We list every existing and planned load, then calculate maximum demand with your engineers.
- 02
Design and documents
SLD, room layout and equipment schedule agreed, and documents prepared for the utility application.
- 03
Supply and inspect
Switchgear sourced to the agreed brands; panels inspected against drawings before delivery.
- 04
Install and terminate
Our team sets equipment, lays cables, builds the sub-station earth and terminates every circuit.
- 05
Test and energize
IR, earth, transformer ratio and protection tests, then a planned energization with the utility.
Price guide
What sets the price.
Every site is different, so we price from a survey, not a rate card. These are the factors that move the number, and the written quote shows each one.
- Transformer rating and supply voltage, 11 kV or 33 kV
- Switchgear type and brand, such as ABB or Schneider
- Number of MDB and SDB panels and outgoing feeders
- Cable sizes and lengths between sub-station and panels
- Civil work for the sub-station room, trenches and plinths
- Reuse of existing equipment versus full replacement
Service areas
Sub-station & MDB/SDB in Chattogram, Dhaka, Gazipur and Narayanganj.
Our engineers survey, install and maintain on site across these cities and the industrial zones around them. For a site elsewhere in Bangladesh, ask and we will tell you plainly whether we can cover it.
- Chattogram
- Dhaka
- Gazipur
- Narayanganj
Frequently asked questions
The transformer rating drives most of the cost, followed by the HT switchgear type, the brands specified, the number of distribution boards and the cable lengths. Civil work and utility connection charges add to it. We price after a load survey and give an itemized quote, so you can see what each part costs and where cheaper options exist.
It depends on maximum demand, not the sum of every nameplate. We add up connected loads, apply realistic demand factors for your type of production, then add a stated margin for growth. The answer is a transformer rating in kVA, shown with the working so the utility and your engineers can confirm it.
A power factor improvement panel uses capacitor banks to offset the reactive power drawn by motors and other inductive loads. Bangladeshi utilities can charge penalties when power factor falls below their required level, so most factories with motor loads need one. Automatic panels switch capacitor steps in and out as the load changes.
NFPA 70B sets out a maintenance program for electrical equipment based on its condition and how critical it is. For factory panels, that typically means cleaning, tightening and inspection at least once a year, plus a thermographic scan under load. Panels in dusty or hot areas, or with past hot spots, need closer intervals.
Know your building is safe. Book in 60 seconds.
Tell us what you need and where. An engineer confirms your survey slot by phone or WhatsApp.
What happens next
- 1
We call or WhatsApp you to confirm a time.
- 2
An engineer visits and assesses your fire, electrical and security risks.
- 3
You get a written recommendation and quote. No charge, no obligation.
Your details stay private. No newsletters, no sales sequences.