T op Ele c t ric a l De sign
Que st ions & Answ e rs
1st Edition
Prepared by: Mahmoud Essam Hizzah
Date: January 2010
Country: Cairo - Egypt
Career Title: Electrical Design Engineer
, ﺑﺴﻢ اﷲ اﻟﺮﺣﻤﻦ اﻟﺮﺣﻴﻢ
"و ﻗﻞ رب زدﻧﻰ ﻋﻠﻤﺎ"
اﻟﺤﻤﺪ ﷲ و اﻟﺼﻼة و اﻟﺴﻼم ﻋﻠﻰ رﺳﻮل اﷲ ﺻﻠﻰ اﷲ ﻋﻠﻴﻪ و ﺳﻠﻢ
اﻣﺎ ﺑﻌﺪ
ﺗﻌﺘﺒﺮ أﻋﻤﺎل اﻟﺘﻮﺻﻴﻼت واﻟﺘﺮآﻴﺒﺎت اﻟﻜﻬﺮﺑﺎﺋﻴﺔ ﻓﻰ اﻟﻤﺒﺎﻧﻰ ﻣﻦ أهﻢ اﻟﺘﺮآﻴﺒﺎت ﻓﻰ ﻣﻌﻈﻢ اﻟﻤﺸﺮوﻋﺎت اﻟﺘﻰ ﻳﺘﻢ ﺗﻨﻔﻴﺬهﺎ ﻓﻰ اﻟﻮﻗﺖ
ﻼ ﻋﻦ دورهﺎ اﻷﺳﺎﺳﻰ ﻓﻰ اﻟﺤﻔﺎظ ﻋﻠﻰ اﻟﺤﺎﻟﻰ ،وﻗﺪ اﺗﺴﻊ ﻣﺠﺎل اﺳﺘﺨﺪاﻣﻬﺎ ﻟﺘﺸﻤﻞ ﺟﻤﻴﻊ اﻟﻤﻨﺸﺂت اﻟﻌﺎدﻳﺔ وآﺬﻟﻚ اﻟﻤﻨﺸﺂت اﻟﺨﺎﺻﺔ ﻓﻀ ً
ﺳﻼﻣﺔ اﻟﻤﺒﺎﻧﻰ واﻟﻤﻨﺸﺂت ﻣﻦ أﺧﻄﺎر اﻟﺤﺮﻳﻖ اﻟﻨﺎﺟﻢ ﻋﻦ ﻣﺨﺎﻃﺮ ﻋﺪم ﻣﺮاﻋﺎة اﻷﺻﻮل اﻟﻔﻨﻴﺔ ﻓﻰ ﺗﺼﻤﻴﻢ اﻟﺘﺮآﻴﺒﺎت اﻟﻜﻬﺮﺑﺎﺋﻴﺔ.
وﻗﺪ ﺻﺪرت ﻋﺪة اآﻮاد ﻋﺎﻟﻤﻴﺔ و ﻣﺤﻠﻴﺔ و اﻳﻀﺎ اﻟﻌﺪﻳﺪ ﻣﻦ اﻟﻜﺘﺐ و اﻟﻜﺎﺗﻠﻮﺟﺎت اﻟﺘﻰ ﺗﺘﻜﻠﻢ ﻓﻰ ﺷﺄن أﺳﺲ ﺗﺼﻤﻴﻢ وﺷﺮوط ﺗﻨﻔﻴﺬ
اﻟﺘﻮﺻﻴﻼت واﻟﺘﺮآﻴﺒﺎت اﻟﻜﻬﺮﺑﺎﺋﻴﺔ ﻓﻰ اﻟﻤﺒﺎﻧﻰ.
و ﻗﺪ ﻓﻜﺮت ان اﺟﻤﻊ ﺑﻌﻀًﺎ ﻣﻦ هﺬﻩ اﻟﻤﻌﻠﻮﻣﺎت ﻓﻰ ﺷﻜﻞ ﺳﺆال و ﺟﻮاب ﻟﺘﻌﻈﻴﻢ اﻻﺳﺘﻔﺎدة ﻣﻦ هﺬا اﻟﻤﻌﻠﻮﻣﺎت و ﻟﺘﻜﻮن ﺑﻤﺜﺎﺑﺔ
ﻣﻠﺨﺺ ﺳﺮﻳﻊ ﻷﺳﺲ اﻟﺘﺼﻤﻴﻢ اﻟﻜﻬﺮﺑﻰ و ﻳﺴﻬﻞ اﻟﺮﺟﻮع اﻟﻴﻪ.
اﻋﺘﻤﺪت ﻓﻰ ﺗﺤﻀﻴﺮى هﺬﻩ اﻷﺳﺌﻠﺔ ﻋﻠﻰ اﻟﻌﺪﻳﺪ ﻣﻦ اﻷآﻮاد و اﻟﻤﺮاﺟﻊ و ﺑﻌﺾ اﻟﺨﺒﺮات اﻟﺴﺎﺑﻘﺔ .وﻟﻜﻦ ،ﺑﺎﻟﻄﺒﻊ هﺬا ﻟﻴﺲ آﺘﺎب
ﻋﻠﻤﻰ ﻳﻌﺘﻤﺪ ﻋﻠﻴﻪ وﻟﻜﻨﻪ ﺑﻤﺜﺎﺑﺔ ﺑﺪاﻳﺔ ﻟﻤﺴﺎﻋﺪة اﻟﻤﺒﺘﺪﺋﻴﻦ ﻓﻰ هﺬا اﻟﻤﺠﺎل.
هﺬا هﻮ اﻷﺻﺪار اﻷول و ﺳﻴﺘﻢ ﻋﻤﻞ اﺻﺪارات ﺟﺪﻳﺪة ﺑﻤﺸﻴﺌﺔ اﷲ ﻋﺰ و ﺟﻞ ﻟﺘﺼﺤﻴﺢ اﻳﺔ اﺧﻄﺎء وﻹﺿﺎﻓﺔ ﺑﻌﺾ اﻷﺳﺌﻠﺔ و
اﻟﻤﻌﻠﻮﻣﺎت اﻟﺠﺪﻳﺪة.
ﻓﻰ ﺣﺎﻟﺔ و ﺟﻮد اى ﺧﻄﺄ او اﺳﺘﻔﺴﺎر ارﺟﻮا ﻣﺮاﺳﻠﺘﻰ ﻋﻠﻰ هﺬا اﻟﺒﺮﻳﺪ :و ذاﻟﻚ ﻟﺘﻔﺎدى هﺬﻩ
اﻷﺧﻄﺎء ﻻﺣﻘًﺎ.
اﺳﺄل اﷲ ﻋﺰ و ﺟﻞ ان ﺗﻨﻔﻌﻨﻰ و ﺗﻨﻔﻌﻜﻢ هﺬﻩ اﻟﻤﻌﻠﻮﻣﺎت ﻓﻰ اﻟﺪﻧﻴﺎ و ﻓﻰ اﻷﺧﺮة.
وارﺟﻮا ﻣﻦ اﻟﺠﻤﻴﻊ اﻻ ﻳﺒﺨﻠﻮا ﺑﻨﺸﺮ هﺬﻩ اﻟﻤﻌﻠﻮﻣﺎت آﻰ ﺗﻌﻢ اﻟﻔﺎﺋﺪة ﻋﻠﻰ اﻟﺠﻤﻴﻊ .و اﻟﺪال ﻋﻠﻰ اﻟﺨﻴﺮ آﻔﺎﻋﻠﻪ.
و اﻟﺴﻼم ﻋﻠﻴﻜﻢ و رﺣﻤﺔ اﷲ و ﺑﺮآﺎﺗﻪ.
اﺧﻮآﻢ /ﻣﺤﻤﻮد ﻋﺼﺎم ﺣﺰﻩ
, T op Ele c t ric a l De sign Prepared by: Mahmoud Essam Hizzah
Que st ions & Answ e rs Electrical Design Engineer
1) Have you previously done design for electrical work?
o Yes
o No
If yes, the following two items must be answer
a- What facilities or buildings you designed?
o Commercial
o Residential
o Industrial
o Medical/Health Care
o Educational/Schools
o Hotels
o Power Plant/Stations
o Sports
o Exterior Site Work
o Others: Please specify:
b- What Standards or Norm you used in your design?
o French
o American
o British
o IEC
o Others: Please specify:
2) Have you previously done shop drawing (execution) for electrical (high current) work?
o Yes
o No
3) Are you familiar and have used the following computer software’s:
o MS Word
o MS Excel
o AutoCAD
o Lighting Calculation Programs: Please specify:
o Voltage Drop Calculation Programs: Please specify:
o Short Circuit Calculation Programs: Please specify:
o Others: Please specify:
-1-
st
1 Edition Best Wishes
, T op Ele c t ric a l De sign Prepared by: Mahmoud Essam Hizzah
Que st ions & Answ e rs Electrical Design Engineer
4) What are the de-rating factors considered in cable installation?
Answer:
- Ground Temperature de-rating factor
- Air Temperature de-rating factor
- Burial Depth de-rating factor
- Soil Thermal Resistivity de-rating factor
- PVC Rated Temperature de-rating factor
- Trefoil or Flat Formation de-rating factor for three & single core cables laid direct in ground
- Trefoil Formation de-rating factors for multi-core cables laid direct in ground
- Reduction factors for groups of more than one multi-core cable in air to be applied to the current
carrying capacity for one multi-core cable in free air
- Reduction factors for groups of more than one circuit of single core cables to be applied to the current
carrying capacity for one circuit of single core cables in free air
5) What are the types of contracts? State the difference between them?
Answer:
- Lump Sum
- Re-measured
- Cost Plus
6) What are the precautions to be taken in mind when selecting an emergency feeder running next to another
feeder fed from normal supply?
Answer:
- Type of the used designed cable should be taken into consideration regarding its properties & to be of
higher fire resistance.
7) What is the national color code of a three phase circuit?
Answer:
- Red for phase (A)
- Yellow for phase (B)
- Blue for phase (C)
- Black for neutral (N)
- Yellow with green strip for protective earth (PE)
-2-
st
1 Edition Best Wishes
Que st ions & Answ e rs
1st Edition
Prepared by: Mahmoud Essam Hizzah
Date: January 2010
Country: Cairo - Egypt
Career Title: Electrical Design Engineer
, ﺑﺴﻢ اﷲ اﻟﺮﺣﻤﻦ اﻟﺮﺣﻴﻢ
"و ﻗﻞ رب زدﻧﻰ ﻋﻠﻤﺎ"
اﻟﺤﻤﺪ ﷲ و اﻟﺼﻼة و اﻟﺴﻼم ﻋﻠﻰ رﺳﻮل اﷲ ﺻﻠﻰ اﷲ ﻋﻠﻴﻪ و ﺳﻠﻢ
اﻣﺎ ﺑﻌﺪ
ﺗﻌﺘﺒﺮ أﻋﻤﺎل اﻟﺘﻮﺻﻴﻼت واﻟﺘﺮآﻴﺒﺎت اﻟﻜﻬﺮﺑﺎﺋﻴﺔ ﻓﻰ اﻟﻤﺒﺎﻧﻰ ﻣﻦ أهﻢ اﻟﺘﺮآﻴﺒﺎت ﻓﻰ ﻣﻌﻈﻢ اﻟﻤﺸﺮوﻋﺎت اﻟﺘﻰ ﻳﺘﻢ ﺗﻨﻔﻴﺬهﺎ ﻓﻰ اﻟﻮﻗﺖ
ﻼ ﻋﻦ دورهﺎ اﻷﺳﺎﺳﻰ ﻓﻰ اﻟﺤﻔﺎظ ﻋﻠﻰ اﻟﺤﺎﻟﻰ ،وﻗﺪ اﺗﺴﻊ ﻣﺠﺎل اﺳﺘﺨﺪاﻣﻬﺎ ﻟﺘﺸﻤﻞ ﺟﻤﻴﻊ اﻟﻤﻨﺸﺂت اﻟﻌﺎدﻳﺔ وآﺬﻟﻚ اﻟﻤﻨﺸﺂت اﻟﺨﺎﺻﺔ ﻓﻀ ً
ﺳﻼﻣﺔ اﻟﻤﺒﺎﻧﻰ واﻟﻤﻨﺸﺂت ﻣﻦ أﺧﻄﺎر اﻟﺤﺮﻳﻖ اﻟﻨﺎﺟﻢ ﻋﻦ ﻣﺨﺎﻃﺮ ﻋﺪم ﻣﺮاﻋﺎة اﻷﺻﻮل اﻟﻔﻨﻴﺔ ﻓﻰ ﺗﺼﻤﻴﻢ اﻟﺘﺮآﻴﺒﺎت اﻟﻜﻬﺮﺑﺎﺋﻴﺔ.
وﻗﺪ ﺻﺪرت ﻋﺪة اآﻮاد ﻋﺎﻟﻤﻴﺔ و ﻣﺤﻠﻴﺔ و اﻳﻀﺎ اﻟﻌﺪﻳﺪ ﻣﻦ اﻟﻜﺘﺐ و اﻟﻜﺎﺗﻠﻮﺟﺎت اﻟﺘﻰ ﺗﺘﻜﻠﻢ ﻓﻰ ﺷﺄن أﺳﺲ ﺗﺼﻤﻴﻢ وﺷﺮوط ﺗﻨﻔﻴﺬ
اﻟﺘﻮﺻﻴﻼت واﻟﺘﺮآﻴﺒﺎت اﻟﻜﻬﺮﺑﺎﺋﻴﺔ ﻓﻰ اﻟﻤﺒﺎﻧﻰ.
و ﻗﺪ ﻓﻜﺮت ان اﺟﻤﻊ ﺑﻌﻀًﺎ ﻣﻦ هﺬﻩ اﻟﻤﻌﻠﻮﻣﺎت ﻓﻰ ﺷﻜﻞ ﺳﺆال و ﺟﻮاب ﻟﺘﻌﻈﻴﻢ اﻻﺳﺘﻔﺎدة ﻣﻦ هﺬا اﻟﻤﻌﻠﻮﻣﺎت و ﻟﺘﻜﻮن ﺑﻤﺜﺎﺑﺔ
ﻣﻠﺨﺺ ﺳﺮﻳﻊ ﻷﺳﺲ اﻟﺘﺼﻤﻴﻢ اﻟﻜﻬﺮﺑﻰ و ﻳﺴﻬﻞ اﻟﺮﺟﻮع اﻟﻴﻪ.
اﻋﺘﻤﺪت ﻓﻰ ﺗﺤﻀﻴﺮى هﺬﻩ اﻷﺳﺌﻠﺔ ﻋﻠﻰ اﻟﻌﺪﻳﺪ ﻣﻦ اﻷآﻮاد و اﻟﻤﺮاﺟﻊ و ﺑﻌﺾ اﻟﺨﺒﺮات اﻟﺴﺎﺑﻘﺔ .وﻟﻜﻦ ،ﺑﺎﻟﻄﺒﻊ هﺬا ﻟﻴﺲ آﺘﺎب
ﻋﻠﻤﻰ ﻳﻌﺘﻤﺪ ﻋﻠﻴﻪ وﻟﻜﻨﻪ ﺑﻤﺜﺎﺑﺔ ﺑﺪاﻳﺔ ﻟﻤﺴﺎﻋﺪة اﻟﻤﺒﺘﺪﺋﻴﻦ ﻓﻰ هﺬا اﻟﻤﺠﺎل.
هﺬا هﻮ اﻷﺻﺪار اﻷول و ﺳﻴﺘﻢ ﻋﻤﻞ اﺻﺪارات ﺟﺪﻳﺪة ﺑﻤﺸﻴﺌﺔ اﷲ ﻋﺰ و ﺟﻞ ﻟﺘﺼﺤﻴﺢ اﻳﺔ اﺧﻄﺎء وﻹﺿﺎﻓﺔ ﺑﻌﺾ اﻷﺳﺌﻠﺔ و
اﻟﻤﻌﻠﻮﻣﺎت اﻟﺠﺪﻳﺪة.
ﻓﻰ ﺣﺎﻟﺔ و ﺟﻮد اى ﺧﻄﺄ او اﺳﺘﻔﺴﺎر ارﺟﻮا ﻣﺮاﺳﻠﺘﻰ ﻋﻠﻰ هﺬا اﻟﺒﺮﻳﺪ :و ذاﻟﻚ ﻟﺘﻔﺎدى هﺬﻩ
اﻷﺧﻄﺎء ﻻﺣﻘًﺎ.
اﺳﺄل اﷲ ﻋﺰ و ﺟﻞ ان ﺗﻨﻔﻌﻨﻰ و ﺗﻨﻔﻌﻜﻢ هﺬﻩ اﻟﻤﻌﻠﻮﻣﺎت ﻓﻰ اﻟﺪﻧﻴﺎ و ﻓﻰ اﻷﺧﺮة.
وارﺟﻮا ﻣﻦ اﻟﺠﻤﻴﻊ اﻻ ﻳﺒﺨﻠﻮا ﺑﻨﺸﺮ هﺬﻩ اﻟﻤﻌﻠﻮﻣﺎت آﻰ ﺗﻌﻢ اﻟﻔﺎﺋﺪة ﻋﻠﻰ اﻟﺠﻤﻴﻊ .و اﻟﺪال ﻋﻠﻰ اﻟﺨﻴﺮ آﻔﺎﻋﻠﻪ.
و اﻟﺴﻼم ﻋﻠﻴﻜﻢ و رﺣﻤﺔ اﷲ و ﺑﺮآﺎﺗﻪ.
اﺧﻮآﻢ /ﻣﺤﻤﻮد ﻋﺼﺎم ﺣﺰﻩ
, T op Ele c t ric a l De sign Prepared by: Mahmoud Essam Hizzah
Que st ions & Answ e rs Electrical Design Engineer
1) Have you previously done design for electrical work?
o Yes
o No
If yes, the following two items must be answer
a- What facilities or buildings you designed?
o Commercial
o Residential
o Industrial
o Medical/Health Care
o Educational/Schools
o Hotels
o Power Plant/Stations
o Sports
o Exterior Site Work
o Others: Please specify:
b- What Standards or Norm you used in your design?
o French
o American
o British
o IEC
o Others: Please specify:
2) Have you previously done shop drawing (execution) for electrical (high current) work?
o Yes
o No
3) Are you familiar and have used the following computer software’s:
o MS Word
o MS Excel
o AutoCAD
o Lighting Calculation Programs: Please specify:
o Voltage Drop Calculation Programs: Please specify:
o Short Circuit Calculation Programs: Please specify:
o Others: Please specify:
-1-
st
1 Edition Best Wishes
, T op Ele c t ric a l De sign Prepared by: Mahmoud Essam Hizzah
Que st ions & Answ e rs Electrical Design Engineer
4) What are the de-rating factors considered in cable installation?
Answer:
- Ground Temperature de-rating factor
- Air Temperature de-rating factor
- Burial Depth de-rating factor
- Soil Thermal Resistivity de-rating factor
- PVC Rated Temperature de-rating factor
- Trefoil or Flat Formation de-rating factor for three & single core cables laid direct in ground
- Trefoil Formation de-rating factors for multi-core cables laid direct in ground
- Reduction factors for groups of more than one multi-core cable in air to be applied to the current
carrying capacity for one multi-core cable in free air
- Reduction factors for groups of more than one circuit of single core cables to be applied to the current
carrying capacity for one circuit of single core cables in free air
5) What are the types of contracts? State the difference between them?
Answer:
- Lump Sum
- Re-measured
- Cost Plus
6) What are the precautions to be taken in mind when selecting an emergency feeder running next to another
feeder fed from normal supply?
Answer:
- Type of the used designed cable should be taken into consideration regarding its properties & to be of
higher fire resistance.
7) What is the national color code of a three phase circuit?
Answer:
- Red for phase (A)
- Yellow for phase (B)
- Blue for phase (C)
- Black for neutral (N)
- Yellow with green strip for protective earth (PE)
-2-
st
1 Edition Best Wishes
