Current through Register Vol. 54, No. 50, December 14, 2024
Section 39.133 - Grounding transformer cases(a) The metal case or exposed frame of each transformer, reactance, and similar equipment, which is located where dampness or inflammable gas normally exists, or which is connected to a circuit operating at over 150 volts to ground, shall be permanently grounded.(b) Exception is permissible in locations free from inflammable gas, if the entire transformer is isolated or guarded as required for the highest voltage circuit connected with the transformer, and is plainly and conspicuously identified as of that voltage. This section cited in 34 Pa. Code § 39.201 (relating to storage batteries, transformers and lightning arresters).