That makes sense - although I think the word you're looking for is "shuffle". Not the time or place for dance practice!
Surprise 220 V electrical
- Thread starter AndyG
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That makes sense - although I think the word you're looking for is "shuffle". Not the time or place for dance practice!
Wow, looks like a lot of folks don't understand a lot about electricity.
Whenever you remodel anything, turn off the power. I turn it off at the meter pan and lock it off. No telling if some numb-nuts will come along and turn it back on.
I did a project years ago at a plant that manufactured electronic components for the automobile industry; about 2,000 assembly line workers. I was installing some computers and was using APC uninterruptible power supplies (UPS). Every time I powered it on, it alarmed and shut down. Their IT mgr was watching and wanted to know what was wrong. I asked him to show me their transformer room. All the way in the back, down some stairs into a little, dark, concrete room. It was filled with racks of transformers, all humming away. Behind the transformers, I found a 1" diameter, copper ground rod sticking up out of the floor. About a foot above it were a couple of 4/0 cables, just hanging there. I thought, "That ain't right." We called the plant electrician who explained that the plant manager told him to cut those wires because the circuit breakers on the lights kept popping. They were using those old, huge, sodium vapor lights. Apparently, the transformers in the light fixtures had so much leakage current that they were actually energizing the ground circuit sufficiently to blow circuit breakers. I met with the plant manager and told him what I had seen and that I was documenting it, having it signed by witnesses, and sending it to his headquarters, GM (customer), the IBEW, and to OSHA; and that when one of his employees was killed by electrocution he was going to be liable. That scared him enough to reconnect the grounds and replace the ancient lighting system.
On a related topic, I always make sure all of the pipes and ducts in my house are grounded. People see metal and assume it's grounded. Assumptions can kill you. The old trick of grounding something new to a cold water pipe in the bathroom may no longer work. Many, many houses today are plumbed with PVC and/or PEX, neither of which can act as grounds.
My brother was an HVAC engineer working for a former, very large cellular telephone company in OP KS. He was up on a 30' extension ladder installing an air handler when he brushed against a fluorescent light fixture. He became the path to ground for a 230VAC delta V. He woke up on the ground with a wrist broken in several places and no memory of what happened. Fortunately, there were enough witnesses to testify as to what happened.
Change batteries in your multi meter at least once a year.
Remember the corollary to Murphy's Law: If something bad can happen, it will.
Whenever you remodel anything, turn off the power. I turn it off at the meter pan and lock it off. No telling if some numb-nuts will come along and turn it back on.
I did a project years ago at a plant that manufactured electronic components for the automobile industry; about 2,000 assembly line workers. I was installing some computers and was using APC uninterruptible power supplies (UPS). Every time I powered it on, it alarmed and shut down. Their IT mgr was watching and wanted to know what was wrong. I asked him to show me their transformer room. All the way in the back, down some stairs into a little, dark, concrete room. It was filled with racks of transformers, all humming away. Behind the transformers, I found a 1" diameter, copper ground rod sticking up out of the floor. About a foot above it were a couple of 4/0 cables, just hanging there. I thought, "That ain't right." We called the plant electrician who explained that the plant manager told him to cut those wires because the circuit breakers on the lights kept popping. They were using those old, huge, sodium vapor lights. Apparently, the transformers in the light fixtures had so much leakage current that they were actually energizing the ground circuit sufficiently to blow circuit breakers. I met with the plant manager and told him what I had seen and that I was documenting it, having it signed by witnesses, and sending it to his headquarters, GM (customer), the IBEW, and to OSHA; and that when one of his employees was killed by electrocution he was going to be liable. That scared him enough to reconnect the grounds and replace the ancient lighting system.
On a related topic, I always make sure all of the pipes and ducts in my house are grounded. People see metal and assume it's grounded. Assumptions can kill you. The old trick of grounding something new to a cold water pipe in the bathroom may no longer work. Many, many houses today are plumbed with PVC and/or PEX, neither of which can act as grounds.
My brother was an HVAC engineer working for a former, very large cellular telephone company in OP KS. He was up on a 30' extension ladder installing an air handler when he brushed against a fluorescent light fixture. He became the path to ground for a 230VAC delta V. He woke up on the ground with a wrist broken in several places and no memory of what happened. Fortunately, there were enough witnesses to testify as to what happened.
Change batteries in your multi meter at least once a year.
Remember the corollary to Murphy's Law: If something bad can happen, it will.
CreepinDeth
TJ Addict
Funny complacency story
I say “complacency” because all of us get adapted to our field of work, and sometimes trust things too much, and dont properly test. I work much higher voltages and ALWAYS test, so low voltage Im like “meh” ….and it bit me good
I had to demo, and redo our laundry room a few years ago. I have a 240VAC outlet on the floor. So I turned the breaker off, assuming the labeling was correct.
So I got all the old tile out, and backer boards, installed new Hardee backer boards, laid the new 12x24 tiles, and began grouting it. Now mind you, the dryer NEMA outlet is on the floor, with the plastic cover off. As I began grouting, you have to wet sponge it with 2 different sponges. A dirty sponge and a clean sponge
Welp, first time that wet sponge made contact with the metal contacts in the casing of that NEMA outlet WHAAAAAZZZAAAAAH WHOA BOY….i got the full 240volts and I yelled pretty damn loud enough to make my wife come see if I was ok.
Needless to say ALWAYS ALWAYS ALWAYS check dead before operating near a circuit. My complacency and trust in proper labeling (it wasnt) bit my ass good
I say “complacency” because all of us get adapted to our field of work, and sometimes trust things too much, and dont properly test. I work much higher voltages and ALWAYS test, so low voltage Im like “meh” ….and it bit me good
I had to demo, and redo our laundry room a few years ago. I have a 240VAC outlet on the floor. So I turned the breaker off, assuming the labeling was correct.
So I got all the old tile out, and backer boards, installed new Hardee backer boards, laid the new 12x24 tiles, and began grouting it. Now mind you, the dryer NEMA outlet is on the floor, with the plastic cover off. As I began grouting, you have to wet sponge it with 2 different sponges. A dirty sponge and a clean sponge
Welp, first time that wet sponge made contact with the metal contacts in the casing of that NEMA outlet WHAAAAAZZZAAAAAH WHOA BOY….i got the full 240volts and I yelled pretty damn loud enough to make my wife come see if I was ok.
Needless to say ALWAYS ALWAYS ALWAYS check dead before operating near a circuit. My complacency and trust in proper labeling (it wasnt) bit my ass good
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Yep, working for a major utility in California for 35+ years, it was a requirement to check for the dead circuit using live-dead-live test, and lockout-tag out, MANDATORY and documented! When I was working in a critical facility, the amount of work that had to be done planning and documenting step by step procedures, took way more time than actually doing the physical work.
you're 100% right. Most of my work is in control circuits that are almost always 24VAC or 30VDC, and when I'm in the field it's doing retrofits on live installations with basically zero downtime expected. I don't bother shutting off power except to avoid damaging something.
I mostly work at home and have most of the devices I use set up on a rolling cart for development and testing work, but when we're working on a new concept I usually go to the first couple of sites to help define the process and react to any unforeseen issues that pop up. Last year I was in a grocery store installing new controllers for a walk-in ice cream freezer and some refrigerated cases. The two for the walk-in were in a box about 10' in the air and there were storage racks right up to it where the ladder would only fit sideways so I was positioned awkwardly. One of them was giving me trouble so I went to swap them to see if the problem followed the device or not. The connectors are in the back and it was stuffed into the box really tight so my hand is jammed in there blindly, and in that moment I found out in the worst of ways that the original panel wiring tech had stripped too far going into the plug and left enough exposed conductor for me to get my finger on it AND simultaneously was reminded that these MF'ers aren't 24V like every other device I ever work on, they're 120V. Definitely not the worst thing to be shocked by but it's still not fun sideways at the top of a ladder with my hand jammed between pieces of sheetmetal.
I got down without saying a word to the other people around me and went for a walk.
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My late father was an electrician. He had MAJOR calluses on his hands. He'd measure voltage with them. One hand, callus on thumb to callus on pinky. "110! 110! OW! 220!"
CreepinDeth
TJ Addict
Correct
When you say “critical facility” first thought that comes to mind is a Nuke plant. Yes?? I do the field side, all substations, and switchgear using LOTO, and we work off switching routines to create ZOPs that go thru multiple level checks……and still they come out wrong
Im the last line of defense to ensure the ZOP is correct when I takeout/restore. So we have a similar backgroundYeah I do all 120VAC in my house live,
Ive ate enough of that it just tickles.
However now Im smart enough to use some gloves, and training my son so….gotta set a good example
However I do NOT recommend that to anyone else
Do it dead (and check dead) whenever feasible
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I have a buddy that ran a maintenance crew at a paper mill almost get killed by an arc flash incident. They were closing a breaker after doing PM's on a machine. Turns out one of the blades inside the breaker had fallen out and landed across two phases on the load side, PLUS the remote actuator they were using failed to actuate. The rest of the crew went to get another actuator and he was standing in his arc flash suit but his hood off, when the actuator suddenly closed the breaker and in an instant he found himself on the ground outside the room he had been standing in and without the hair on one side of his head. It continued to dump sparks and molten metal until someone else found the next interrupt upstream to shut it down, and it pulled so much current the power company actually called to see what happened.
He came back to work with a newfound passion for safety and ended up getting promoted out of maintenance and put in charge of safety for the entire mill. They ended up doing millions in renovations over the next couple of years to get the incident energy below a new target threshold.
Electricity is wild, you guys.
He came back to work with a newfound passion for safety and ended up getting promoted out of maintenance and put in charge of safety for the entire mill. They ended up doing millions in renovations over the next couple of years to get the incident energy below a new target threshold.
Electricity is wild, you guys.
Correct
When you say “critical facility” first thought that comes to mind is a Nuke plant. Yes?? I do the field side, all substations, and switchgear using LOTO, and we work off switching routines to create ZOPs that go thru multiple level checks……and still they come out wrong
Yeah I do all 120VAC in my house live,
Ive ate enough of that it just tickles.
However I do NOT recommend that to anyone.
We just lost a Jr lineman to a triplex it bit him below the gauntlets / gloves and he died on the line
Transmission and Distribution Control Center. Operators control the electric transmission and distribution for the grid. Each side separate from each other but inside the same building. Common equipment feeding the building (Generators, UPS's, Communications, etc) . Multiple utility inputs. Basically a no touch environment unless approved by many in Management. Even an annual Fire Alarm Inspection was a big deal, as getting everyone to agree on the time frame of the test was a challenge. One thing that I was introduced to a few years before I retired was Electrical Panels called "Layer Zero" electrical panels. They are what is considered "finger safe", whereas when opening the panel dead front there were no parts exposed to the buss that were larger than the diameter of a pencil. You could change out a circuit breaker without the lugs or buss being exposed to the person doing the work. Very nice panels, but very very expensive. We had to change out a 3 phase 50 amp breaker one time, and if my memory is correct, it was around $800 for the one breaker.
Man is it ever. Nothing to f around with. I became involved with Arc Flash training starting around 2008, and went to several NFPA 70E seminars/training until I retired in June of 21. We wore AF Clothing 100% of the time (Level 1 Clothing), along with EH rated footware. Most of the sites in my area that had such high incident level energy (480) were deemed no touch unless the utility feed was disconnected.
I'm a mechanical engineer in the power world. I stay away from the sparkies and their minions. It's hard enough some days not getting hurt by shit you can see on site. I don't need to mess with the stuff you can't see.
A guy I worked with at the Nuke plant when I was in college moved into his new house. It burned down the next week when someone turned on the one switch to the line someone had driven a nail through. He still had his old house that hadn't sold, but none of his stuff he just moved.
My grandparents built the place I grew up in. Not had it built, they built it. That old wiring from the 30s/40s was some sketchy stuff compared to new. Apparently expensive, because each room had ine light and one outlet. Which lead to some Christmas Vacation looking outlets until the kitchen remodel and addition.
A guy I worked with at the Nuke plant when I was in college moved into his new house. It burned down the next week when someone turned on the one switch to the line someone had driven a nail through. He still had his old house that hadn't sold, but none of his stuff he just moved.
My grandparents built the place I grew up in. Not had it built, they built it. That old wiring from the 30s/40s was some sketchy stuff compared to new. Apparently expensive, because each room had ine light and one outlet. Which lead to some Christmas Vacation looking outlets until the kitchen remodel and addition.
I'm a mechanical engineer in the power world. I stay away from the sparkies and their minions. It's hard enough some days not getting hurt by shit you can see on site. I don't need to mess with the stuff you can't see.
A guy I worked with at the Nuke plant when I was in college moved into his new house. It burned down the next week when someone turned on the one switch to the line someone had driven a nail through. He still had his old house that hadn't sold, but none of his stuff he just moved.
My grandparents built the place I grew up in. Not had it built, they built it. That old wiring from the 30s/40s was some sketchy stuff compared to new. Apparently expensive, because each room had one light and one outlet. Which lead to some Christmas Vacation looking outlets until the kitchen remodel and addition.
A guy I worked with at the Nuke plant when I was in college moved into his new house. It burned down the next week when someone turned on the one switch to the line someone had driven a nail through. He still had his old house that hadn't sold, but none of his stuff he just moved.
My grandparents built the place I grew up in. Not had it built, they built it. That old wiring from the 30s/40s was some sketchy stuff compared to new. Apparently expensive, because each room had one light and one outlet. Which lead to some Christmas Vacation looking outlets until the kitchen remodel and addition.
My son just started an electrician apprenticeship a week ago. Today is his 6th day on the job. I'm glad this thread came up. I'm going to have him read it. He's learning from a journeyman. Mostly new construction, but they're going back through homes that are ready to hand the keys over to the new owners and crap is not done right, and that by people who work for the same company in the same development, so they are walking in on stuff they don't know about. Consistency seems to be lacking, or just plain mistakes. You sometimes only get one shot working with electricity. No pun intended.
CreepinDeth
TJ Addict
Distribution load dispatchers and Bulk Power dispatchers are in dfferent buildings in different cities for us
Been to both, No windows, long shifts,
I enjoy the field , couldnt do that office thing
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Correct
When you say “critical facility” first thought that comes to mind is a Nuke plant. Yes?? I do the field side, all substations, and switchgear using LOTO, and we work off switching routines to create ZOPs that go thru multiple level checks……and still they come out wrong
Yeah I do all 120VAC in my house live,
Ive ate enough of that it just tickles.
However now Im smart enough to use some gloves, and training my son so….gotta set a good example
However I do NOT recommend that to anyone else
Do it dead (and check dead) whenever feasible
The trick to not getting hit by 120v at home is not having an audience and saying "i always wire this stuff live". Guaranteed you get bit in the next 30 seconds
CreepinDeth
TJ Addict
What voltage was the breaker??
Hes lucky
People dont realize it, but the bigger the voltages the bigger the BOOM. I tell people I work on bombs, because they are. Taking them OUT of service isnt as dangerous as putting them BACK into service if something is amiss. You never wanna close a high or medium voltage breaker standing near it. We defer all closing to the dispatchers , but if telemetry it down, we gotta do it local
When a distribution or transmission level breaker blow up, they can launch or detonate and sling nasty BIG chunks or throw 1000lb+ breakers out of the cubicles or into the air
Power transformers also are extremely dangerous if they blow. Pretty much anything in a substation is
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OP
This post is so good I know I’m going to read it over and over.
Electrical has never been my strength- but I sure don’t want it to be my fatal weakness.
The kicker on this one is it was not only hidden but not contacting something at all- Until it did.
Ultimately we found out it bit the freon line- no a/c for them.
Now we have units that are 12 to 14 years old that have essentially been hit by lightning as well.
OP
I don’t know . Likely we were dealing with around 40 Amps or better.
40, 41.....Whatever it takes.
600V. He didn't tell me the amps but from his description of the machine I'd be surprised if it wasn't in the 1000A range. And since it immediately melted shut and couldn't trip back open it was dependent on the next level up, which may have been the main service to the mill. I'm sure the total service feed for the mill would baffle me. He didn't mention the SCCR for the circuit either. Just that the incident energy was enough that if he hadn't been standing as far as he had, the shock wave would have hit him hard enough that the arc flash suit (the bomb tech looking thing, not just the flame retardant flight suit) would have just been fancy clothes.
I've never actually seen one of these so I'm foggy on how they work, but he described a remote actuator that they put on the breaker so they can stand at a safe distance when they close it. He was at that "safe" distance when it blew.