(1) A licensee shall not be entitled to prescribe any special form of appliance for utilising energy supplied by him, or, save as
Provided 3[ in any conditions made under sub- section (2) or] by section 23, sub- section (2), or by section 26, sub- section (7), in any way to control or interfere with the use of such energy: Provided that no person may adopt any form of appliance, or use the energy supplied to him, so as unduly or improperly to 2[ interfere with-
(a) the safety or efficient working of a licensee' s electric supply- lines or other works; or
(b) the supply of energy by the licensee to any other person].