Telephone exchanges should not be installed where the maximum EPR at the site of the exchange is greater than 430 volts.
In case of telephone exchanges, which include a distribution sub-station, providing the power requirements for the telecom equipment, every effort should be made to obtain EPR figure less than 430 volts for all categories of HV earth systems, if necessary by directly coupling all earth systems (including the reinforcing mesh which forms part of the building structure) and supplementing existing earth systems with deep driven earth electrodes. It may be practicable to feed power to the sub-station through an underground metallic sheathed cable with a supplementary earth system and surge diverters (lighting arresters) at the transition point between overhead and underground power construction. Where, despite these measures it is not possible to achieve a figure of EPR below 430 volts the sub-station earth system should be removed to a location, which ensures EPR not greater than 430 volts.
4.3 Telecom Circuits Within/Passing Through the EPR Hazard Zone
Within the power system earthing hazard zone the telecom circuits should be provided in plastic insulated land unscreened plastic sheathed cable laid in rigid PVC conduit. To isolate the circuits from remote earth, all conductors should be provided with isolating links within the boundary. Accessible metal parts such as metal sheathing, frames, boxes etc must be connected to the earthing systems.
If there is PABX in the hazard zone, the earthing of PABX should be commoned to the power system earth. The telecom circuits should have isolating transformer.
Location of cable joints, terminals, pillars, cabinets, etc, which require personnel to work, should be avoided in the hazard zone. If it is unavoidable, a warning signs should be fixed and special work practices followed.
Telecom circuits should not be protected, for the purposes of mitigation of induced voltage due to power system earth faults, by using GD tubes between the conductors and earth in the hazard zone, as this results in the transfer of earth potential rise to the telecom circuits, when the protectors fire.
It may prove desirable in some cases to change the underground to overhead construction. In such cases or wherever overhead construction is felt desirable in EPR hazard zone, only wooden poles should be used.
When it is essential to provide a telephone connection within the EPR zone, the following precautions should be taken:
(i) The post carrying DP box from which drop-wire is drawn to provide telephone connection should be located outside the EPR boundary of 430V.
Self-supporting drop-wire without, support of GI wire, should be used.
If necessary, the drop-wire should be supported on wooden poles within the EPR zone.
Inside the building the drop-wire should be taken through PVC pipes to the telephone instrument.
Rosette should be installed on an ebonite plate fixed on the wall.
The telephone instrument should be placed on a wooden table, which in turn should be placed on a rubber mat so that a person using the telephone also stands on the rubber mat.
The wire drawn from rosette to telephone instrument at any point should not touch any portion of the building.
Battery eliminators should not be used while providing plan 103 facility in the building.
The purpose of all these precautions is to prevent the telephone instrument, its user and connecting link etc from coming in contact with hazardous voltage.
Precautions for Working Staff in EPR Hazard Zone.
When working on telecom circuits in hazard zone, telecom staff should insulate themselves from the earth by standing on an insulating mat having a specified insulation, withstanding voltage of at least 15 KV for one minute. Where practicable, insulated tools, gloves and footwear should also be used.
Wherever isolating links are provided for telecom circuits, the telecom staff should remove these links before attending to any work on the circuits.
In case of existing telecom network, wherever necessity arises, the details with respect to EPR will be obtained from concerned Power authorities and the matter referred to Power & Telecommunication Co-ordination Committee (PTCC) for suggesting necessary protective measures. For all new constructions due consideration should be given to the safety limits and aspects explained above so as to ensure the safety of telecom assets and personnel.
(i) PTCC code of practice for the protection of personnel and equipment against earth potential rises caused by high voltage power system faults, issued vide Director (ML), DOT, New Delhi letter No. 10-11/89-ML dated 10th May 1989.
APT booklet on EPR.
Introductory manual on co-ordination of Power & Telecom Systems (Australia).
Information about Electrical Inspectors and Statutory Provisions
(As per the Electricity Act 2003)
I Appointment of Chief Electrical Inspector and Electrical Inspector
The Appropriate Government may by notification, appoint duly qualified persons to be Chief Electrical Inspector or Electrical Inspectors and every such Inspector so appointed shall exercise the powers and perform functions of a Chief Electrical Inspector or Electrical Inspector under this Act and exercise such other powers and perform such other functions as may be prescribed within such areas or in respect of such class of works and electrical installations and subject to such restrictions as the Appropriate Government may direct.
(2) In the absence of express provision to the contrary in this Act or any Rule made thereunder, an appeal shall lie from the decision of a Chief Electrical Inspector or an Electrical Inspector to the Appropriate Government or if the Appropriate Government, by general or special order so directs to an Appropriate Commission.
ADDRESSES OF STATE ELECTRICAL INSPECTORS
1. Chief Electrical Inspector,
Government of Andhra Pradesh,
Hyderabad – 500 004.
2. Chief Engineer, Zone – II,
Public Works Department,
Government of Arunachal Pradesh,
Ita Nagar – 791 111.
3 Chief Electrical Inspector-cum-Adviser,
Government of Assam,
R.G. Barooah Road, Rajgarh Link,
Road No. 1, (Opp. Commerce College),
Guwahati – 781 003.
4 Senior Electrical Inspector,
Government of Bihar,
5. Chief Electrical Inspector,
Government of Gujarat,
Dwarkesh Building, 3rd Floor, Khanpur,
Ahmedabad – 380 001.
6. Chief Electrical Inspector,
Government of Haryana,
SCO No. 85-86,
Sector No. 17-D,
Chandigarh – 160 017.
7. Chief Electrical Inspector,
Shimla – 171 001.
8. Chief Electrical Inspector,
Governemnt of Kerala,
Housing Board Building,
Trivandrum – 695 001.
9. Chief Electrical Inspector,
Government of Karnataka,
K.R. Circle, P.B. No. 5148,
Bangalore – 560 001.
10. Chief Engineer (ES) &
Chief Electrical Inspector,
Government of Madhya Pradesh,
Satpura Bhavan, 3rd Floor,
Bhopal – 462 004.
11. Chief Engineer (Electrical)
Government of Maharashtra,
6th Floor, Bandra (East),
Mumbai- 400 051.
12. Chief Engineer (Power),
Governemnt of Manipur,
Imphal – 795 001.
Senior Electrical Inspector,
Government of Meghalaya,
Shillong – 795 001
Chief Engineer Power &
Government of Mizoram,
Aizwal – 796 001.
Kohima – 797 001.
Chief Electrical Inspector,
Government of Orissa,
3rd Floor, Heads of Deptt. Building,
Bhubaneswar – 751 001.
17. Chief Electrical Inspector,
Government of Punjab,
18. Chief Electrical Inspector,
Government of Rajasthan,
Subhas Marg ‘C’ Scheme,
Jaipur – 302 001.
19. Chief Electrical Inspector,
Government of West Bengal,
Directorate of Electricity,
1, Karish Mukherjee Road,
Kolkata – 700 020.
20. Chief Electrical Inspector,
Thiru, Vi. Ka. Industrial Estate,
Chennai – 600 032.
21. Director Electrical Safety,
Vidyut Khand II,
Behind Pick-up Building,
Lucknow – 226 010.
B. ADDRESSES OF CENTRAL ELECTRICAL INSPECTORS
Cief Electrical Inspector
Central Electricity Authority
Sewa Bhawan, R.K. Puram,
Superintending Engineer, (2) Superintending Engineer,
Regional Inspectorate Office, Regional Inspectorate Office,
AB-5, Safdarjung Enclave, Shastri Bhavan,
New Delhi. Chennai.
(3) Superintending Engineer, (4) Superintending Engineer
Regional Inspectorate Office, Regional Inspectorate Office,
Vidyut Bhavan, Zorem Nangrim Hills,
5th Floor, Panji, Shillong.
EXTRACTS OF IMPORTANT CLAUSES FROM THE ELECTRICITY ACT, 2003
Protection of Railways, Highways, Airports and Canals, Docks, Wharfs and Piers
No person shall in the generation, transmission, distribution, supply or use of electricity, in anyway injure any railway, highway, airports, tramway, canal or water-way or any dock, wharf, or pier vested in or controlled by a local authority, or obstruct or interfere with the traffic on any railway, airway, tramway, canal or water-way.
Protection of Telegraphic, Telephonic and Electrical Signaling
Every person generating, transmitting, distributing, supplying or using electricity (hereinafter referred to as the “operator”) shall take all reasonable precautions in constructing, laying down and placing his electric lines, electrical plant and other works and in working his system, so as not injuriously to affect, whether by induction or otherwise, the working of any line used for the purpose of telegraphic, telephone or electric signaling communication, or the currents in such wire or line.
Where any difference or dispute arises between the operator and the telegraphic authority as to whether the operator has constructed, laid down or placed his electric lines, electrical plant or other works, or worked his system, in contravention of sub-section(1), or as to whether the working of any wire, line or current is or is not injuriously affected thereby, the matter shall be referred to the Central Government and the Central Government, if it is of the opinion that the wire or line has been placed in unreasonable proximity to the electric lines, electrical plant or works of the operator after the construction of such lines, plant or works, may direct the operator to make such alterations in, or additions to, his system as may be necessary in order to comply with the provision of this section, and the operator shall make such alteration or additions accordingly:
Provided that nothing in this sub-section shall apply to the repair, renewal, or amendment of any electric line or electrical plant so long as the course of the electric line or electrical plant and the amount and nature of the electricity transmitted thereby are not altered.
Where the operator makes default in complying with the requirements of this section, he shall make full compensation for any loss or damage incurred by reason thereof, and, where any difference or dispute arises as to the amount of such compensation, the matter shall be determined by arbitration.
Explanation:- For the purposes of this section, a telegraph line shall be deemed to be injuriously affected if telegraphic, telephonic or electric signaling communication by means of such line is, whether through induction or otherwise, prejudicially interfered with by an electric line, electrical plant or other works or by any use made thereof.
Notice of Accidents and Inquiries
If any accident occurs in connection with the generation, transmission distribution, supply or use of electricity in or in connection with, any part of the electric lines or electrical plant of any person and the accident results or is likely to have resulted in loss of human or animal life or in any injury to a human being or an animal, such person shall give notice of the occurrence and of any such loss or injury actually caused by the accident, in such form and within such time as may be prescribed, to the Electrical Inspector or such other person as aforesaid and to such other authorities as the Appropriate Government may by general or special order direct.
The Appropriate Government may, if it thinks fit, require any Electrical Inspector, or any other person appointed by it in this behalf, to inquire and report:-
as to the cause of any accident affecting the safety of the public, which may have been occasioned by or in connection with, the generation, transmission, distribution, supply or use of electricity, or
as to the manner in, and extent to, which the provisions of this Act or rules and regulations made hereunder or of any license, so far as those provisions affect the safety of any person, have been complied with.
Every Electrical Inspector or other person holding an inquiry under sub-section (2) shall have all powers of a civil court under Code of Civil Procedure, 1908 for the purpose of enforcing the attendance of witnesses and compelling the production of documents and material objects, and every person required by an Electrical Inspector be legally bound to do so within the meaning of section 176 of the Indian Penal Code.
Exercise of Powers of Telegraph Authority in Certain Cases
The Appropriate Government may, by order in writing, for the placing of electric lines or electrical plant for the transmission of electricity or for the purpose of telephonic or telegraphic communications necessary for the proper co-ordination of works, confer upon any public officer, licensee or any other person engaged in the business of supplying electricity under this Act, subject to such conditions and restrictions, if any, as the Appropriate Government may think fit to impose and to the provisions of the Indian Telegraph Act, 1885, any of the powers which the telegraph authority possesses under that Act with respect to the placing of telegraph lines and posts for the purposes of a telegraph established or maintained, by the Government or to be so established or maintained.
ROLE OF PTCC and PTCC CLEARENCE
PTCC Manual 2009