Sub:    Approval under Regulation 208 (3) of the Coal Mines Regulations, 2017 for flameproof  3.3 KV/1.1 KV, upto 2 MVA Transwitch unit with primary current 600 A and multiple outlets on the secondary side associated with other flameproof electrical equipment as mentioned in Annexure-I manufactured by M/s. Mine Line Pvt. Ltd., Kolkata for use in belowground Coal Mines – Renewal thereof.

Dear Madam,

Please refer to your online application No. E-29021/30650/2020/Electrical (HQ) dated 09.11.2020, offline application No. M20/DGMS/68 dated 19.10.2020 on the above subject and CIMFR/ERTL Test Reports as mentioned in Annexure-I, BIS License No. CM/L- 0893166 and other documents submitted therewith in this regard. 

I, in 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. 667 of 2013) granted vide this Directorate's letter No. 333/1955/EHQ dated 20.12.2013 for a further period of five years, i.e. up to 15.12.2030 for use in belowground Coal Mines.  The conditions mentioned in the original approval and subsequent renewal letters shall be strictly complied with. 

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

This  approval issued subjected to the conditions of Submission of test reports as mentioned in reply submitted to this office  in the online portal  on dated 20/11/2025 and 03/12/2025  shall be made within 03 months from the date of issue of this letter.

In case the above said test reports conforming to the latest versions of the standards mentioned in the reply letter not submitted within three months period, the issuing authority reserves the right to withdraw renewal approval.

The conditions mentioned in the original approval and subsequent renewal letters shall be strictly complied with. 

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

Your Faithfully, (UJJWAL TAH) Director General of Mine Safety - (HQ) Date :16/12/2025   Enclosure: Annexure-I.

                                                                                                                                                     Annexure - I

List of flameproof electrical equipment to be used with flameproof 3.3 KV/1.1 KV, upto 2 MVA Transwitch unit with primary current 600 A and multiple outlets on the secondary side manufactured by M/s. Mine Line Pvt. Ltd., Kolkata in belowground coal mines.