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1. SCOPE
As a part of purchaser’s Material Purchase Specification (MPS), this specification is to provide the technical requirements for the electrical equipment, components and devices which are required to be furnished by the mechanical supplier, as a part (or parts) of the mechanical equipment or system, to ensure the satisfactory, safe and optimized operation.
2. ASSIGNMENT OF RESPONSIBILITY
2.1 Equipment Supply
Purchaser’s MPS including this specification do not endeavor to enumerate all the electrical, instrumentation and control items required for the proper function of mechanical equipment / system. The supplier shall supply all those items under his responsibility whether or not it is specified in the MPS. All the items to be supplied shall be specified in the supplier’s proposal item by item as a comprehensible manner.
2.2 Drawing and document supply
The supplier shall be responsible for providing the drawings and documents in accordance to the requirement indicated somewhere in MPS. It shall be understood that any defect in documentation procedure such as missing or delay will force the supplier to take the contractual obligation as the case of equipment supply.
2.3 Compliance with applicable Standards and regulation
It is the supplier’s responsibility that all the supplies under the contract shall conform to the applicable standards and regulations specified somewhere in MPS. Any additional cost arisen from non-compliance will not be accepted by the purchaser in any case.
2.4 Authoritative interpretation
If there are any different opinions or arguments between the purchaser and the supplier in interpretation of this specification, the supplier must follow the purchaser’s interpretation.
2.5 Y2K
All supplied equipment and software will be Y2K compliance.
3. APPLICABLE STANDARDS
KS Korean Standard (5)
JIS Japanese Industrial Standard
JEM Japanese Electrical Manufacturing standards (4)
ANSI American National Standard Institute
IEEE Institute of Electrical and Electronic Engineers
NEMA National Electrical Manufacturers Association
NEC National Electrical Code
IEC International Electrotechnical Committee (1)
BS British Standard (3)
DIN Deutche Industri Normen (2)
Note : Numbers in the bracket (right hand) indicates the priority of application.
4. DESIGN REQUIREMENTS
4.1 Voltage level and frequency
Note : The following voltage level indicates the standard voltages applied to this project. It shall not be interpreted that all voltage levels may be available for the supplier’s system.
a. Voltage level
1) Incoming power 33kV AC, 3 ph, 3 wires
2) Symmetrical fault level for 1 sec. Less than 25KA at 6.3kV
3) Medium voltage distribution 6.3kV AC, 3 ph, 3 wires
4) Low voltage distribution 415V AC, 3 ph, 4 wires (3ph+N+E)
5) Medium voltage motors 6.3kV AC, 3 ph
6) Low voltage motors 415V AC, 3 ph
7) Lighting and general circuit 240V AC, 1 ph
8) Switch socket outlets 240V AC, 1 ph
9) Control circuit for HV & MV switchgear 110V DC
10) Control circuit for LV switchgear & MCC 220V AC, 1 ph
11) Digital input & outputs 110V AC (minimum)
12) Conventional switches 110V AC (minimum)
13) Analogue inputs and outputs 4- 20mA DC
b. Frequency 50 Hz
4.2 General environmental condition
a. Climate Tropical Temperate Cold
b. Temperature Maximum 40 deg C
Minimum - 5 deg C
Note : The design temperature of the equipment located in the production area shall be +55 deg C.
c. Altitude Less than 1000 meters above sea level
d. Humidity Maximum relative humidity 95 %
4.3 Tropicalization
To protect against the tropical conditions at the plant site, the electrical equipment shall be treated as follows.
a. All switchgear and motor control equipment shall be equipped with space heaters.
b. All electrical equipment openings shall have a measure of rodent proof.
4.4 Standardization requirement
In order to limit the required stock of spare parts, the supplier shall use, wherever feasible, the same make, standard size and capacities of equipment/ device/instrument/ component according to the purchaser’s information, throughout his scope of supply.
a. Electrical Equipment
1) Maker / Type
The supplier shall provide the list of concerned items for the purchaser’s approval prior to proceed the procurement or manufacturing.
2) Motor
The rated output valve (rated kW) shall be subject to IEC 72, sec. 9 “ Preferred rated output values”. It is intended to minimize the number of sizes of motors throughout the plant.
3) The color of signal lamp
- Power on White
- Motor run Red
- Motor stop Green
- Fault Amber
4) The color of cable
The supplier shall confirm the color of cable prior to proceed the procurement or manufacturing.
b. Field devices / instrument (see 4.7.4 of this specification)
c. The color of control cables, pushbuttons signal lamps, control switches and the like shall be standardized throughout the plant according to the function of the element.
4.5 Units and language
All dimension and weight shall be in metric system.
All drawings and documents shall be in English.
4.6 Voltage drop
The total allowable voltage drop from the Sub control system to any load shall not exceed 5% for power circuit at normal operation. During the starting of the motors, the allowable voltage drop shall not exceed 10%.
4.7 Technical requirements
4.7.1 Sub control system (SCS)
Electrical control systems supplied as a complete system for certain equipment or machinery are considered as “ Sub- Control system “.
The purchaser will supply one electrical power for the SCS from a low voltage distribution, 415V, 3ph+N+E or H+N+E, as requested by the supplier. The supplier shall provide the required power for his motors/consumers from SCS and shall include the protection of feed cable. The provision of internal control voltage and the electrical protection of consumers are the scope of supplier.
If any other type of power source is required, the supplier shall provide all relevant devices to fulfil the power source requirement.
4.7.2 Motor control centers (MCC), in case the supplier provides.
The motor control centers shall comprise of all equipment for a safe remote control and consist of process power / motor feeders. The permissive signal for local mode operation shall be obtained from plant automation system.
Every motor feeder throughout the whole plant must be equipped with a thermal overload protection as a minimum requirement.
The motor control centers shall be of front panels, bottom cable entry, sheet steel enclosed, floor mounting, free standing. The MCCs shall have series of panels of uniform height placed side by side.
Each MCC shall be divided into suitable number of shipping sections with facilities for assembling them at site.
Each vertical section shall be provided with main horizontal busbars and shall be divided by horizontal sheet steel partitions into independent cells/compartments.
The compartment door shall be so interlocked that it shall not be possible to open the door with the Isolating switch / MCCB in closed position. However, it shall be possible to intentionally defeat this interlock for inspection and testing.
Facility shall be provided to padlock the Isolating switch / MCCB operating handles in ON or OFF positions.
The draw out chassis should have service / isolate and test positions with position indicator. In service position, both power and control supplies shall be available. In test position, only control supply shall be available. To isolate control power, the plug for control power shall be pulled.
The busbars in the MCCs shall be air insulated and made of copper. The power and control wiring in the MCC's shall be carried out with stranded PVC copper conductor cable. The power and control wiring shall be with color identification.
Feeder components of each feeder shall be selected as per the type of connected loads.
Feeders more than 110KW shall be provided with CT operated ammeters.
All control components as may be required for interlocking with plant automation system may be included in the MCC.
The starter (direct on line) unit of up to 75KW is draw out type.
Rating and specification
- Rated operating voltage AC 415V
- Control voltage AC 240V
- Rated frequency 50Hz
- Bus bar Copper, air insulated (bare)
- Cubicle Indoor use, self-standing
- Degree of protection IP21
- Power cable for incoming Bottom part of cubicle
- Power cable for load Right side of each starter unit
- Control cable Right side of each starter unit
Starter unit
Each starter unit is provided ( in case of non-reverse drive) for motor.
- Molded case circuit breaker (MCCB) with an auxiliary contactor
- Magnetic contactor (MC)
- Thermal overload relay (3-element)
- Auxiliary relay
- Indication lamp
- Current transformer (if required)
- Ammeter (if required)
- Mechanical interlocking between the operation handle of MCCB and unit door.
- Spare unit
As a whole, MCC will have minimum 10% of spare units
- Control power supply
AC 220V, single phase, 50Hz control power will be provided in each group of MCC
4.7.3 Drives
The drives supplied by the mechanical supplier shall comply with the following general requirements.
a. Motors of IEC rating 250 kW and larger shall be 6.3 kV high voltage motors and those smaller than 250 kW shall be 415V low voltage motor.
b. All motors shall be totally enclosed fan cooled (TEFC) of the protection type IP54 or better and shall be furnished with insulation class F / temperature rise class B.
c. All motors are to be equipped with an over-sized terminal box to provide ample space for convenient connection / termination. In case of the motors to be connected with the purchaser-supplied cable, the supplier shall be responsible for providing the properly sized terminal box as per the cable size informed by the purchaser.
d. The individual drive's specific starting and operating requirements shall be carefully considered. To minimize maintenance, squirrel cage motors shall be applied where possible.
e. Variable speed drives
1) Thyristor and transistor converter
The thyristor and transistor converters are enclosed in metal cabinets of free standing design except for small size VVVF controllers, and protection class of IP20. During the normal operation, the speed setting is referenced remotely by 4-20 mA DC signal, and the output signals are transferred to the DCS system by 4-20 mA DC.
2) VVVF control system
The operation of the frequency converter is based on pulse width modulation (PWM). The inverter has either giant transistors or gate turn-off transistors depending on the power requirement. The control system adopts a DDC (direct digital control) system.
The apparatuses for the following are provided on the panel front:
- Metering of voltage, current and frequency
- Frequency setting
- Fault indication
- Operation indication
- Local / remote switching
f. Motor data
The supplier shall be responsible for providing the motor data sheet as per the purchaser’s format enclosed in this specification.
4.7.4 Field control devices
a. General requirements
1) Operating elements, field devices and instrument items which are included as part of mechanical equipment have to be clearly defined. This definition shall include specification and function of equipment, quantity and make.
2) The control devices (maker/type) are subject to approval by the purchaser.
b. Basic design criteria
1) Ingress protection
Dust proof / Water proof : IP54
Where installed in the outdoor : IP65
2) Explosion proof where required.
3) Housing to be of corrosion resistant.
4) Resistant against vibration
5) Suitable for ambient temperature of – 20 deg C to + 70 deg C
6) Current rating of contact : 10 A at 220V dc
7) Electronics
Short circuit proof
Protected from inductive voltage spikes
Maximum inverse voltage and over-voltage protection
8) Analog : 4- 20mA Galvanically isolated (against earth and power supply)
9) Connections : Lug type connections or 1.5 m long extension cable
c. Requirement on the individual control devices
1) Motion detectors
Shall be standardized proximity head type limit switches where possible to the final driven element of machine. Motion detectors shall be installed with belt conveyors, V-belt driven equipment, rotary feeders, bucket elevators, screw conveyors, weigh feeders, etc where required.
2) Limit switches
Shall be subject to approval by purchaser for standardization. Application of limit switches will be to chute gates, belt take-up, tripper positioning, valve position, chute position, brake position and similar application where required.
3) Level detectors
Types of level detectors vary for individual applications. All bins, silos and other means of storage shall have level devices according to the process requirement. Where required for process information, continuous analog level measuring devices shall be additionally foreseen.
4) Rope switches
Emergency rope switches shall be installed along every belt conveyor walkway and will extend over the entire length of the belt conveyor. The rope will consist of a flexible (approx. 6mm) steel cable with plastic cable sheath and connect at either end to a pull cord switch. Emergency rope length shall not exceed 30m. The supplier shall provide the complete system including mounting brackets, rope, rope guides and rope switches.
5) Belt drift switches
Belt drift switches shall as a minimum be installed at each end of the belt conveyor and if necessary at intermediate locations. The supplier shall provide the complete system including the mounting brackets.
6) Pressure, Diff. pressure, Flow and Temperature switches/transducers for machine protection shall be supplied and installed to suit the individual application. Locally mounted, continuous monitoring devices with an isolated output 4- 20mA 2- wire technique, external load up to 600 ohm and with local indication are required. For applications which require one set point only, switches with liquid filled or pressure operated contact systems can be applied. Wherever required, by- pass, calibration or isolation valves shall be provided so that it is possible to remove or maintain the equipment without shutdown of the machine. Switches are to be adjustable over full range, calibration scale visible with the case closed.
7) Temperature detectors
Where specified or necessary for protection and monitoring of large bearings, gear boxes, high voltage motor windings, etc., the supplier shall provide and install resistance temperature detector type PT100 including junction boxes.
8) Vibration detectors
Big fans and other critical items shall be provided with vibration sensors with analog output. The scope of supply shall include the sensors and the locally mounted transmitter (with output signal 4- 20mA, galvanically isolated), but the transmitter shall not be mounted on the vibrating body.
9) Load cells
The supplier shall provide the load cells, the field mounted amplifier (isolated output 4-20mA), brackets and expansion assemblies for bins, belt scale, impact flow meter, weigh feeder, weigh bridge and other vessels. The supplier shall provide flexible copper straps to bridge over each load cell to protect them from stray welding current.
10) Control valves and actuators
Actuators and valves shall be standardized and valves shall be equipped with integrated position indicators. Actuator shall be preferably of 3 phase squirrel cage type. The feed back element shall be 4-20mA, galvanically isolated. The external limit and torque switches shall generally be included for the actuators.
4.7.5 Cable and cable installation
a. Cable
1) All cables shall be dimensioned according to the load of the connected equipment. The current carrying capacity of the cables shall be in full compliance with standards and in consideration of derating factors for ambient temperature, laying method and cooling conditions.
2) The voltage drop, even under heavy start conditions shall not exceed 10% of the nominal voltage at the terminals of the motor.
3) The color of cables for standardization throughout the plant to distinguish between the voltage levels/function of the cable shall be given by purchaser.
4) Low voltage power cables shall be unarmored XLPE insulation and shall have minimum cross section 3.5 sqmm.
5) Control cables shall be PVC insulated and shall have minimum cross section 1.5 sqmm.
6) Generally low voltage motor cables shall have four(4) cores and the forth wire shall be used for the earthing purpose.
7) Neutral and grounding wires shall not be used for any other purpose.
8) Individual wires shall be coded as per the standard requirement.
9) Extra low voltage cables shall be capable of carrying analog and digital signals in multi-conductor cable. The control cables shall be overall shielded. Instrument cables shall be twisted pairs, individual pair shield and overall shielded. Individual wires shall be coded as per the standard requirement.
10) Special cables, i.e. trailing cables for mobile equipment shall be provided with shielded wires for telephone connection.
b. Cable installation
1) All cables and wires shall be identified by the cable marker and wire marker, respectively.
2) Cable trays shall be vertically mounted throughout the plant, unless other is motivated and agreed upon.
3) Extra low voltage cables (instrumentation, process control, communication, signals) shall be installed on a separate cable tray or conduits where by a minimum distance to power cables of 300 mm will be maintained.
4) The vertical distance between cable ladders shall be normally 300 mm. In case of using one tray for power and control cable, cable barriers shall be installed on the trays.
5) Cables on vertical ladders shall be fixed by fire resistant fasteners.
6) Closed circuit system with flexible tube, couplings and bends shall applied. Conduit in concrete floor or foundation may be PVC pipies.
4.7.6 Lighting
a. Mobile equipment such as stacker, reclaimer, ship unloader, etc., shall be provided with its own lighting system fed from the machine distribution system.
b. Type of lighting fixture and illumination level shall be subject to the approval of the purchaser as per the requirement of this project.
c. All concerned installation material shall be included in the supplier’s scope.
4.7.7 Communication
The purchaser will supply the plant communication system such as telephone system and public address system. Where applicable, the supplier shall provide the provision for extending the connections, such as cabling and terminal box, etc.
4.7.8 Earthing
The supplier shall carry out the earthing of all electrical equipment in accordance to the standard requirements. The earthing system will comprise panel body/equipment, control and instrumentation, transformer neutral, lightning, etc., as applicable. The type of system earthing shall be TN-S according to IEC 364.
4.7.9 Name plates / Labels
All electrical equipment, feeders, etc., shall be clearly labeled. Name plate / labels shall be suitably sized, white with black engraving. Text shall include name of equipment and corresponding equipment code as per the approved drawings. Material of name plates/labels shall be selected considering the environmental condition of the installed location, either non-corrosive metal or plastic, fixing by screws or riveted.
5. TEST
The supplier shall carry out the test of the whole package including the concerned electrical equipment. The test procedure shall include all required electrical test, control function test, etc. Test report shall be provided.
6. DOCUMENTATION REQUIREMENTS
The following electrical drawings and documents shall be provided for the purchaser’s approval or for information.
All drawing and documents shall be prepared in accordance with IEC standard, including symbol, format and numbering system.
All documents will be in the English language.
a. Equipment specification
b. Electrical power distribution diagram including the required power (total power consumption)
c. Motor/Consumer list according to the format enclosed herein.
d. Motor release sheet according to the format enclosed herein.
e. Outline drawing showing dimensions, weight, heat dissipation, cable entry, terminal block location, arrangement of panel inside, etc.
f. Equipment erection drawing showing the equipment location, cable laying plan (cable tray and conduit layout), installation detail, etc. It shall be used for assembly or erection of supplied equipment at plant site.
g. Cable schedule showing destination of both end of cable, cable type & size, etc.
h. External wire termination diagram
i. Instrument / control device list
j. Instrument One Line Diagram showing functionally each control loop and the components used for process control. Each loop will be described concerning temperature and pressure ranges, estimated operating points, and alarm settings.
k. Electrical device flow diagram showing schematically field instruments, analog devices and digital devices.
l. Control schematic diagram
m. Control logic diagram
n. Catalog or leaflet of all component
o. Instrument data sheet
p. Logic description
q. Vendor instruction manuals
r. Instrument hook-up drawing
s. Terminal block arrangement drawings showing the location of field termination terminal blocks within the panels and wire numbers for field-mounted devices.
6.1 Required quantity of drawings and documents
SUPPLIER shall provide the number of copies for drawings and documents for electrical part as described in the general specification “list of document and drawings to be submitted”.
7. SPARE PARTS AND SPECIAL TOOL
7.1 Supply of spare parts
7.1.1 Spare part for two year operation
The supplier shall provide a complete itemized spare parts list with specification and drawings. The quantity of recommended spare parts shall be sufficient to maintain commercial operation of the plant for two (2) years.
7.1.2 Spare part for test and commissioning
The supplier shall provide the spare parts for test and commissioning at plant site.
7.2 Supply of special tools
The supplier shall provide the special tools for the operation and maintenance of the proposed equipment in his scope of supply. The list and relevant drawings shall be provided for the purchaser’s information.
l Enclosed : Attach-1 ; Motor / Consumer list
Attach-2 ; Motor release sheet
8.
Division of Responsibility
1) Electrical & Instrumentation Equipment
Item. No. | Description | Q’ty set | Scope of supply | Division of responsibility | Delivery | |||||
Buy | Sup. | B.D | D.D | E.D | M.P | Design | Supply | |||
1) Electrical equipment | ||||||||||
| 6300V SWGR for main drive motor | 1 | ○ | B | B | B | B | |||
400V motor control center | 1 | ○ | B | B | B | B | ||||
| 6300V main drive motor (3500KW) | 1 | ○ | B | B | B | B | |||
Motor for oil unit | 1 | ○ | S | S | S | S | ||||
415V isolating switch | 1 | ○ | B | B | B | B | ||||
Lighting & socket system | 1 | ○ | B | B | B | B | ||||
Grounding system | 1 | ○ | B | B | B | B | ||||
Air conditioner | 1 | ○ | B | B | B | B | ||||
Fire alarm system | 1 | ○ | B | B | B | B | ||||
| Cable between HJ supplied panel and consumers | 1 | ○ | B | B | B | B | |||
2) Instrumentation equipment | ||||||||||
| Control system including programmable controller | 1 | ○ | B | B | B | B | |||
| Local Control Panels (if required) | 1 | ○ | S | S | S | S | |||
| Sensors, Limit switches etc for control, interlock, alarm of the equipment / system supplied by vendor | 1 | ○ | S | S | S | S | |||
| Special cable for Equipment / System | 1 | ○ | S | S | S | S | |||
| Cable on pre-wire including Terminal Box. | 1 | ○ | S | S | S | S | |||
| Wiring works of electrical and instrument (except pre-wire) | 1 | ○ | B | B | B | B |
Note : 1. In any case Control Logic & Function Control Loop Design to be provided by Vendor for proper and safe operation, control, interlock and alarms of the supplied equipment / system.
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