KTPM - Pole-mounted complete transformer substation 6(10)/0.4 kV

Purpose and application

KTPM (pole-mounted complete transformer substation) - a factory-built module ready for installation, designed to receive medium-voltage power at 6 or 10 kV, step it down to 0.4 kV, and distribute it through LV outgoing feeders. The outdoor substation is mounted on two reinforced-concrete poles and includes an MV section, a power transformer (oil-immersed or dry-type on request), and an LV switchboard. KTPM is used in radial distribution networks to supply agricultural facilities, municipal infrastructure, small industrial sites, cottage communities, construction sites, and outdoor lighting. Thanks to factory completeness and standardized layout, KTPM enables fast commissioning, minimal site works, and low total cost of ownership.

Connection to a 6-10 kV overhead line is typically made via a pole-mounted load break switch or disconnector with earthing blade on the nearest pole, providing safe visible isolation and lockable drives (per IEC 62271 series). On the 0.4 kV side, outgoing feeders with circuit breakers are formed, a dedicated lighting feeder is provided, and a commercial metering unit is installed. A heated metering compartment for cold climates is available.

Technical data

Parameter	Typical value
Rated voltages	MV: 6 or 10 kV; LV: 0.4 kV; frequency 50 Hz
Power range	25; 40; 63; 100; 160; 250 kVA
Environmental conditions / installation	Outdoor installation; environmental conditions per IEC 60721. Cold-climate package available.
Operating temperature range	from -45...-60 °C to +40...+45 °C (depends on series and options, tests per IEC 60068)
Altitude above sea level	up to 1000 m
Relative humidity	up to 80 % at +25 °C
MV short-circuit withstand (approx.)	thermal up to 16 kA (1 s), dynamic up to 20 kA (peak)
Degree of enclosure protection	IP23...IP43 per IEC/EN 60529 (final value per specification)
LV outgoing feeders	3-4 outgoing lines + lighting feeder
LV incomer device	switch-disconnector or circuit breaker (IEC 60947-3 / IEC 60947-2)
Energy metering	commercial, three-phase, MID-compliant per EN 50470 (optional heated compartment)
MV network connection	via pole-mounted LBS or disconnector with earthing per IEC 62271-102/-103 on the nearest 6-10 kV pole

Note: exact parameters (feeder currents, enclosure IP, spare parts kit, fuse and breaker types, dimensions and mass) depend on the series and manufacturer and are fixed in the enquiry sheet and supply specification.

Layout and design

The KTPM architecture is a frame mounted on two RC poles, hosting three key sections: MV 6(10) kV, power transformer, and LV 0.4 kV. Interconnections are short and accessible for simplified installation and inspection. Components follow European standards: MV bushings and insulators, surge arresters per IEC 60099-4, HV current-limiting fuses per IEC 60282-1; on the LV side - bus links, MCBs/MCCBs per IEC 60898-1/IEC 60947-2, protective and switching devices per IEC 60947, and metering per EN 50470. All doors and drives have mechanical-electrical interlocks; MV interlocks prevent incorrect operations when the earthing switch is engaged.

Section	Composition and features	Options
MV 6(10) kV	overhead line entry, through-bushings, HV fuses per IEC 60282-1, ZnO surge arresters per IEC 60099-4, interlocks per IEC 62271	cable entry, measuring CTs/VTs, alarm and remote indication
Power transformer	oil-immersed distribution transformer or dry-type on request, per IEC 60076; vector group per specification	oil level and temperature sensors, space heaters
LV 0.4 kV	incomer (switch-disconnector or CB), 3-4 feeders, lighting feeder, metering unit per EN 50470	ATS, bus sectioning, remote indication, heated metering
Base and poles	frame for RC poles, crossarms and brackets for ABC (aerial bundled conductors)	adapter plates, custom embedded parts, enhanced corrosion protection per ISO 12944
Safety	mechanical and electrical interlocks, earthing studs, safety signage	padlocks, limit switches, dry contacts

Typical configurations

Designation	Application and load	LV switchgear contents	Connection	Notes
KTPM-25/6(10)/0.4	local loads: first-aid post, shop, pump, small farm	2-3 LV feeders + lighting	MV overhead entry via pole LBS or disconnector; LV - cable or ABC	minimal footprint and mass; IP per specification
KTPM-100/6(10)/0.4	village or workshop loads of medium power	3-4 feeders, optional bus sectioning	pole LBS/disconnector on MV pole; LV - cables and/or ABC	oil-immersed transformer 100 kVA per IEC 60076
KTPM-250/10/0.4	distribution to 3-4 feeders + lighting	typical currents: 80/100/160/250 A; lighting 16 A	MV entry via LBS with earthing; LV - combined	ZnO surge arresters and HV fuses, interlocks and locks

Important: to ensure thermal and dynamic withstand of connections between the pole LBS and the MV section, select conductor cross-sections (ABC or aluminium bars) by calculated short-circuit currents and manufacturer data. All values are finalized in the technical specification.

КТПМ - Комплектная трансформаторная подстанция мачтового типа

We provide documentation to set up your own KTPM 6(10)/0.4 kV production

A complete engineering package to launch pole-mounted complete transformer substations at your site - from tender participation to stable serial assembly.

What is included

- Pre-tender bundle: product technical description with power range 25-250 kVA and configuration options, single-line and schematic diagrams, layout sketches, enquiry forms, high-level BOM, and a letter confirming production readiness.
- Full production drawing set: fabrication drawings for the frame, MV and LV sections, brackets and fasteners, purchased parts lists, detailed BOMs and consumption tables, routing cards, assembly and adjustment instructions, and 3D models (STEP/Parasolid) for CNC and fit checks.
- Process package: welding and machining cards, list of jigs and templates, inspection operations and measurement sheets, FAT procedures, typical device settings, and recommendations on RC poles, earthing system, and cable or ABC routing.
- Fast adaptation to your shop and project: outdoor rating per IEC/EN, LV execution (cable or overhead), feeder quantity and currents, enclosure IP per IEC 60529, metering and automation cabinet layout, and dimensions tailored to your equipment and transport limits.
- Transition and integration: adapters for compatibility with existing 6-10 kV pole switches, interfaces to existing LV switchboards and third-party metering cabinets, and phased replacement solutions for legacy substations with minimal downtime.

Note: the composition and volume of documentation are defined individually for each customer.

Why it is convenient and cost-effective

- No need to keep a large engineering staff: the drawing structure and comments target an engineer of average qualification, while complex nodes include step-by-step instructions.
- Rapid ramp-up without lengthy prototypes: proven circuit and mechanical solutions, unified assemblies, typical interconnections and fasteners - fewer risks and a shorter launch cycle.
- Support until stable production: we advise your teams on layout, procurement, and process, review purchase requests, provide method statements for installation and commissioning, supervise assembly and start-up of the first unit, and refine documents based on pilot results.