Insulation resistance test on length of SWA cable

[telectrix]

somebody mentioned viga. that was good enough. if they's have said "------" then that would have taken the thread in a totally new erection direction.

 

[TJ Anderson]

So what was the reason Tel?

It's gotta be worth just disconnecting the conductors to prove it and carrying out an IR on the cable only.

If the cable tests clear, then for your own interest, IR test the equipment you have disconnected l&n to earth at 250v test voltage. That way you won't damaging anything and you will find out what is giving you that reading.

 

[TJ Anderson]

So what was the reason Tel?

As Pete said, It's gotta be worth just disconnecting the conductors to prove it and carrying out an IR on the cable only.

If the cable tests clear, then for your own interest, IR test the equipment you have disconnected l&n to earth at 250v test voltage. That way you won't damaging anything and you will find out what is giving you that reading.

 

[Toneyz]

My initial thoughts were to disconnect but being that we were in a school it was difficult to leave doors unlocked while I got a wrench.
Does anyone have any experience with these Schneider MCCB boards you install the MCCB and tighten it and the head snaps off can you get these MCCB's out again and reinstall?

 

[TJ Anderson]

My initial thoughts were to disconnect but being that we were in a school it was difficult to leave doors unlocked while I got a wrench.
Does anyone have any experience with these Schneider MCCB boards you install the MCCB and tighten it and the head snaps off can you get these MCCB's out again and reinstall?

Yes, you can redo them. They set correct torque when they snap off the first time. Same as the old MCCB's in Merlin Gerin Panel Boards. You need a 17mm metric socket to undo it, and a torque wrench when you do it back up. What size MCCB is it?

 

[Nickzx6]

Ive seen similar on a new install on a treatment works. Turned out that a thin piece of masking type tape had been put across the top of the isolator (to avoid anything dropping in I suppose) which hadn't been removed when cable was installed. It tracked just enough to give a less than satisfactory IR reading but not enough for dead short.

 

[ipf]

Ive seen similar on a new install on a treatment works. Turned out that a thin piece of masking type tape had been put across the top of the isolator (to avoid anything dropping in I suppose) which hadn't been removed when cable was installed. It tracked just enough to give a less than satisfactory IR reading but not enough for dead short.

Had it been energized previously or were you doing the initial test? If you were, as you obviously know, that shows up a good reason for initial testing ......if not, someone slipped up badly, as you also know. It's a bit rough, though...…...or rouge, as one well known poster might say.

 

[Nickzx6]

Had it been energized previously or were you doing the initial test? If you were, as you obviously know, that shows up a good reason for initial testing ......if not, someone slipped up badly, as you also know.

Initial testing stage, far from being energised at that point. As you say though, highlights why the tests are so important