CT Shunts

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boyle78

boyle78

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new hampshire
I've been working on a project that involves shunting CT's in order to pull the meters. Some have been automatic bypass, some via inspection board, some can be shunted in a CT cabinet, and still some have to be shunted in the transformer. I wish I could tell you the Cal rating of my PPE, but I don't know (I totally know that this is my responsabilty and I will be looking at the tags asap). My concern is me being in the transformer next to the 480v paddles while shunting the ct's...should I really be doing this live? The arc flash tables and reqirements are confusing to me to say the least.....but it seems that the fault current from the transformer is way higher than any PPE can handle...How do the rest of you do it?
 
boyle78 said:
I've been working on a project that involves shunting CT's in order to pull the meters. Some have been automatic bypass, some via inspection board, some can be shunted in a CT cabinet, and still some have to be shunted in the transformer. I wish I could tell you the Cal rating of my PPE, but I don't know (I totally know that this is my responsabilty and I will be looking at the tags asap). My concern is me being in the transformer next to the 480v paddles while shunting the ct's...should I really be doing this live? The arc flash tables and reqirements are confusing to me to say the least.....but it seems that the fault current from the transformer is way higher than any PPE can handle...How do the rest of you do it?
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You mean shorting of CT secondaries to pull meters? Using shorting blocks?? Your post is not very clear, please be more specific about the system.
 
zog said:
You mean shorting of CT secondaries to pull meters? Using shorting blocks?? Your post is not very clear, please be more specific about the system.
Click to expand...

Most of the ct's have had blocks on them...some didn't and I made some alligator jumpers to do the same thing. I WAS getting into the secondary side of the transformer doing this...I only have myself to blame for putting myself in potential harms way. My arclfash gear is 8.3 cal rated....not even close to anything that would protect me if a fault happend in the trans. If there isn't an auto bypass behind the meter, or ct cabinet, I'm shutting the building down.
 
I still have no idea of what this is. 480V? 69,000V? Something in between?? What type of gear? Meters? etc...

Hard to help at all with out knowing what you are working on.

Reason I bring this up, my guys short CT secondaries to pull meters and realys nearly every day, there is little to no arc flash hazard. So when you talk about this I assume you are doing something similar, but good chance I am assuming wrong.
 
zog said:
I still have no idea of what this is. 480V? 69,000V? Something in between?? What type of gear? Meters? etc...

Hard to help at all with out knowing what you are working on.

Reason I bring this up, my guys short CT secondaries to pull meters and realys nearly every day, there is little to no arc flash hazard. So when you talk about this I assume you are doing something similar, but good chance I am assuming wrong.
Click to expand...

mostly 480v....very few 208v. it's not the shorting of the ct's that bothers me...it was me having my hands IN the transformer,inches away from the paddles with unisulated nut drivers in order to shunt the ct's going to the meter so I can pull it to replace with a programmable,digital reader type.
 
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