Live-dead-live test

[I^2R]

Hi everyone, first post here.

Trying to aggregate the various safety requirements together, I'm stuck on one point. Standards state that live electrical work must not be done except for very specific exceptions. Fine, I understand the logic in that.
Safety standards also mandate that equipment be tested to verify it's de energized (duh). The established / recommended / accepted practice is live-dead-live with the live test performed on a voltage similar to that in question to verify correct operation of the test equipment.
So where does one get the "live" voltage for the meter test? Wouldn't this test fly in the face of the rules? :-?

 

[iwire]

So where does one get the "live" voltage for the meter test? Wouldn't this test fly in the face of the rules? :-?

You are going to love this ......... :grin:



You are supposed to fully suit up with the appropriate PPE level to do the test you are asking about.

 

[I^2R]

Soooo.... what your saying is;
Every time we work on something de-energized, it comes with an "unavoidable" hot work situation, the exact thing that we are told can be avoided in almost every situation. So there is in effect no such thing as performing your work de-energized because we need to verify the function of the tester to confirm the de-energized state of the equipment in question?

I'm all for shutting stuff down, but I'm trying to draft a safety policy for the company that makes sense, this part baffles me.

 

[jim dungar]

Soooo.... what your saying is;
Every time we work on something de-energized, it comes with an "unavoidable" hot work situation, the exact thing that we are told can be avoided in almost every situation. So there is in effect no such thing as performing your work de-energized because we need to verify the function of the tester to confirm the de-energized state of the equipment in question?

I'm all for shutting stuff down, but I'm trying to draft a safety policy for the company that makes sense, this part baffles me.

The basis is:
Assume everything is live, therefore PPE required, until is is verified as de-energized.

Put on your PPE
'live check' your meter
check the 'de-energized' circuit
'live check' your meter
Remove your PPE

 

[hillbilly1]

Keep in mind too, that if the disconnecting means is built into the cabinet, such as a conveyor CC, the lugs and wires on the line side are still "live", so PPE would still be required while working in it, unless the feeder to the cabinet is disconnected before the cabinet.

 

[billsnuff]

my take

my take

live dead live

I'm in an industrial setting. So if I have to verify that a 480vac panel is dead.
I find the nearest 110 duplex and verify that the meter is functioning properly, then test the 480 as if it were live and retest the meter at the duplex.

live dead live is to verify that your meter is functioning properly. insurance to prove the dead part is realy dead.

 

[zog]

You are going to love this ......... :grin:



You are supposed to fully suit up with the appropriate PPE level to do the test you are asking about.

You are suited up anyways to test the dead circuit, the circuit is treated as live until proven otherwise, per OSHA rules. So you are not suiting up just for the live part of the test.

 

[zog]

live dead live

I'm in an industrial setting. So if I have to verify that a 480vac panel is dead.
I find the nearest 110 duplex and verify that the meter is functioning properly, then test the 480 as if it were live and retest the meter at the duplex.

live dead live is to verify that your meter is functioning properly. insurance to prove the dead part is realy dead.

If your meter has an auto ranging scale you can do it this way, if you need to change the scale to go from 120V to 480V you need to use a test source on the same scale.

Also the meter needs to be CAT III rated (Or IV)

 

[zog]

Hi everyone, first post here.

Trying to aggregate the various safety requirements together, I'm stuck on one point. Standards state that live electrical work must not be done except for very specific exceptions. Fine, I understand the logic in that.
Safety standards also mandate that equipment be tested to verify it's de energized (duh). The established / recommended / accepted practice is live-dead-live with the live test performed on a voltage similar to that in question to verify correct operation of the test equipment.
So where does one get the "live" voltage for the meter test? Wouldn't this test fly in the face of the rules? :-?

Read these yet?
http://forums.mikeholt.com/showthread.php?t=99114

Welcome to the forum

 

[I^2R]

Read these yet?
http://forums.mikeholt.com/showthread.php?t=99114

Welcome to the forum

Yup, read them Ad nauseam. Just missed any discussion on this particular point.

Looks like the PPE goes on for the test.

Thanks.