While handling signal lines, metal sheaths, or signal equipment employes shall avoid touching guy or span wires and supply lines or equipment, especially standing on or touching transformer cases, bangers or connections. While touching open signal lines employes shall avoid contact also with grounded parts such as sheaths and ground wires.
34 Pa. Code § 39.495
This section cited in 34 Pa. Code § 39.461 (relating to general requirements).