NO: E-29021|62195|2025|Electrical(HQ)                                                                                                                                                                                                                                                                                                                                                                                  Dhanbad, Date:12.04.2025

DGMS APPROVAL NO.-453 of 1997(Renewal)

From

Director General of Mines Safety
Directorate General of Mines Safety,
P.O & Distt: Dhanbad - 826 016.

To

NANDINI CHAKRAVARTY, Mine Line Pvt. Ltd., 23, INDRANI PARK
West Bengal, Kolkata, KOLKATA, 700033

Subject:   Approval under Regulation 208 (3) of the Coal Mines Regulations, 2017 for flameproof Transwitch Unit, model no. 1900, 500 KVA, 6.6/1.1 KV or 550 Volts, Delta/Star, DYn 11 incorporated with Vacuum Circuit Breaker, type no. EX630BVTS (with contactor manufactured by reputed manufacturer and tested at CPRI) and LVCA FLP secondary chamber suitable for Restricted Neutral System manufactured by M/S Mine Line Pvt. Ltd., Kolkata conforming to IS/IEC 60079-1:2014 and IS/IEC 60079-0:2017 for use in belowground Coal Mines in India – Renewal thereof.

Madam,

Please refer to your online application No. E-29021/62195/2020/Electrical (HQ) dated 14.01.2025, on the above subject, CIMFR Test & Assessment Report No. IN/CIMFR/TR20/H100 dated 04.09.2020, CIMFR/FES/Cons./22-23/242 dated 21/06/2022, BIS License No. CM/L- 0893166 and other documents submitted therewith in this regard.

I, in the exercise of powers conferred upon Chief Inspector of Mines (also designated as Director General of Mines Safety) under Regulation 208(3) of the Coal Mines Regulations, 2017, hereby, renew the approval (DGMS Approval No. 453 of 1997) granted vide this Directorate's letter No. 333/963/EHQ dated 20.11.1997 for a further period of five years, i.e. up to 11.04.2030 for use in belowground Coal Mines in India. In the interest of safety, the OEM guidelines shall be adhered to, and OEM-supplied spares shall only be used while maintaining the apparatus. The conditions mentioned in the original approval and subsequent renewal letters, if any, shall be strictly complied with and the test reports of all the electrical apparatus covered under approval, conforming to the latest standards, shall be submitted within three months, if not submitted before.

Please note that application for renewal should be made at least three (03) months before the date of expiry of the approval.