EARTHING CONCEPTS

 EARTHING CONCEPTS 

1. TNC system 

2. TNC-S system 

3. TNS system 

4. TT system 

5. IT system 

IR VALUE FOR ELECTRICAL CABLE & WIRING

 

IR Value for Electrical cable and wiring:

• For insulation testing, we need to disconnect from panel or equipment and keep them isolated from power supply. The wiring and cables need to test for each other ( phase to phase ) with a ground ( E ) cable. The Insulated Power Cable Engineers Association (IPCEA) provides the formula to determine minimum insulation resistance values.
• R = K x Log 10 (D/d)
• R =IR Value in MΩs per 1000 feet (305 meters) of cable.
• K =Insulation material constant.( Varnished Cambric=2460, Thermoplastic Polyethlene=50000,Composite Polyethylene=30000)
  D =Outside diameter of conductor insulation for single conductor wire and cable
• ( D = d + 2c + 2b diameter of single conductor cable )
  d – Diameter of conductor
  c – Thickness of conductor insulation
  b – Thickness of jacket insulation

HV test on new XLPE cable (As per ETSA Standard)

Application	Test Voltage	Min IR Value
New cables – Sheath	1KV DC	100 MΩ
New cables – Insulation	10KV DC	1000 MΩ
After repairs – Sheath	1KV DC	10 MΩ
After repairs – Insulation	5KV DC	1000MΩ

11kV and 33kV Cables between Cores and Earth (As per ETSA Standard)

Application	Test Voltage	Min IR Value
11KV New cables – Sheath	5KV DC	1000 MΩ
11KV After repairs – Sheath	5KV DC	100 MΩ
33KV no TF’s connected	5KV DC	1000 MΩ
33KV with TF’s connected.	5KV DC	15MΩ

IR VALUE OF SUBMERSIBLE MOTOR

 IR Value of Submersible Motor:

IR Value of Submersible Motor
Motor Out off Well (Without Cable)	IR Value
New Motor	20 MΩ
A used motor which can be reinstalled	10 MΩ
Motor  Installed in Well (With Cable)
New Motor	2 MΩ
A used motor which can be reinstalled	0.5 MΩ

HR & Admin ISO Internal Audit 2021 Report in Amara Raja Infra Pvt Ltd

 

Damage of 33KV/415V Transformer HT Bush & HT cable kit due to Moisture in HT Enclosure box

Here I enclosed the damages caused by Moisture inside the HT cable box

REASONS FOR MOISTURE 

•  Improper installation of Gaskets
•  Improper tightness of Bolts and Nuts of Enclosure box 

This is a simple check if we are careless on this it causes the following major incidents in Transformer 

DAMAGE CAUSED DUE TO MOISTURE 

• Failure of cable kit due to moisture on kit which may cause flash over of cables 
• Failure of HT bush which may cause major oil leakage and flash over 
  

LIGHT COLOUR TEMPERATURE

Warm Light  (2000K-3000K):  Typically for ambient lighting in relaxation/leisure areas like Living Rooms, Hotel Lounges, Restaurants.

Neutral Light (3500-4500K): Typical for general purpose such as Offices, Lobbies, Classrooms, and Retail

Daylight White (5000-6000K): Typical for high task high visibility needs such as Workshops, Laboratories, Kitchens, and Manufacturing  

Cool White (5500-6500K): Typical for outdoor lighting such as street lights, parking lots, warehouses

MAGICIAN OF HOCKEY ( INDIAN NATIONAL GAME )

Major Dhyan Chand (29 August 1905 – 3 December 1979) was an Indian field hockey player widely regarded as one of the greatest in the history of the sport.^[4] He was known for his extraordinary goal-scoring feats, in addition to earning three Olympic gold medals, in 1928, 1932 and 1936, during an era where India dominated field hockey. His influence extended beyond these victories, as India won the field hockey event in seven out of eight Olympics from 1928 to 1964.

Follow this link to get more details 

Magician of Hockey