Introduction EPCM refers to Engineering, Procurement,
Construction Management. It is a common form
An EPC project is a well-known project management of contracting arrangement within the construction
term used internationally. It refers to performing a industry. In an EPCM arrangement, the contractor is
complete project on a lump sump turnkey basis which not in fact the constructor. Rather the EPCM designs,
encompasses the engineering, procurement and procures and manages the construction process as
construction of the whole project. The FEED (front end an agent of the project Owner. While the C stands for
engineering design) forms the basis of detailed design construction, this is in the context of CM, Construction
of the complete project, which in turn generates the Management. Unlike an EPC contract, an EPCM
basic data for the procurement and civil, mechanical, contract is essentially a contract for professional
electrical and instrumentation (CME&I) works of an services, based on a schedule of rates.
EPC project. The project objective is to ensure safe, EPC and EPCM contracts are quite different in
timely, and successful completion of the EPC project terms of risks and allocations. The advantage from
within allocated budget. the Owners’ point of view of an EPC contract is that
the contractor takes full responsibility in respect of
EPC and EPCM Contracts the following:
EPC stands for Engineering, Procurement and l cost of completion if it is a lump sum contract
Construction. It is a common form of contracting (subject to limited adjustments)
arrangement within the construction industry. l the time for completion (subject to extensions
Under an EPC contract, the contractor will design of time)
the installation, procure the necessary materials
l the quality of the design and work and achievement
and construct it, either through own labour or by of performance guarantees (subject to any
subcontracting part of the work. The contractor exclusion)
carries the project risk for schedule as well as budget
The potential for multiple disputes is avoided in
in return for a fixed price, called lumpsum or LSTK
EPC. However, the major disadvantage for the Owner
depending on the agreed scope of work.
of the EPC contract, when compared to the EPCM
When scope is restricted to engineering and contract, is that the detailed design is the contractor’s
procurement only, this is referred to as an EP or prerogative. Accordingly, in an EPC contract, great
E+P contract. This is often done in situations where care needs to be taken that the Owner specifies
the construction risk is massive for the contractor or and defines the design parameters and deliverables,
when the Owner prefers to do construction himself. including consumption of utilities and emissions.
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Substation EPC Project Role of Project Design Team
In EPC contract, the Contractor is responsible for The Client’s responsibilities include identify
all design, procurement and construction services project goals, decide a project delivery system,
needed to complete a substation. These services determine whether Client needs assistance of a
may be performed solely by the contractor or sub- consultant, select a representative and determine any
contracted to others. The Client, in turn, typically has limitations on the representative’s authority, decide
a number of responsibilities that include providing upon a procurement process for EPC, determine
final substation circuit diagrams, procurement the appropriate payment methodology for EPC
specifications, design criteria, site selection, site plans contract, allocate project risk, obtain project financing,
and obtaining regulatory permits. furnish site information, identify deliverables, review
and approve design submissions of EPC, inspect
A Substation EPC project life cycle includes:
construction for compliance with contract, develop
l Pre-Qualification efficient change order process, and obtain appropriate
l Submitting the Proposal to the Client project insurance. The substation EPC project design
team’s responsibilities include deliverables according
l Negotiation with vendors, subcontractors and
to the contract between Client and the Contractor. The
Electrical engineering group develops the electrical
l Design and Procurement of major equipment drawings and the Civil engineering group develops
l Construction the civil drawings for Client’s review. The electrical
and civil drawings will be issued for construction
l Testing and Commissioning
after Client’s approval. Substation EPC project design
l Operation and transferring the substation and team also reviews and approves vendor drawings.
warranty of equipment to the Client
Project coordinator keeps track of the electrical
Successful substation EPC project delivery is and civil deliverables and construction activities.
dependent on assembling the right project team. Design criteria is very important for a substation EPC
Substation EPC project teams are formed before project because substation equipment, materials,
pursuing an EPC project and tailored to satisfy the and construction cost will be established using the
Client’s needs and specifications. Large Substation defined design criteria.
EPC project design teams may consist of: a project If design criteria changes in the middle of the
manager and a project coordinator; an engineering EPC project, engineering and construction reworking
manager, a lead electrical engineer and one to three cost can be expensive for both the Client and the
electrical engineers; a lead civil engineer and one Contractor. Quality Assurance and Quality Control
to three civil engineers; a drafting manager, one Program must be involved throughout the length
to three drafters; permitting and land acquisition; of the project to ensure that project objectives are
a purchaser; a construction manager, a contractor, met. Design manual, detailed civil and electrical
and subcontractors. engineering design for the substation EPC project
In order to facilitate the process of understanding will be provided to Client by the Contractor.
the project’s scope, prior to the start of the Design
Phase, the contractor must hold a partnering session Project Design
attended by the in-house Design-Build team as well
Substation will be designed in accordance with
as the Client’s team. The partnering session provides
applicable Client’s standards, industry standards
an overview of the design-build schedule, quality
and codes, and central, state or local requirements.
control plan, permit requirements and coordination
Packages such as MicroStation or AutoCAD are
of the work between all entities.
employed for detailing and drafting applications.
Some of the activities of a substation EPC project The project design manual addresses the specific
may not be started before other tasks or portion of parameters of the design including applicable
tasks or activities have been completed. For example, standards, codes, and interpretations of codes and
foundations for the steel structures must be in long standards that may affect the design. The project
before erecting the steel structures can start. Site design manual also addresses the scope of the project
grading and excavation must proceed before installing and any specialized or unique design techniques
the steel structure foundations. used in the development of the design documents.
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Client’s specifications provide a comprehensive sequenced based on interrelationships such that
approach to the procurement process, and pre-qualify time usage can be calculated to determine the
suppliers. Substation equipment and materials bid earliest date work can be accomplished and the
documents include bid forms, general requirements, latest date work needs to be completed. The critical
design condition, major equipments, steel structures, path is the longest activity path from the start to
equipment and materials, control building, and relay finish of the project.
panels. Substation construction includes construction
An activity, which is not on the critical path, will
management, site work including grading and erosion
have float. Float is the amount of time an activity can
control, installation of fence, major equipments,
be delayed without it becoming a critical path activity.
foundations, grounding, conduit, raceway, control
Any activity on the critical path that experiences a
building, relay panels, and steel structures erection
delay will consequently delay the project milestone
and equipment testing.
or completion date or require corrective action.
Avoidance of any occupational related deaths or
CPM Schedule forces the scheduler, construction
injuries must be accorded high priority. Subcontractors
supervisor, and the project manager to think through
must be made aware from the onset that safety will
the entire project in detail to avoid inefficient and
play a significant role in the success of the project.
poor sequencing of the project, and helps the project
manager to define and plan the work in detail from start
Critical Path Method (CPM) Schedule to finish. Sequences can be changed to overcome or
CPM Schedule is a network scheduling technique reduce any impact. CPM Schedules support efficient
where large elements of a project are subdivided communication between field and office forces. It
based on a hierarchical system (work breakdown can assist in a smooth transition for execution of the
structure) into single work steps (activities) and plan if management staff changes are made during
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the project. It makes job coordination easier among and construction cost will be established using the
material suppliers, contractors, subcontractors, client, defined design criteria. Project design conditions
and designers. are information that are applicable to all structure,
equipment and material designs. Seismic zone,
Client’s Responsibility in Substation EPC altitude, annual precipitation, design loading district,
wind velocity, and ice accumulation information is
Project useful in substation design and are to be provided
The Client’s primary function is to create the project to the equipment and material suppliers for use in
and pay for it. The Client also has the corresponding their designs.
duty to manage how the project will be developed Weather data influences the design for the area of
and selecting a project delivery system. A 15-point the substation. Temperature, isokeraunic level, wind
checklist for Client’s responsibilities, as follows: speeds, and ice play a big role designing substations.
l Identify project goals. Substation electrical system information is required
to design optimally. The electrical system ratings
l Decide upon a project delivery system, which will
include nominal system voltage, maximum system
give the Client best chance to achieve project
voltage, station BIL, available fault current, continuous
current, short circuit withstand current, and system
l Determine whether Client needs assistance of a frequency. The substation structure design load cases
consultant. are necessary to know before the substation structure
l Select a representative and determine any calculations start. The substation structure design
limitations on the representative’s authority. load cases including weight of equipment, structure,
light, medium, and heavy wind, short circuit and ice
l Decide upon a procurement process for EPC.
loadings determine the size of the structures that will
l Determine the appropriate payment methodology be required for the substation.
(e.g., cost plus, lump sum) for EPC contract.
The rigid bus design helps to accommodate
l Identify and allocate project risk. alternate feeds through adjacent breakers in the
l Obtain project financing. event of required maintenance or line fault. Electrical
clearances for the bus must be maintained to protect
l Furnish site information. people and equipment moving underneath the
l Secure agreements with adjacent property substation. Phase-to-ground and phase-to-phase
Clients. clearances should be coordinated to ensure that
possible flashovers occur from phase-to-ground
l Identify Client-furnished deliverables (e.g., permits,
rather than from phase-to phase.
furnishings) and develop process for timely
obtaining such deliverables. Major substation electrical equipment is custom
designed, has longer delivery time, and is expensive.
l Review design submissions of EPC.
Substation grounding protects personnel from touch
l Inspect construction for compliance with and step potential. The touch and step voltages
contract. produced in a fault condition have to be at safe
l Develop efficient change order process. values. The substation grounding system consists
of driven ground rods, buried interconnecting
l Obtain appropriate project insurance.
grounding cables or grid, equipment ground mats,
The Client of an EPC project typically is responsible connecting cables from grid to metallic parts of
for obtaining many permits and Approvals. It is structures and equipment, connections to grounded
important for the Client to have a clear understanding system neutrals, and the ground surface insulating
of its permit obligations and the Client must have a covering material.
plan in place for obtaining such permits and approvals.
Substation electrical equipment can be subject
Client’s inability to obtain the permits and approvals to abnormal conditions as a result of direct lightning
can result in major delays in the project. strokes. Shielding design analyzes and recommends
procedures for direct stroke protection for the
Substation Design Criteria substations and substation equipment.
Design criteria is very important for a substation Raceway in the form of conduit, tray, and trench,
EPC project because substation equipment, materials, are used in the substations to provide protection
36 November 2009
and segregation of cables. Raceway sizing is an
important parameter in substation design notably for
a large installation. Protective relays detect defective
lines or apparatus and initiate the operation of
appropriate circuit interrupting devices in order to
isolate the defective lines or equipment. Relays also
detect abnormal or undesirable operating conditions,
other than those caused by defective equipment and
either operate an alarm or initiate operation of circuit
The high-speed operation of these relays minimizes
damage to the electrical system and helps to maintain
service continuity to the rest of the electrical system.
The type of relay or relay system selected by the to reduce time scale and to obtain better EPC projects.
substation engineer for an application is of primary These project challenges lead to cost overrun and
importance. The electric system inputs that will be schedule delay.
available to the relay and the speed with which the
relay must operate to maintain electric system stability Studies reveal that major factors contributing
must be known. to schedule delay and cost overrun are mostly
related to material and equipment such as material
Site work design of substation yard should be such shortage, procurement delay or late delivery on site.
as to provide an easily accessible, dry, maintenance Besides, delay in placing purchase order, design
free area for the installation and operation of electrical changes, lack of EPC contractor’s experience, late
substation equipment and structures. A variety of approvals, vendor information coming in late and
structure types are used in electrical substations and further most due to the lack of coordination between
these structures have a wide range of ground line Client, contractor and suppliers regarding exchange
reactions. Typical substation foundation types can be of information are other factors contributing cost
slabs on grade, spread footings, drilled shafts and overrun and schedule delay.
piling with and without pile caps. Foundations should
Poor planning and controlling, lack of top
be designed such that they do not exceed deflection
management commitment, unrealistic project
criteria of the structure.
scheduling and poor coordination and communication
Substation structures are designed to reliably are some more project management practices
support electrical equipment and maintain clearances. observed. However, subcontractor management and
Since excessive structure movement can cause control mechanism, lesson learnt practice, involvement
electrical equipment to experience mechanical of construction and operational personnel during
damage, operational difficulties and electrical faults, conceptual phase are success project management
structures are designed to meet strength and deflection practice found.
criteria under a variety of loading conditions.
Furthermore, interface management and
The control building provides a weatherproof and control, integrated team management, real time
environmentally controlled enclosure for substation reaction, dispute management, risk management,
equipment including relays, meters, controls, stakeholder management, continuous and dynamic
batteries and communications equipment. Additional detail planning and monitoring during execution
space should be provided for workshops, equipment and being proactive to
testing and repair and storage. Control building layout issues, carrots and sticks
includes controls, relay panels, DC equipment, AC approach (incentive
equipment, cable tray and lighting. criteria), clear roles and
responsibilities, etc are
Problems and Practices in EPC Project also the big concerns
in terms of project
Management management practice
EPC projects face many challenges to stay in the regarding controlling
M P Jayprakash
competitive world despite the efforts made towards cost overrun and
compressing activities by phase overlapping, in order schedule delay.
38 November 2009