Before working on an instrument or other device in a current transformer secondary circuit employes shall bridge the device with jumpers so that the circuit cannot be opened at the device. Employes shall not open such a circuit at meter connections until it has been elsewhere bridged.
34 Pa. Code § 39.455
This section cited in 34 Pa. Code § 39.451 (relating to general provisions); and 34 Pa. Code § 39.461 (relating to general requirements).