KTPBM 10/0.4 Block-modular prefabricated transformer substations up to 2500 kVA

KTPBM 10/0.4 kV up to 2500 kVA are block-modular, factory-built transformer substations for receiving, converting, and distributing three-phase AC power at 50 Hz, with nominal voltage classes 6/10 kV on the medium-voltage (MV) side and 0.4 kV on the low-voltage (LV) side. KTPBM units are assembled from standardized modules (MV switchgear, transformer module, LV switchgear), supplied with a high degree of factory completion, and aimed at fast deployment for industrial, agricultural and infrastructure sites, remote oil & gas pads, residential developments, and municipal utilities.

The block-modular architecture enables scalable ratings (100…2500 kVA), flexible MV line entry (overhead/cable), transformer types (hermetically sealed oil-filled or dry-type cast-resin), and configurable 0.4 kV outgoing feeders. Modules are designed in accordance with IEC/EN requirements and applicable local codes, provide safe access and maintenance, and allow upgrades (additional LV bus sections, ATS, reactive-power compensation, AMI/SCADA, etc.).

Purpose and applications

KTPBM are intended for:

receiving power from 6/10 kV distribution networks and converting it to 0.4 kV to feed LV distribution systems;
establishing power supply centers at industrial facilities (shops, process lines, compressor stations, admin/utility buildings) and infrastructure sites (retail, logistics and agro complexes, housing & utilities);
powering remote sites: drilling and well pads, booster pump stations, oil/gas treatment units, production and processing facilities;
construction and expansion of residential areas, townships, cottage/holiday communities, agricultural enterprises and farms;
temporary/mobile power supply for construction, retrofit and emergency-restoration works, with the option to relocate the substation to another site.

Compared with traditional “kiosk” or “container” substations, KTPBM offer a higher degree of factory completion, shorter on-site installation time, true modularity for staged capacity growth, improved maintainability, and a standardized platform that simplifies spares and service procedures.

Technical data

Power rating of distribution transformer, kVA	100 – 2500
Nominal voltage on MV side, kV	6; 10
Nominal voltage on LV side, kV	0.4
LV main busbar current, kA	0.16 – 3.61
MV thermal withstand current, kA (1 s)	16; 21; 25
MV peak (dynamic) withstand current, kA	51
LV thermal withstand current, kA (1 s)	10 – 50

Service conditions

KTPBM 10/0.4 kV up to 2500 kVA are designed for operation under the following conditions:

installation altitude - up to 1000 m a.s.l.;
ambient temperature ranges by environmental class per EN/IEC 60721-3-4 (stationary, non-weather-protected locations) and EN/IEC 60721-3-3 (stationary, weather-protected locations):
- non-weather-protected: -45 °C…+40 °C (typical);
- extended low-temperature option: down to -60 °C…+40 °C (project-specific).
industrial, non-explosive, non-corrosive atmosphere; allowable rime-ice thickness up to 20 mm;
wind pressure per the designated wind-load region and enclosure design;
degree of protection - not less than IP34 per IEC 60529 (transformer compartment may differ per project);
outdoor installation (category “1”); mounting on a base slab, FBS blocks, or a compacted pad as defined by the installation plan.

KTPBM are not intended for hazardous (explosive) atmospheres, areas with intense vibration/shock, or for back-feeding from the LV side. Additional requirements for seismic performance, lightning protection, coating corrosion resistance, and snow/ice loads are set by the project and confirmed by calculations and test reports.

Layout and design solutions

Classification of KTPBM:

By transformer type	– oil-filled – dry-type
By neutral earthing of the LV transformer winding	– solidly earthed (TN)
By number of transformers	– single-transformer – dual-transformer
Busbar insulation in LV switchgear	– bare busbars
MV line entry	– cable – overhead
LV terminations in switchgear	– top entry – bottom entry
By environmental/location class	– EN/IEC 60721-3-4; EN/IEC 60721-3-3
Insulation coordination per IEC 60071-1	– standard for the given voltage class
By feeder arrangement	– through (pass-through) – terminal (dead-end)
By LV panel function	– feeder panels

Modular structure. KTPBM are built from standardized blocks: MV switchgear (6/10 kV cubicle(s)), transformer module (one or two transformer bays), and LV switchgear (0.4 kV panels). The blocks are mounted on a common base frame. Depending on rating and feeder count, LV panels may be arranged in one or two rows; LV busbars can be sectionalized with a bus tie circuit breaker.

Transformer(s). Distribution transformers 100…2500 kVA: hermetically sealed oil-filled (e.g., TMG-type or equivalents) or dry-type cast-resin (for enhanced fire safety/indoor or enclosed operation). Typical vector groups - Y/Y_n-0 or Δ/Y_n-11; losses and energy-efficiency class - per specification/IEC. The transformer bay provides ventilation and enclosure fault-containment capability per the calculated short-circuit levels and type-test evidence.

MV switchgear (6/10 kV). MV side solutions may use metal-clad/metal-enclosed switchgear or modular cubicles with load-break switches and/or vacuum circuit breakers (per project). Options include:

overhead MV line entry - connection via pole-top/roof disconnector and surge arresters, with through-feed (pass-through) or without (terminal);
cable MV entry - via terminations/bus sections in the MV cubicle; a pass-through MV section for line transit is available;
transformer protection - MV fuses with load-break switch, or a circuit breaker with relays (for higher fault levels/availability categories).

LV switchgear (0.4 kV). Incoming devices - molded-case/air circuit breakers (fixed or withdrawable); on request - ATS and LV bus sectionalizer. Outgoing feeders - molded-case breakers or switch-disconnector-fuse units. Busbars - copper or aluminum (e.g., AD31T), with anti-corrosion/fretting protection on contact surfaces; cross-sections selected by continuous current and thermal withstand with load growth margin. The package may include active/reactive energy metering, supervision (A/V), auxiliary services, 40/63 A utility sockets, and a street-lighting cubicle (manual/auto).

Enclosure and coating. Welded frame and sheet-steel panels 2.0–2.5 mm (doors, walls, roof). For enhanced corrosion resistance - hot-dip galvanizing plus powder coating. Degree of protection - IP34 for MV/LV sections; the transformer bay may differ (per project). Doors gasketed; hinges guarded; ventilation louvres with mesh; key/hasp locks; safety signage.

Access and maintenance. Each compartment has its own door/gate providing safe access for inspection, MV fuse replacement, and LV device service. A dual-transformer module is partitioned into bays and fitted with roll-in/roll-out gates, lifting lugs, and removable floor/rails.

Factory completion and logistics. Modules are fully assembled and wired at the factory, with settings and routine electrical tests per the QA plan. Delivery - as a single assembly or as separate modules/sections for transport, with an installation kit and O&M manual. The base frame has marked holes for anchors/cable entries; for overhead LV take-offs - brackets and corner boxes are provided.

Most requested configurations by rating

Typical selections for frequent use-cases. Values are indicative and finalized by data sheet and project design.

Rating, kVA	MV line entry	KTPBM arrangement	Transformer	LV switchgear (type)	Typical applications
250	Cable	Terminal	Oil/dry-type	1 incomer, up to 6 feeders	Small enterprises, farms, utility service sites
400	Overhead	Pass-through	Oil-filled	Bus sectionalizer, 8–12 feeders	Logistics parks, townships
630	Cable	Terminal/pass-through	Oil/dry-type	Withdrawable incomer, 10–16 feeders	Industrial sites, substations for residential areas
1000	Cable	Pass-through	Oil-filled	Bus sections, 12–20 feeders	Shopping/business centers, plant buildings
1600	Cable	Pass-through	Oil-filled (2×800) or 1×1600	ATS, 16–24 feeders	Oil & gas facilities, industrial parks
2×1000	Cable	Dual-transformer with ATS	Oil/dry-type	Sectionalized + bus tie	Category I loads, critical consumers
2500	Cable	Terminal/pass-through	1×2500 or 2×1250	Incomer/section CB, 20+ feeders	Large manufacturing, hubs, data-center nodes

Safety and interlocking

KTPBM are fitted with electrical and mechanical interlocks preventing access to live parts with devices closed, avoiding mal-operations, and ensuring safe isolation for maintenance: door position contacts, switch/disconnector mechanical key interlocks, and control-circuit electrical interlocks. LV circuits include RCD/RCBO for lighting and socket feeders, and logic to block closing of a bus-tie when incomers are not synchronized (ATS/AR logic per project).

Protections include: surge protection against lightning and switching overvoltages (MV/LV surge arresters), MV short-circuit and transformer overload/fault protection (MV fuses or circuit breaker overcurrent protection; gas relay for ≥ 1000 kVA where applicable), and protection of auxiliaries and LV outgoing feeders. Enclosure fire performance and fire-stopping of cable entries - per project design and fire-safety rules.

Versions and options

MV scheme: terminal/pass-through; single-bus or with line transit capability; with load-break switch or circuit breaker.
Number of transformers: single or dual; for Category I - 2×T with ATS and LV bus tie.
Environmental execution: EN/IEC 60721-3-4 / EN/IEC 60721-3-3; optional insulated walls/floor, LV compartment heating, enhanced anti-corrosion coating, snow guards.
Metering & automation: AMI/energy metering for active/reactive energy; telecontrol and remote monitoring (doors, temperature, faults, device positions).
Power quality: PFC banks (manual/automatic), detuned reactors, harmonic filters (per spec).
LV entry/exit: cable/overhead, top/bottom entry, utility sockets, main/backup schemes.
Additionally: seismic kit, lightning protection, CCTV/ACS, smoke/temperature sensors, transformer thermal monitoring, anti-condensation heaters with thermostat.

Standards compliance

EN/IEC 60721-3-4 / EN/IEC 60721-3-3 - environmental classes for stationary use (non-weather-protected / weather-protected);
IEC 60529 - degrees of protection (IP code);
IEC 62271-200 (as applicable to MV switchgear) and related IEC 62271 series;
IEC 62271-202 - prefabricated/compact secondary substations (as applicable to the enclosure concept);
IEC 60071-1 - insulation coordination by voltage class;
IEC 61000-4-30 - power-quality measurement (for AMI/monitoring, where specified);
IEC 60364 (and applicable national wiring/electrical codes) - LV electrical installations.

Partnering with contractors and manufacturers

We welcome cooperation with mechanical/electrical manufacturers, assembly plants and investors interested in producing block-modular KTPBMs. We offer:

a full manufacturing drawing package and process sheets tailored to your capacity;
adaptation of drawings to available machinery/equipment and regional supply specifics;
support for pre-production (PPI), training of assemblers, audit of control operations and routine tests;
sourcing support for metalwork, coating, busbars, cabinets, and procurement of instruments/MV gear;
costing and export options (EAEU), certification support.

Documentation offered (for manufacturing and tenders)

Preliminary technical data and technical proposal for bidding: scope of supply, schematic solutions, key component specs, data sheets.
Manufacturing drawings and 3D models: DWG/DXF (AutoCAD), SLDPRT/SLDASM (SolidWorks), Parasolid (x_t), BOMs and material take-offs.
Installation/O&M manuals, test programs and procedures, electrical checklists, installation method statements.
Document tailoring to project requirements and your plant capabilities.
If required - engineering of compatible assemblies for third-party equipment already installed on site.

Why work with us

- No need to maintain a large in-house design staff - you receive a drawing set that a mid-level engineer can confidently build from.
- No protracted prototyping - proven deployment practices enable series production without long pilots.
- When building to our documentation - consulting and support on all nuances of KTPBM 10/0.4 kV up to 2500 kVA at every stage.