15.2.0 General Requirements
15.2.1 The Contractor shall provide Control & Instrumentation systems PLC based control systems for station auxiliaries equipment mounted/local instruments and transmitters including sensing elements as required, Local instrument enclosures/racks, Local gauge boards/racks, Process Connection and Piping, Sample lines, Electric Power Supply System, Actuators for valves, Instrumentation Cables etc. as identified in the specification.
15.2.2 The Contractor shall provide all material, equipment and services so as to make a totally integrated Instrumentation and Control System together with all accessories, auxiliaries and associated equipments ensuring operability, maintainability and reliability. The work shall be consistent with modern power plant practices and shall be in compliance with all applicable codes, standards, guides, statutory regulations and safety requirements in force.
15.2.3 The Contractor shall include in his proposal all instruments and devices, which are needed for the completeness of the system. Same shall be subject to approval of the purchaser during detailed engineering. All instruments and control equipments like primary and secondary instruments etc. shall meet the functional requirements . In addition, all electrical instrument solenoid valves which are located in the field/hazardous locations shall be provided with explosion proof enclosure suitable for hazardous areas described in National Electric Code (USA), Article 500, Class-I, Division-I. All field wiring should be through conduits. All fittings, cable glands etc .shall be strictly as per NEC recommendation article, 500 to 503.,
15.2.4 All instrumentation and control equipment, instruments, instrumentation support steel work for gauge board, cabinet, local remote instruments and pipe work shall be suitable for guaranteed performance at the ambient, humid, dusty and corrosive conditions prevailing at site and specified elsewhere. Environmental test for all electronic items shall be carried out as per IS: 2106 or equivalent standard acceptable to the owner. All indoor equipment shall be suitable for continuous safe operation at ambient of 50 degree centigrade and also during periods of air conditioning failure without any loss of function, or departure from the specification requirements covered under this specification. The panels/desk/cubicles located in air conditioned area and indoor shall comply with the requirement of protection class IP-42 and panels located in outdoor areas shall be IP-65 as per IS: 2147. All outdoor instruments and control devices shall be suitable for ambient of 80 Degree centigrade and humidity of 95%. Degree of protection for outdoor equipment shall be minimum IP-65 as per IS: 2147.
15.2.5 The equipment offered shall be of proven make and design, ensuring reliability, safety, efficiency and long continuous trouble-free service with high economy and low maintenance costs. The C&I system offered shall meet the operation requirements in all regimes, control philosophy, design concepts, sizing and design criteria as indicated in various sections of this specification. The equipments/devices offered shall be suitable for satisfactory operation at ambient temperature specified with dusty, humid and corrosive conditions faced in thatl area and their design principles shall take into account but not be limited to the following :-
a) Interchangeability and expandability
b) Malfunction identification
c) Maintainability
d) Shock and vibration proofing
e) Short circuit proofing
f) Over-voltage protection
g) Easy access to all components
h) Highest class workmanship general finish
i) Adequate space availability for connecting external cables.
j) Noise immunity including immunity against radio frequency interference and electromagnetic interference to be provided with opto/galvanic isolation.
k) Avoidance of overheating of electronic components
l) Fail safe operation: It shall be ensured by the bidder that failure of any sensor, transmitter, controller, final control element, power or control supply shall not cause a hazardous condition. Further, such a failure should provide audio and visual alarms.
m) Surge protection for electronic components as per IEEE-472.
n) Selection of high quality equipments/material.
15.2.6 All equipment/systems covered under the specification shall be subject to inspection and tests as per the relevant standards including any additional tests considered necessary by the purchaser during manufacture, erection and on completion of the work. The approval of the purchaser on passing of such inspection of test will not, however, prejudice the right of purchaser to reject the equipment if it does not comply with specification requirements when erected or does not give satisfactory performance in service.
15.2.7 The responsibility for safe, efficient and reliable operation of the equipment/system supplied shall rest with the bidder. Approval of the drawings by purchaser/consultant shall not in any way relieve the bidder of his obligation/responsibility in this respect.
15.2.8 Contractor shall include in his bid a detailed Bill of Material (BOM) for each of the systems.
15.2.9 All panels, desks, cabinets shall be provided with a continuous bare copper ground bus. The ground bus shall be bolted to the panel structure on bottom on both sides. The contractor shall submit with the offer recommended grounding scheme required for control system. The exact grounding scheme shall be finalized during detailed engineering.
15.2.10 The control system and various equipment shall conform to the requirements specified in the section -6 of BTG package, which are not specifically covered herein
