CT Saturation

[chris kennedy]

Anybody have a link to how long a CT can operate without being under load or shorted before a dangerous situation occurs?

Thank you.

 

[djohns6]

I have personally seen an open circuited CT fire up . It was instantaneous .

 

[electricalperson]

Anybody have a link to how long a CT can operate without being under load or shorted before a dangerous situation occurs?

Thank you.

my guess is it can operate as long as nobody touches the ends of the leads maybe someone smarter than me will answer

 

[electricalperson]

I have personally seen an open circuited CT fire up . It was instantaneous .

your smarter than i am :smile:

now that i think about it..isnt the insulaton only rated for a certain amount of voltage? if a CT is open and not shorted you will get thousands of volts so it will probably burn up quickly

 

[masterinbama]

It doesn't take much load or time in my experience. But I have personally only smoked one in my 30 years

 

[chris kennedy]

But I have personally only smoked one in my 30 years

That sounds like something a politician would say.

 

[masterinbama]

That sounds like something a politician would say.

I hate to say it I did inhale. Didn't have much choice my head was all the way in a 42"X 42" X 18" ct cabinet feeding wire when I knocked the lead loose. I hate it when the first guy uses the outside conduits and leaves the future spares in the back.

 

[cadpoint]

Root around:

GEC Durham Industries, Inc
Dartmouth, MS 02745 - USA

I'm sure they have the full boat of appliable CT's

 

[SEO]

Chris are you referring to the meter as the load on the CT's or the building as the load? I'm assuming that your referring to the meter. I've seen the problem happen at a bank where the electrician disconnected the meter from the coils without shorting arcoss them. He was very lucky the POCO was working on a service nearby and disconnected the power. The coil cabinet was buzzing like crazy. I don't know how long it takes to reach a dangerous level but I would think that the more bullding load the quicker it would happen.

 

[brian john]

Saw one go in a manner of minutes, the rest I found damaged during service or as part of an emergency call.

The one that blew was left open by the utility after replacement we powered up the service and there was a low pitch wine that went from low to unbearable high pitched as smoke started to fill the electric room. We were running.

 

[chris kennedy]

Chris are you referring to the meter as the load on the CT's or the building as the load?

The meter as the load. The meter on a 700A 208y/120 CTed service was knocked out of the meter base and hung up in the bent cover. The cover had 2 barrel locks at the bottom so I couldn't get at the shorting bars. The guy running the lift on that side of the building said he didn't do it. If that is fact, it may have been out of the base for a couple days. For this type service POCO would normally supply 300:5 doughnuts.

 

[LarryFine]

I hate it when the first guy uses the outside conduits and leaves the future spares in the back.

Just like KO's on a panel and wires on a multi-level neutral bus.