Cheap, Easy to Implement, and Significantly Improves Safety. Maintenance Management responsibilities for your Team.
My experience is less than 30% of electricians get this right.
That statement is a little harsh, but it not all their fault:
1. Lack of Safety Policy is probably number one
2. Lack of proper tools
3. Lack of Training (All Electricians should have been trained, but refreshers never go a miss).
Remember “OFF AIN’T OFF UNTIL TESTED”
The Procedure is:
Identify ALL sources of supply are OFF
Visual Inspection of Test Instrument
Test Instrument for Function on known Supply
Conduct Measurement on Asset wearing Insulating Gloves & Face/Eye Protection
ReTest Test Instrument for Function on known Supply
If you leave the Work Area ReTest.
Some of the problems occur finding a “Known Supply” if the board has been Isolated. This forces the Test to be conducted on upstream known supply and higher fault current (Not Good).
Once a Test is skipped because of Production pressures this reinforces a “Trust its OFF” culture.
I like Proving Units, they provide a known supply right at the Work Area, they eliminate testing on higher fault currents, and they help to reinforce a Safety Culture.
Maintenance Managers its Cheap, Easy to Implement, and Significantly Improves Safety.
3Phi Reliability Ask for a Lock Out Tag Procedure.