Near fatality

[birdog37]

I heard today a lineman beat the widowmaker as he had 7970 volts go through him from one hand to the other....there was an old single primary bushing transformer in back yard-he had to climb the pole to hook up temporary. The case ground was broke and not visible to him. The x2 transformer bushing was not tied to the system neutral (that is a spec for our company, but evidently wasn't for the previous company which our company had bought out). The lineman proceeded to hook up the 2 hot legs to the open meter socket of the temporary service. When he went to hook up the neutral, he somehow got between the new service neutral and the X2 neutral. Understand this, the neutral to the x2 bushing was energized at full potential because the tank ground was broke from the primary neutral. The transformer also had 1 other service on it that was not in use. The lineman was transferred to hospital, had an EKG done and 6 hours later he walked out with only burn marks on both hands. This could have been prevented if he would have been wearing his secondary gloves and had verified that the tank ground was properly connected to the system neutral. (I know secondary gloves are rated for up to a 1000 volts, but have heard they are tested at 10,000). I have made it a practice to verify that the tank ground is intact ever since seeing the X2 bushing not being grounded effectively on transformers at another company. After he left the hospital he stated all he could think of was the video he watched the day before in company safety meeting - on not taking short cuts. One lucky family and wife to have him home tonight. God Bless and don't let your guard down.

[reppy007]

I heard today a lineman beat the widowmaker as he had 7970 volts go through him from one hand to the other....there was an old single primary bushing transformer in back yard-he had to climb the pole to hook up temporary. The case ground was broke and not visible to him. The x2 transformer bushing was not tied to the system neutral (that is a spec for our company, but evidently wasn't for the previous company which our company had bought out). The lineman proceeded to hook up the 2 hot legs to the open meter socket of the temporary service. When he went to hook up the neutral, he somehow got between the new service neutral and the X2 neutral. Understand this, the neutral to the x2 bushing was energized at full potential because the tank ground was broke from the primary neutral. The transformer also had 1 other service on it that was not in use. The lineman was transferred to hospital, had an EKG done and 6 hours later he walked out with only burn marks on both hands. This could have been prevented if he would have been wearing his secondary gloves and had verified that the tank ground was properly connected to the system neutral. (I know secondary gloves are rated for up to a 1000 volts, but have heard they are tested at 10,000). I have made it a practice to verify that the tank ground is intact ever since seeing the X2 bushing not being grounded effectively on transformers at another company. After he left the hospital he stated all he could think of was the video he watched the day before in company safety meeting - on not taking short cuts. One lucky family and wife to have him home tonight. God Bless and don't let your guard down.

Its a good practice to look for that case ground being attached to the transformer before you climb it,I have done that,cant say all the time.There has been one fatality here that I know of due to a case ground not being connected.

[T-Man]

Just to be clear here, If the x2 was not tied to a neutral and the tank ground was broken the tub was out of service?

I'd be sure in a safety meeting the next day we went over how the old company made their connections, I'd ask that any work being done on existing installations aquired from the old company be treated with utmost respect and all connections be visibly checked before any work was done to re-energize or re-congfiure. As with any lineconstruction the last person to work on equipment has the responsibility to not leave traps for the next man. And the next man has the responsibility to check over what he is working on and understand how it was meant to work to avoid getting into trouble like above.

Great news the fella in the story was spared a more tragic ending.

[lewy]

All of our single bushing transformers have a separate case ground & H2 is welded to the tank opposite the end of the winding, there is also a tank strap at X2 which gives us 3 separate connections to ground. This is all added redundancy so the transformer is not relying on 1 connection, because as you said if you rely on the 1 connection & it breaks, it is now sitting there at line potential.http://http://

[birdog37]

T-man yes it was still in service and not sure why he did not at least trip the secondary handle on the tub.These questions always come up when a near miss occurs.There was no cut-out on the original installation years ago.It could not of been said better thou why leave a trap for another lineman.Take the time and bring it up to Specs.The extra bonding points are great.Back in the day thou when this tub was hung they probably were thinking of cost.I wouldn't take the time to set up at every pole to change these but if your there and set up make it right.............

[busman]

(I know secondary gloves are rated for up to a 1000 volts, but have heard they are tested at 10,000).

"Secondary" gloves come in two varieties. Class 00 gloves are rated for 500 VAC and tested at 2,500 VAC. Class 0 gloves are rated for 1,000 VAC and tested at 5,000 VAC. Regardless, you can bet I'd rather grab 7,000 volts wearing either class of Secondary gloves, than bare-handed.

Mark

[birdog37]

Thanks for the info on the test,I was told 10,000 volts for the test.I will pass it on 5000.Your right about wearing something @ least,lucky lineman.At least he's able to learn from it.Remember learn from other peoples mistakes you will never live long enough to make them all yourself......