Power equipment design
Working documentation: from 22 days
Price from 50000 roubles
We develop projects of power electrical equipment of any complexity - from selecting the optimal power supply circuit to calculating loads and protection, ensuring uninterrupted and safe operation of the facility under real operational load.
We carry out the design of power electrical equipment, including power calculations, selection of protection devices and generation of connection diagrams. We create solutions that ensure reliable operation and stable operation of power electrical equipment systems in industrial and civil construction. A competent design can reduce the likelihood of emergency conditions, increase energy efficiency and ensure correct operation of the equipment throughout its service life.
Why does the reliability of the entire electrical system of a building depend on the design of power equipment?
Power electrical equipment is the distribution infrastructure of a facility: main switchboards, input devices, distribution points, busbars and power assemblies, through which electricity is distributed from the power source to each consumer. An incorrectly calculated load on the main switchboard section, an incorrectly selected circuit breaker, or an underestimated peak current when starting electric motors - and the site experiences false protection triggers, overheating of cables and emergency shutdowns, which are much more expensive to eliminate after construction is completed than to prevent at the DD stage.
AYU-Project develops a complete set of design documentation and working documentation for power electrical equipment for residential, commercial and industrial facilities - with a reasonable choice of circuit solutions, accurate calculations of loads and protective equipment and documentation ready for examination.
What is included in the concept of “power electrical equipment” of a building?
Power electrical equipment is the entire infrastructure for receiving, distributing and supplying electricity from the point of entry into the building to the terminals of power consumers: process equipment, elevators, ventilation, pumps, air conditioners and other engineering systems. This concept does not include control and automation circuits, extra-low-voltage systems and lighting - they are designed in separate sections. Power equipment is the “skeleton” of the internal power supply system, on the correct design of which the operation of everything else depends.
What types of power equipment do we design?
As part of the development of design documentation and working documentation for power electrical equipment, AYU-Project designs the entire distribution infrastructure of the facility:
The main distribution board (MSB) is the central node of the building's internal electrical system, receiving power from a transformer substation or city cable line and distributing it along the main lines. Includes input devices, bus partitioning, outgoing line devices, current transformers for metering, ATS devices if there is a backup input.
Input distribution device (MDB) - for facilities with direct power input with 0.4 kV. Performs the functions of input, commercial accounting and primary load distribution. It is designed taking into account the calculated input current, the number and power of outgoing lines, the metering scheme and the requirements of the network organization.
Distribution points (distribution point) and power assemblies are intermediate distribution devices installed in technical rooms of floors or production areas. They receive power from the main lines MSB/MDB and distribute it along group lines to consumers.
Busbar trunking (bus trunking) - for facilities with high load density and the need for flexible connection of consumers: trading floors, production workshops, data center. Designed as main (from MSB to floor distribution point) and distribution (in the consumer area with branch blocks).
Power supply panels for technological equipment are specialized distribution devices for individual systems: elevator facilities, ventilation and air conditioning, pumping units, food production equipment, technological lines.
How are electrical loads calculated and protective equipment selected?
Calculation of electrical loads is the foundation of a power equipment design: cable cross-sections, ratings of circuit breakers, power of transformers and throughput of switchboards depend on its accuracy. AYU-Project engineers perform calculations using the ordered diagram method in accordance with RTM 36.18.32.4-92 And SP 31-110-2003, sequentially determining the loads from the group distribution level to the input device.
The design part of the power equipment project includes:
- Calculation of electrical loads - determination of the calculated current for each line and node, taking into account demand, power and simultaneity factors. The starting currents of electric motors are calculated separately, influencing the choice of protective devices;
- Calculation of short circuit currents (SCC) - for each distribution level: from the main switchboard buses to the most remote load points. The results are checked under two conditions: the sufficiency of the breaking capacity of the circuit breakers and the sensitivity of the protection in single-phase short circuit mode;
- Selection and testing of protective devices - circuit breakers, fuses, RCD and RCBO are selected according to rated and rated currents, starting currents, conditions for coordination with cable lines and electrical safety requirements;
- Selection of cross-sections of cables and wires - based on permissible heating, taking into account installation conditions, reduction factors and checking for permissible voltage loss;
- Reactive power compensation - if necessary: calculation and selection of capacitor banks to reduce the reactive component of the load and reduce tariff surcharges for reactive power.
What is included in design documentation and working documentation power equipment?
Documentation for power equipment is developed in accordance with Government Decree of the Russian Federation No. 87 dated 16.02.2008 No. 87 (as amended on 21.10.2025) “On the composition of sections of design documentation and requirements for their content” and requirements GOST R 21.614.
Design documentation stage includes: an explanatory note describing the adopted circuit solutions, justification for the choice of power supply and redundancy circuits, characteristics of the main equipment (MSB, MDB, busbars), basic single-line power supply diagrams, calculation part, description of electrical safety measures.
Working documentation stage contains: circuit and wiring diagrams of MSB, MDB, distribution point and power panels; plans for the location of power equipment with reference to construction axes; diagrams for laying trunk and group cable lines; cable magazines; specifications of equipment and materials. The volume and composition of WD is agreed with the customer upon conclusion of the contract.
Regulatory framework for the design of power electrical equipment
Power equipment of buildings is designed in strict accordance with the current regulatory and technical framework, covering both technical requirements for equipment and calculation methods and safety rules:
- PUE (7th edition): chapters 3.1, 3.2 - protection and automation; Chapter 7.1 - electrical installations of residential and public buildings; Chapter 7.2 - electrical installations of industrial buildings;
- GOST R 50571 - a series of standards for low voltage electrical installations;
- GOST R 51321 - low-voltage complete devices (low-voltage switchgear), requirements for switchboards;
- SP 256.1325800.2016 “Electrical installations of residential and public buildings”;
- SP 31-110-2003 “Design and installation of electrical installations of residential and public buildings”;
- RTM 36.18.32.4-92 “Instructions for calculating electrical loads”;
- GOST R 21.614-2021 “System of design documentation for construction. Rules for the implementation of working documentation for power electrical equipment";
- Government Decree of the Russian Federation No. 87 dated 16.02.2008 No. 87 (as amended on 21.10.2025) “On the composition of sections of project documentation and requirements for their content” - regarding the composition of design documentation.
For which facilities do we design power equipment?
AYU-Project carries out the design of power electrical equipment for all types of capital construction projects - from multi-apartment residential buildings with underground parking lots to large industrial enterprises with an extensive distribution infrastructure. Priority areas in the B2B segment:
- Residential complexes - MSB with apartment distribution, MDB sections, power supply for elevators, IHS, pumping units and common areas;
- Shopping and office centers - distribution by rental zones and engineering systems, busbars for flexible layout of the sales area;
- Manufacturing enterprises - power supply of technological lines, electric motors of pumps, compressors and ventilation; calculation of starting currents and reactive power compensation;
- Logistics and warehouse complexes - zoned power supply with the possibility of phased connection of sections;
- Medical institutions and data center are objects of the first reliability category with increased requirements for the redundancy scheme and power restoration time.
Why do construction companies trust AYU-Project to design power equipment?
Power equipment is one of the most voluminous and detailed sections in the design of internal power supply: a large number of switchboards, a significant volume of cable logs and specifications, stringent requirements of installation organizations for the accuracy of drawings. This is where the cost of negligence in WD is most noticeable.
Technical knowledge confirmed by practice. Implemented projects for Russian Railways, PJSC Rosseti Siberia, FGC and a number of federal departments mean that our engineers have gone through the school of facilities with the highest requirements for the composition and accuracy of documentation.
Working documentation that can be used for immediate installation. The working documentation developed by AYU-Project contains all the data necessary for procurement and installation, without “blank spots” in cable logs and specifications - which is critical for the contractor who plans to supply equipment.
Single responsibility for the entire electrical section. Power equipment is designed in conjunction with transformer substations, metering and lighting systems, relay protection and automation systems - without technical contradictions at the interfaces.
Standards and requirements for designing power equipment
There are a number of standards and design requirements that must be met in order for power equipment to be approved by regulatory agencies prior to installation or use. The regulations concern:
- test procedures to ensure accuracy and reliability under normal operating conditions;
- calculation methods that take into account the distribution of load between various components;
- noise level;
- methods of insulating wires or cables;
- recommendations for TO;
- installation instructions;
- local and industry regulations.
Our engineers have sufficient technical knowledge and experience to successfully cope with the development of any power electrical equipment.
Fixed Schedule and Price are enshrined in the contract and are not revised during the work process.
Cost of designing power equipment
The price for developing design documentation and working documentation is determined individually: the type and purpose of the facility, the total installed capacity, the number of switchboards and distribution points, the presence of busbars and ATS circuits, as well as the list of stages being developed - DD, WD or a complete set. An approximate calculation is available through the online calculator on the website. An accurate commercial proposal is formed after analyzing the initial data - free of charge, within one business day.
How to order a power equipment project from AYU-Project?
Leave a request on the website or call us: briefly describe the object, its type, area, purpose and availability of initial data - architectural solutions (AR/AS), technological specifications, specifications for power supply. Attach existing documents - this will speed up the formation of an accurate proposal. The initial consultation is free, and we work across Russia remotely.
How to order the design of power equipment: stages of work
- Submit an enquiry - the initial consultation is free
Form on the website or phone: +7 (383) 375-73-77 / +7 (923) 743-73-77. Briefly describe the object: type, area, purpose, availability of initial data (AR/AS, technological specification, technical specifications for power supply). Attach existing documents - this will speed up the formation of an accurate proposal. - Receive a Commercial Proposal Within 1 Business Day
CP with the scope of work (DD, WD or a complete set), cost and deadlines. The price is fixed in the contract and is not revised during the work process. - Provide the initial data and sign the agreement
Architectural solutions (AR/AS), technological specifications with a list of power consumers, specifications for power supply, data on the reliability category of the facility and the redundancy scheme. The contract fixes the scope of work, cost and timing. - Calculation part: loads, TKZ, selection of protective equipment
Calculation of electrical loads using the method of ordered diagrams (RTM 36.18.32.4-92), calculation of short-circuit currents for all distribution levels, checking the consistency of protective devices, selection of cable sections. If necessary, calculate reactive power compensation. - Development of circuit solutions and equipment composition
Schematic single-line diagrams of main switchboards, ASU, RP and power panels with the choice of type and composition of equipment. Busbar diagrams, power equipment layout plans, main cable lines laying diagrams. - Preparation of DD and Expert Review Support
Set DD according to Government Decree of the Russian Federation No. 87 dated 16.02.2008 No. 87 (as amended on 21.10.2025): explanatory note, single-line diagrams, calculation part, equipment characteristics. Support of state or independent expert review; comments will be addressed within the agreed scope at no additional cost. - Issue WD and transfer to the customer
A complete set of WD to GOST R 21.614-2021: installation diagrams of panels, layout plans linked to building axes, cable logs, specifications of equipment and materials. We deliver in PDF and DWG formats. Author's supervision - by agreement.
Our Advantages
How We Work
Frequently Asked Questions
Yes. We will need design documentation on power supply, single-line diagrams, load calculations and TKZ from the design documentation, as well as architectural solutions in the current edition. We develop detailed design documentation with adjustments to technical solutions when comments are identified in the provided design documentation.
PD (design documentation) is developed for expert review: it contains an explanatory note with justification of circuit solutions, basic single-line diagrams, calculation part (loads, TKZ, protection), characteristics of the main equipment. RD (working documentation) is created for installation work: includes installation diagrams GRShch, VRU and RP, equipment location plans with reference to building axes, cable laying diagrams, cable logs and specifications with accuracy sufficient for direct purchase and installation.
Main regulatory documents: PUE (7 edition) - chapters 3.1, 3.2 (protection and automation), 7.1 (residential and public buildings), 7.2 (industrial buildings); GOST P 50571 - a series of standards for low voltage electrical installations; GOST R 51321 - requirements for low-voltage complete units (NKU); SP 256.1325800.2016 - electrical installations of residential and public buildings; SP 31-110-2003 - design and installation of electrical installations; RTM 36.18.32.4-92 - calculation of electrical loads; GOST R 21.614-2021 - rules for the execution of working documentation for power electrical equipment; Russian Government Resolution No. 87 dated 16.02.2008 N 87 (as amended on 21.10.2025) - composition of the design documentation.
For a standard administrative or residential building with an area of up to 10 000 m² - from 4 to 8 weeks. For large industrial facilities or multifunctional complexes - individually, depending on the composition of the equipment and the number of switchboards. The terms are fixed in the contract.
Yes, if the facility contains significant loads with a low power factor (electric motors, welding equipment, lighting based on ballasts), we perform reactive power calculations and, if economically feasible, design capacitor units. This reduces the contractual penalty for reactive power and reduces the current load on the supply lines.
Yes, calculating short-circuit currents and checking the consistency of protective devices is a mandatory calculation part of the power equipment design. Based on the results of these calculations, circuit breakers are selected and settings are determined, which directly affects the safety and reliability of the system.
Yes. We will need design documentation on power supply, single-line diagrams, load calculations and TKZ from the design documentation, as well as architectural solutions in the current edition. We develop detailed design documentation with adjustments to technical solutions when comments are identified in the provided design documentation.
Power equipment is the entire infrastructure for receiving and distributing electricity: main switchboards, ASUs, distribution points, busbars, power assemblies and cable lines to power consumers. Lighting, fire alarms, SCS and other low-current systems are designed in separate sections. We carry out both the power equipment section separately and a complete set of electrical sections.
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