Electrical QC Notes of Saudi Aramco Part-3
101. What is chapter 4 in National Electrical Code (NEC)?
Ans. Equipment for General Use
102. What is chapter 5 in National Electrical Code (NEC)?
Ans. Special Occupancies
103. What is chapter 6 in National Electrical Code (NEC)?
Ans. Special Equipment
104. What is chapter 7 in National Electrical Code (NEC)?
Ans. Special Conditions
105. What is chapter 8 in National Electrical Code (NEC)?
Ans. Communication Systems
106. What is chapter 8 in National Electrical Code (NEC)?
107. In what article of the National Electrical Code (NEC) for Class 1, Class 2 and Class 3 Remote Control, Signaling and Power-Limited Circuits?
Ans. Article 725
108. What is the minimum pad mounting installation requirement of switchgear equipment placed a top level of a concrete above natural grade?
Ans. 100 mm
109. What is the minimum working clearance on all side of a switchgear?
Ans. 2 Meters
110. What is the minimum working clearance on equipment having doors or access panel?
Ans. 3 Meters
111. What are the switchgear outdoor enclosure requirements with in the perimeter of process unit?
Ans. NEMA 250/NEMA ICS 6 type 4, or NEMA type 3 Manufactured copper free cast aluminum (0.4 of 1% Max.) or IEC 60529 type IP66
112. What are the switchgear outdoor enclosure requirements outside the perimeter of process unit?
Ans. NEMA Type 3 or 4 0r IEC 60529 Type IP54
113. What is the enclosure requirement in outdoor Plant and other industrial areas located in severe corrosive environment?
Ans. NEMA Type 4X
114. Switchgear Bus shall be tested for insulation resistance test with a 1 Minute test (Phase to Phase and Phase to Ground) with KV Megohmmeter?
Ans. 1 KV
115. What term when the maximum current, in amperes, that a conductor can carry a continuously under the conditions of use without exceeding its temperature rating?
116. What does it mean if you are acceptable to the authority having jurisdiction?
117. A device intended to provide protection from the effects of arc faults by recognizing characteristics unique to arcing and by functioning to de-energized the circuit when an arc fault is detected?
Ans. Arc-Fault Circuit Interrupter (AFCI)
118. A generic term for a group of nonflammable synthetic chlorinated hydrocarbons used as electrical insulating media?
119. It is connected to establish electrical continuity and conductivity?
120. A reliable conductor to ensure the required electrical conductivity between metal parts required to be electrically connected?
Ans. Bonding Conductor or Jumper
121. The connection between two or more portions of the equipment grounding conductor?
Ans. Bonding Jumper, Equipment
122. A device designed to open and close a circuit by non-automatic means and to open the circuit automatically on a predetermined over current without damage to itself when properly applied with its rating?
Ans. Circuit Breaker
123. A device or group of devices that serves to govern in some predetermined manner, the electric power delivered to the apparatus to which it is connected?
124. A conductor having no covering or electrical insulation what so ever?
Ans. Conductor Bare
125. A separate portion of a conduit of tubing system that provides access through a removable covers to the interior of the system at a junction of two or more sections of the system or at a terminal point of the system?
Ans. Conduit Body
126. An enclosure designed for surface mounting that has swinging doors or covers secured directly to and telescoping with the walls of the box proper?
127. The ratio of the maximum demand of a system or part of a system to the total connected load of a system or the part of the system under consideration?
Ans. Demand Factor
128. A unit of an electrical system that carries or controls electric energy as its principal function?
129. The case of housing of apparatus?
130. Electrically connected to, or is, a source of voltage?
131. An unintentional, electrically conducting connection between an ungrounded conductor of an electrical circuit and the normal non-current carrying conductor metallic enclosure, metallic raceways, metallic equipment, or earth?
Ans. Ground Fault
132. What is the ground resistance requirement for solidly grounded systems above 600 Volts?
Ans. 1 Ohm
133. What is the ground resistance requirement for resistance grounded systems above 600 Volts?
Ans. 5 Ohms
134. What is the ground resistance requirement for systems under 600 Volts?
Ans. 5 Ohms
135. When transformers operated in parallel, the total circulating current shall not exceed % of the rated current of the lowest kVA rated transformer?
136. The values from transformer turns ratio (TTR) tests shall not deviate more than % from either the adjacent coils or the calculated ratio.
137. Transformer turns ratio on each tap. Deviation of not more than +/- % is allowed.
Ans. +/- 0.5%
138. What is the transformer test limit values for Dielectric strength D-877, KV, minimum?
Ans. 30 KV
139. What is the transformer test limit value for Color, D-1500 ASTM Units maximum?
140. What is the transformer oil physical characteristic for Visual Examination D1524?
Ans. Bright and Clear
141. What is the transformer test limit value for Acid Number D974, mg KOH/g, maximum?
Ans. .03 mg KOH/g
142. What is the transformer test limit value for Water Content, D 1533, ppm, maximum?
Ans. 35 ppm
143. What would be measure during cable High Potential Test or Hight-Pot test?
Ans. Leakage Current
144. What SAMSS does SF6 Switchgear Fabrication Requirements?
145. What kind of Oil we are normally used in power transformer?
Ans. Mineral Insulating Oil
146. What are the two types of power transformer oil?
Ans. Paraffin Based Transformer Oil & Naphtha Based Transformer Oil
147. What mean by PPM in unit measures of testing?
Ans. Parts per Millions
148. What is SF6?
Ans. Sulfur Hexafluoride