|
Last week I posted the requirements for workers verifying a Zero Energy State (ZES) and it was ALL about operators and NOT electrical workers. This post I will explain the EXTRA steps that "qualified electrical workers" MUST DO BEFORE they begin their electrical work.
I will use the OSHA regulation for electrical work...1910.333 "Selection and use of Work Practices". In this standard, it states the following:
1910.333(b)(2)(iv) Verification of deenergized condition. The requirements of this paragraph shall be met before any circuits or equipment can be considered and worked as deenergized.
1910.333(b)(2)(iv)(A) A qualified person shall operate the equipment operating controls or otherwise verify that the equipment cannot be restarted.
1910.333(b)(2)(iv)(B) A qualified person shall use test equipment to test the circuit elements and electrical parts of equipment to which employees will be exposed and shall verify that the circuit elements and equipment parts are deenergized. The test shall also determine if any energized condition exists as a result of inadvertently induced voltage or unrelated voltage backfeed even though specific parts of the circuit have been deenergized and presumed to be safe. If the circuit to be tested is over 600 volts, nominal, the test equipment shall be checked for proper operation immediately after this test.
Notice that (A) above is much like the what an operator will do as part of their LOTO; but electrical workers, and I should stress QUALIFIED ELCTRICAL WORKERS, are REQUIRED to use test equipment to test circut elements and electrical parts to VERIFY ZES. See part B above.
Many facilities still do not have Electrical Safety Related Work Practices to cover the activities of their electrical workers and VERY FEW LOTO programs will distinguish the procedures for ZES verification for electrical workers vs. the operator who runs the equipment. Most LOTO programs use language that instructs the authorized employee to try and start the machine/equipment using the normal start buttons and makes no mention of electrical workers using test equipment to test circuit elements and electrical parts to VERIFY ZES.
OSHA will not use 1910.147 to cite for this program/procedural defeciencies, but instead use 1910.333(b)(2)(iv)(B). Bottom line...Qualified Electrical Workers MUST use test equipment to VERIFY ZES BEFORE they begin work.
|
SAFTENG Safety Info Posts
Comments
The only times I can say for certain that a qualified electrical worker will have to "meter the source" to verify absence of energy ( e.g. Zero Energy State) are:
1) if the worker who will be doing the work is actually working on the electrical source or
2) if the machine/equipment was not running when the authorized worker arrived. By this I mean that is the equipment was NOT operational to begin with, then using the start/stop button is not an actual means of verifying ZES since the machine would not even start before the isolation took place. A Qualified Electrical Worker would have to meter the electrical to verify ZES.
Does this answer your question?
Bryan
RSS feed for comments to this post