Technical Communication in Power Systems

By Udit Chaudhuri

This article is inspired by posts under the same subject-line on the TWIN (Technical Writers of India) list, predominated by a force of young and enthusiastic technical writers servicing the IT industry. One poster wondered what manual could be written for this field, since all equipment and systems are automatic! Another ventured to integrate the various areas of electronics involved in power systems.  

Power ratings begin with a few watts and run up into megawatts. Here we use a variety of documentation, first to assist the customer in defining a requirement, then to select a product, place an enquiry, negotiate a purchase order and build an application. This is followed by after-sales documentation, to incorporate the designed application into a whole system, use, operate and maintain the product. Audiences are divided between the product user, customer support and commissioning project staff. 

Some important communications along the PEC value chain: 

1. A corporate brochure or presentation describes the specialised nature of a device manufacturer’s business, the company’s technical capabilities, managerial abilities, references, position or image in the market, financial strengths, etc. This provides the much needed credentials. Its target audience comprises technocrats and generalist decision-makers in the PEC equipment or OEM and systems industry.

2. A technical brochure or catalogue provides basic information for the systems designer to select a device – mainly product code, outlined specs, competitors’ equivalent, safety points, warranty and disclaimer statements. 

3. An enquiry form, estimation sheet or price list supports the above, to provide the designer with cost implications. This assists OEM buying decisions. 

4. Once the product concept is sold, the designer is provided with an Application Note, carrying full details including specs, characteristic graphs, elevation drawings and foot-prints, to guide the design of a circuit or equipment, or an application manual for designing/developing all possible applications with the range of devices. This may also define requirements of ancillary components e.g. heat-sinks, and RC filters in an SCR application note. 

5. To sell the product itself, a quotation form may be designed, carrying appropriate techno-commercial details such as product code, quantity, delivery schedule, price, taxes, other terms and conditions.

6. Post sales, the vendor often sends the customer a Sale Note or Order Confirmation to ensure that the buyer and seller are concurrent. 

7. The product itself is accompanied by some basic information like product code or voltage and current ratings along with handling instructions and drilling templates to allow safe transit, installation and inspection. They may be leaflets provided in the packing or written on the cartons of the devices. In transit, transporters and revenue staff read these details. Assessment for tax or Duty and concessions are also done from the information here as are unpacking, storage and fitting. 

8. Warranty cards accompany the above. 

9. In lieu of pre-sales application data, a post-sales instruction manual may be provided, to guide the user of the device from unpacking to final commissioning. 

10. In the Post-Internet scenario, the above communications 1 to 6 are supported if not replaced by a variety of e-solutions, ranging from simple reference websites to e-shops that reduce interaction time, paperwork and intermediation costs. The later stages 7 to 9 are further supported by a slew of supply-chain and logistic management solutions to reduce in-transit man-hours, inventories and lead-time. ERP and EWI technologies are trying to encompass all the above. 

From this stage onwards, the variety of communications increases, along with the complexity. A larger number of PEC equipment is made from combinations of several devices, other components and materials. While the device manufacturer’s responsibility ends with meeting the inspection norms at the customer’s end, an OEM or equipment manufacturer is often accountable, directly or indirectly, to the performance of the buyer’s system or process.

An OEM’s TC team hence develops: 

1. Inspection documents and in-house or works standards as needed, to ensure the right quality of all component s and input materials. These would guide the QC, testing and production as much as purchase and accounts functions to track supplies and process payments. 

2. Equipment drawings, data-sheets, method charts and manuals for equipment assembly. 

3. Sub-contract drawings and instructional documentation as is quite common in this industry, for out-sourcing of various inductive devices, machined parts, special hardware and sub-assemblies. 

4. Wiring and interconnection drawings, with check points. 

5. Tooling drawings and instructions, for the in-house machine shop or sub-contractor. 

6. Product testing and inspection charts, drawings and manuals as applicable to the finished product, again for management functions as in 11 above. 

7. General Arrangement GA Drawings, Erection & Commissioning instruction-sheets or drawings for installation and location of the equipment at site. The OEM’s project staff, system integrator and system owner require these. 

8. Schedule of commissioning accessories & consumables – including grouting bolts, hooks, hangers, insert-plates, piano-wires for X-Y axis marking, coolants and lubricants, oil, de-ionised water or DM plant, compressed air and filters. Such materials are not manufactured by most OEMs but under their scope of responsibility. In India, the nature of Excise and Sales Tax laws make it practical for the buyer to purchase these directly. 

9. Other communications described in 1 to 9 above, but applicable to this equipment. 

10. Service manuals for the customer support staff. 

11. Operations & Maintenance manuals. 

12. A cross-reference such as index or covering document, in case of multi-assembly equipment, to facilitate inspection, pre-despatch, in transit or at site, by various agencies.

Cross-functional communication is an important point here. For example, a drive designer is thoroughly conversant with the behaviour of motors and circuitry to regulate them. But the buyers are, typically, from a diverse spread of industries – steel, aluminium rolling, fabrics processing, plastic extrusion – often they are mechanical engineers and generalist administrators. Each industry has its standard conventions, nomenclature, and visual representation styles. The tech communicator must consider this in the choice of visual symbols, diagrams, drawings, linguistic style and terminology. 

Moving towards the big picture, industrial electronics also deals with controls and instrumentation for the power system or grid. C&I applications are omnipresent here - monitoring, recording, indicating, integrating and processing information - from measuring generator bearing temperatures to switch on/off an oil pump, regulating the fuel input in a thermal power plant according to power demand, from measuring voltages and currents, detecting faults all along the transmission and distribution networks or T&D… to protecting you from a shock, to timing your toaster-oven. C&I is also the vehicle for IT integration in the power system as well as the vehicle for convergence of IT with communication or ICT. Here we have a massive variety of devices, equipment and systems - beginning with simple sensors, signal converters and controllers… to web-enabled embedded controls, distributed digital controls, SCADA, power-line communications, man-machine interfaces, IT-enabled power station automation, grid monitoring and regulation systems... 

Here too, the scope of documentation is as wide as the multitude of equipment, processes and applications. The sequence of communications is akin to that illustrated in the PEC case, but wider in reach. 

Power systems incorporate the above PLUS electrical machines – motors, alternators, dynamos and transformers; Switchgear & protective devices – protection and control relays, contactors, circuit breakers, power switches, isolators and combinations including these, like switchboards, PCCs or power control centres, MCCs or motor control centres, network protection systems, etc. Voltage ratings span from 12 V AC/DC to 400 kV in the Indian context. The line voltage is normally stepped up to save on line current and thus, the size of the conductor carrying it, limiting the current rating to mostly 2500 or 4000 Amps for every standard voltage rating. Hence again there is a vast range of documentation to assist the user in selection and use of each kind of product - standard as well as tailor-made. India has a globally competitive power equipment industry. 

All power systems have a basic function - to manage the flow of electrical energy from source to load - safely, reliably and efficiently, at the right voltage, current and frequency. All documentation here supports this objective. As the power rating increases, so do the criticality of safety and reliability. A small error or defect can damage an entire district! It is clear that the system integrator and owner (both the same in case of our State Electricity Boards) must ensure that everybody’s buck stops with them. 

An example here illustrates the complexities faced by the technical communicator at the system level: 

There are about 100 standardised types of network protection relays alone – each dedicated e.g. under-voltage, over-current … Each of these is made by a specialist manufacturer, supplied to a protection systems integrator and supplied to a public utility company or large power user. All along this chain, the product enhances, from device to system. Different applications and systems engineers need to be informed to test, calibrate, mount and adjust the relay as well as connect the right CTs, power pack and signal wiring. One mistake can send an entire State into darkness or trip a large power station. This calls for a variety of comprehensive, unambiguous and authentic application notes, system drawings, data-sheets and instruction manuals. 

Standards play a vital role. ISO, DIN, IEC, VDE and JIS besides our IBS are among the dominant standards. One can reach the websites of these bodies by a simple search. These also deal with all related areas of documentation. Beside this, organizations write their in-house Works Standards - another opening. ISO has gained importance, with many countries stipulating ISO 9000 approval for manufacturers seeking entry in their markets. ISO quality documentation in industry requires complete tracking of all raw material from its

Safety, quality and reliability engineering are other ‘hot’ documentation areas. 

The system integrator and owner’s TC team, therefore must compliment the above steps 1 to 22, with: 

1. A compendium or index of vendor-OEMs documentation, constantly updated. 

2. A record of inspections carried out on incoming equipment, rejections or deviations included.

3. As Done Sketches or drawings of erection work done esp. if deviating from vendors’ GA Drawings. 

4. Design documentation of in-house fabrications like chimneys, ducts, structural components, etc. 

5. GA Drawings for integrated multi-equipment in-house installations, like power-plant, sub-station, switchyard, utilities house, integrated process lines, etc as applicable. 

6. Civil engineering drawings of all related structures, with inspection and deviation reports, if any.

7. Architectural drawings, esp. details like illumination, ventilation, wiring, plumbing, air-conditioning, etc. 

8. Maintenance schedule and logging documentation. 

9. Relevant Standards, for reference. 

10. Library and control system for accessing, referencing and transmittal of all above documentation. 

Common TC issues

Does all this mention of drawings and data sheets write off the TW? Certainly not! On average, for every 2 drawings and data-sheets, there is one manual per product. And this manual is central to the whole document set. 

Cross-functional communication is an important point here. For example, a drive designer is thoroughly conversant with behaviour of motors and circuitry to regulate them. But the buyers are, typically, from a diverse spread of industries – steel, aluminum rolling, fabrics processing, plastic extrusion – often they are mechanical, chemical or textile engineers and generalist administrators at that. Each industry has its standard conventions, nomenclature, and visual representation styles. The TC must consider this in the choice of visual symbols, diagrams, drawings and terminology. 

As is very obvious above, all above documents and techno-commercial if not purely technical. Any candidate for a TC role must be therefore, not only technically conversant with the client or employer’s product, but also how it is used, what the user calls it, how the user applies it and what that user expects from the product. This calls for ambidexterity in technical and communication abilities. The writer, especially, must liase with the diverse target audience groups. 

A technical writer in power systems must be a perfect jack-of -all trades, with flair to glean information on materials, equipments, systems, applications – and the related skills! A keen eye for detail is critical. The smallest slip can cause a serious mishap. But curiosity never killed a good technical writer! Being a good electrical engineer inherently takes care of most of these requirements - certainly not all. 

The scope is limitless to the self-motivated communicator. 

Further reading

You may want to read a detailed posting by the author at the TC-Forum Website in the TC-Forum, December 1999 edition. To view the posting, follow the link www.tc-forum.org/topicspe/sa07comm.htm. 

(Udit Chaudhuri supports development projects and the introduction of new products, with his writing and visual presentation skills. Industrial electronics, ICT and energy systems are his special interest. Besides, he takes keen interest in issues related to technology, industrial development and environment." You can contact him at unika@softhome.net.)

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