Wednesday, March 18, 2015

GROUNDING SYSTEM

Grounding System


Ø  Ground rods 2.4 meter minimum length.
Ø  Cathode protection material is used galvanized steel.
Ø  Individual Ground rod maximum resistance should be 2.5 Ohm.
Ø  For copper or copper jacketed steel rods is a minimum of 16 mm2 in diameter or 19 mm2 in diameters.
Ø  Earth Tester is used for measuring of earthling system.
Ø  Underground wire for grounding to wire connections shall be cadweld or thermoweld. Compression connector shall not be used.
Ø  Shields wires shall be grounded only at the one point for the signal cables.
Ø  Shields and armor of power cables shall be grounded at both ends.
Ø  If used for connections of equipment to ground rods or ground grid be minimum 25 mm2 (# 4 AWG).
Ø  Metallic cable trays shall be bonded at both end points and a minimum of every 25 Meter to the local ground grid.
Ø  If buried / used for grids or interconnections of ground rods to be minimum 70 mm2 (2/0AWG).
Ø  Be copper or copper jacketed steel or galvanized steel or copper jacketed steel shall meet the requirements of UL 476 (Underwriters Laboratories).
Ø  Power Applications:     Metal cable trays must be grounded and eclectically continuous systems as per NEC article 318.

Non-Power Applications: 

                      Cable tray systems containing conductors outside the scope of NEC Article 250 (such as                                 communications, data, signal cables, etc.


Introduction:

It is the branch of engineering which deals with the measurement, monitoring, display etc. of the several of energy exchanges which take place during process operations. "In short Instrumentation is the study of Instrument."

Instrument:

Instrument is a device which is used to measure, monitor, display etc. of a process variable.

Some Saudi Aramco Standards (SAES):

1-             SAES – J-001 (Instrument Index)
2-             SAES – J-002 (Regulated Vendor List for Instrument/Technically Acceptable Instrument)
3-             SAES – J-003 (Basic Design Criteria)
4-             SAES – J-004 (Instrument Symbol and Identification)
5-             SAES – J-005 (Drawing and Forms)
6-             SAES – J-100 (Flow Measurement)
7-             SAES – J-200 (Pressure Measurement)
8-             SAES – J-300 (Level Measurement)
9-             SAES – J-400 (Temperature Measurement)
10-          SAES – J-502 (Analyzer Shelter)
11-          SAES – J-505 (Combustible Gas and Hydrogen Sulfide in Air Detection System).
12-          SAES – J-600 (Pressure Relief Valve)
13-          SEAS – J-601 (Emergency Shutdown and Isolation Systems)
14-          SAES – J-700 (Control Valve)
15-          SAES – J-801 (Control Building)
16-          SAES – J-901 (Instrument Air Supply System)
17-          SAES – J-902 (Electrical System for Instrumentation) – Cable tray Noise Susceptibility Levels (NSL)
18-          SAES – J-903 (Intrinsically Safe System)
19-          SAES – B-006 (Fire Proofing of Cable for Fire Hazardous Area)
20-          SAES – B-068 (Electrical Area Classification)
21-          SAES – P-104 (Wiring Methods and Materials)
22-          SAES – P-111 (Grounding)
23-          SAES – P-103 (UPS and DC System)
24-          SAES – T-634 (Telecommunications - Cable Testing and Acceptance)
25-          SAES – T-796 (Communications Facility Grounding Systems)
26-          SAES – T-911 (Telecommunication Conduit System Design)


Various NEC article numbers:

250          Grounding and Bonding
300          Wiring Methods & Materials
320          Armored Cable
344          Rigid Metal Conduits
352          Rigid Nonmetallic Conduits
354          Nonmetallic Underground Conduits
358          High Density Polyethylene Conduits
360          Flexible Metallic Tubing
362          Electrical Nonmetallic Tubing (ENT)
366          Power and Tray Cable
392          Cable Tray
500/505    Hazardous Location
504          Intrinsically Safe System
700          Emergency System
727          Instrument Cable Tray
760          Fire Alarm System




Some Abbreviations:

QCP                 Quality Control Plan
ITP                   Inspection Test Plan
TQ                    Technical Query
SAEP               Saudi Aramco Engineering Procedure
SAES               Saudi Aramco Engineering Standard
SAIC                 Saudi Aramco Inspection Checklist
SATIP               Saudi Aramco Typical Inspection Plan
SATR                Saudi Aramco Test Report
SASD               Saudi Aramco Standard Drawing
SAIP                 Saudi Aramco Inspection Personal
SAMSS            Saudi Aramco Materials System Specification
SASO               Saudi Arabian Standards Organization
AWC                 Armor Wire Cable
NEC                 National Electrical Code
NACE               National American Corrosion Engineers
SCADA             Supervisory Control and Data Equation
ANSI                 American National Standards Institute
ASTM               American Society for Testing and Materials
ASME               American Society of Mechanical Engineers
BS                    British Standards
IEEE                 Institute of Electrical and Electronic Engineers
ICEA                 Insulated Cable Engineers Associations
IEC                   International Electrotechnical Commission
NEMA               National Electrical Manufactures Associations
NFPA               National Fire Protection Association
ATEX                Atmospheres Explosibles
FM                   Factory Mutual
IP                     Ingress Protection
UL                    Underwriters Laboratories
ITC                   Instrument Tray Cable
PLTC                Power Limited Tray Cable
PVC                 Polyvinyl Chloride
XLPE                Cross Linked Polyethylene
XLPO               Cross Linked Polyolefin
HDP                 High Density Polyethylene
RTD                  Resistance Temperature Detector
SWA                 Still Wire Armored
MICC                Mineral Insulation Copper Conductor
PILC                 Paper Insulation Copper Conductor
FOC                 Fiber Optical Cable
OTDR               Optical Time Domain Reflectometer
RTA                  Request for Technical Approval

MTC                 Material Test Certificate

Color Code:

AC Supply:                   Phase               Black
                                    Neutral              White
                                    Ground             Green or Green with yellow tracer

DC Supply:                   Positive                        Red
                                    Negative           Black

Signal Pair:                  Positive                        Black
                                    Negative           White

Signal Tried:                Positive            Black
                                    Negative           White
                                    Third Wire         Red

Thermocouple:             Positive            as per ANSI MC 96.1 (Yellow)
                                    Negative           as per ANSI MC 96.1 (Red)

Instrumentation Question And Answer

                                                                                                                                                                                                                                                                                                       1.             What is QA/QC?
Ans:   QA/QC means, “Quality Assurance / Quality Control” The purpose of this (QA/QC) is to establish the sequence of requirement for the quality of material, quality of works, its inspection, and records.
                                                                                                                                                                                                                                                                                                                
2.             What is the MMG Quality Control Management System?
Ans: ISO 9001 ~ 2000

3.             What is the Quality Control?
Ans:   Quality Control “Those activities and techniques used to achieve and maintain the quality of product, process or service”.

4.             What is Quality Control Plan?
Ans:   Quality Plan “Document Specification which procedures and associated resources shall be applied by whom and when to specific project, product, process or contract”.

5.             What is non-conformity?
Ans:   Non-conformity “Non-fulfillment of requirement”. (Complete failure of a system, or controls, which result in completely unsatisfactory goods or services being provided).

6.             What is the Specification?
Ans: Governing Document Acceptance Criteria.

7.             Who are the responsible for Quality?
Ans: Everybody within all organization.

8.             What is the basic responsibility of a QA/QC personal?
Ans: To ensure execution of works and comply fully as per standard and approved specs.
                                                                                                                                                                                                                                                                                                                
9.             What is the basic required document for a QA/QC personal?
Ans:   The basic required documents for a QA/QC personal are as following.
ITP (Inspection Test Plan): To conduct the quality check (Inspection of Witness, Surveillance and Hold Point) etc.
RFI: To conduct the inspection of completed work.
QR (Quality Record): To maintain the quality records of completed works etc.
NCR: To issue warning in case of serious violation of standard.
WP (Work Procedure): Standard procedure to execute the works.
P & ID: As a reference to ensure that the work is as per standard drawing.
MTC: To ensure that material comply the PES standard specs.
Calibration Report: To ensure parameters are function checked as per IDS.
PP (Project Plan): To ensure that the instruments are installation as per P & ID and PP as per convenience.
Hook-up: To ensure that the remote connection of pneumatic is done correctly.
Wiring Diagrams: To ensure that wiring is done correctly
ILD: To ensure that the sequential wiring is done correctly.
IDS/ISS: To ensure that the instruments comply with the basic requirement.
QCO: To issue a warning in case of little violation and observation.
DR: Discrepancy Report.
                                                                                                                                                                                                                                                                                             
10.          What are QA/QC’s ITP and QCP? Give brief?
Ans:   ITP: This procedure informs about the kinds of quality check (surveillance, inspection, witness or hold pints) means quality of works is being done in proper sequences.

QCP: This procedure addresses the activities and requirement in details.