Master Electrician Strikes Again

This will give you a good laugh. We get called out after hours to a plant and the life blood system for that plant is down. They have a burned up power supply. We get there and start checking and the power supply for the process and the 1746-P2 are both burned up. We find another power supply and a P2 from our shop and start going back together. While we are checking things out and adding some needed fuse protection I listen to the master electrician jabbering. He recounts that when he found the breaker it was hooked to 3 machines so being a good fellow he goes to the supply store and gets another breaker and splits the load up by moving the panel to it's own breaker. When he flips the breaker on it trips at once. When he walked around to the panel there was smoke billowing out if it. He is saying that it must have been an old power supply that just gave it up. After we get it all tested out and running again it's real late at night. So we go home to get some rest. About 3am I sit up in my bed and smack my forehead and say I know what happened! Then I go back to sleep.

The next morning we go back down to the plant and trace the conduit to the panel. When we open the panel door the following warning in red is printed on inside.

WARNING DO NOT HOOK 120 TO RED PHASE
RED PHASE IS THE HIGH LEG!

To listen to this guy talk he knows everthing and did everything an electrician could do. Guess he can't read...

John

OUTSTANDING!

1). Give him a raise.
2). Promote him to Maintenance Manager where he can't do anymore harm.
3). encourage him to runfor elected office. Specially since things will get screwed up anyway. And he might get assassinated.
4). Perhaps a career in Law Enforcement. (Adam 12, can you read?)

regards.....kck

Okay, help me out here, 'cause I'm missing the punchline. I'm an ME, not an electrician.

Did he hook up the second breaker to the "red leg", thus putting 480V into the control cabinet where 120V was expected ?

And how did you replacing the power supply and adding a fuse make a difference... unless you also moved the source back to the original breaker ?

Ken,

On 240V delta transformers the neutral is a grounded center tap between the A and C phases. This means that you can get 120 V from A to CT, and from C to CT, but from B to CT, you have 208V. The B leg is refered to as the high leg.

http://en.wikipedia.org/wiki/High_leg_delta

Big John T said:

. He recounts that when he found the breaker it was hooked to 3 machines so being a good fellow he goes to the supply store and gets another breaker and splits the load up by moving the panel to it's own breaker. John

Click to expand...

Hard to be believe he would not do something as basic as measure the voltage before engaging the breaker.

RE:
############
WARNING DO NOT HOOK 120 TO RED PHASE
RED PHASE IS THE HIGH LEG!
############

According the the Sec. 110.15 of the NEC the high leg should be marked with orange tape or other means.

curlyandshemp said:

Hard to be believe he would not do something as basic as measure the voltage before engaging the breaker.

Click to expand...

Or read the warnings on the panel...

Or wonder why all the B phase slots are blank...

John

Big John T said:

Or reading the warnings on the panel...

Or wonder why all the B phase slots are blank...

John

Click to expand...

Maybe thats why he is a master, does not have to second guess his work

Ian

dogleg43 said:

RE:
############
WARNING DO NOT HOOK 120 TO RED PHASE
RED PHASE IS THE HIGH LEG!
############

According the the Sec. 110.15 of the NEC the high leg should be marked with orange tape or other means.

Click to expand...

I didn't even look in the panel to see if it was marked with orange. Most electricians will put orange on either side of the red around here...

John

dogleg43 said:

According the the Sec. 110.15 of the NEC the high leg should be marked with orange tape or other means.

Click to expand...

This was part of a common question on many Master Electrician exams. List the colors that are called out in the NEC.

I did something like this once. I hooked up a GFCI to the high leg, turned on the breaker, boom. But then I was only 16.

News Flash!!!!!

Master Sparky lets the smoke out of a power supply shutting the plant down.

Film at 10.

I am not a fan of grounded delta power. I learned this color code, Red is HOT as in 208, black is High 110, white is low 110 and green is ground.

I think it's time for a bunch of us to pool (not POLL) our money together and invest in a few hundred more shares of "CONSOLIDATED RESIDENT SMOKE".


They have a new process too! they're using Flux Capacitors with Muffler Bearings for more efficient production.

BTW, when working on any type of Government projects, you should only use "RED TAPE".

Ken Roach said:

Okay, help me out here, 'cause I'm missing the punchline. I'm an ME, not an electrician.

Did he hook up the second breaker to the "red leg", thus putting 480V into the control cabinet where 120V was expected ?

And how did you replacing the power supply and adding a fuse make a difference... unless you also moved the source back to the original breaker ?

Click to expand...

I'm with you on this Ken.

caseyk lmao!!!


what I ain't sure of was why was this stuff blowin up in the first place and gave him a reason to move power over?

sparx said:

what I ain't sure of was why was this stuff blowin up in the first place and gave him a reason to move power over?

Click to expand...

My GUESS is that he took it upon himself to split off the three machines into their own branches, and then it started going downhill.

That, or they have some of those "mystery wires". It's a mystery how they got to the wrong place.

Or that new guy, "I. Dunno" worked on it.

Who broke this???? "I Dunno".

Hey, it's snowing today! Wish I was in good enough shape to go out "Curling".

Oh Well, there's always the "Ninth End".