Evelyn, the Electrician

When your dad owns a construction company, you grow up knowing a lot about how buildings are built. My dad started taking me to construction sites when I was in the seventh grade, but he wasn't telling me to go into any of the construction trades. He was just showing me what construction workers did and how hard they had to work while doing it.

He said they made good money, but most of them were pretty worn out by the time they reached retirement age. It was the hard, physical labor that did it. He wanted me to go to college so I could work at a desk instead of working outside when it was ninety-eight in the shade or cold enough the concrete required an additive so it wouldn't freeze before it could cure.

I ended up going to college to become an electrical engineer and found a job with an architectural firm that specialized in industrial and office buildings. As one of the electrical engineers there, I designed the power and lighting systems for buildings.

The funny thing about my job was that even though Dad thought I'd spend all my time at a desk, I spent about half my time on construction sites. Construction sites require electrical work from almost the time a track-hoe or dozer takes the first bite of soil from the site until the building gets a certificate of residency - the inspectors final approval of the building construction. I was on a job site a lot to explain the electrical drawings, to inspect what the electricians had done so far, and to walk around with the electrical inspector when he made his inspections.

On almost all new sites, the electrical service comes from the power company's high voltage lines through underground conduits to a set of main switchgear. That means those conduits have to go in the ground before any foundation work is done. Once the building is weather tight, the switchgear has to be installed and secured in place and then the feeders from the power company pole have to be pulled through the conduits and connected to the switchgear. Then the switchgear is connected to the transformers that bring the line voltage down to the voltage used by the equipment to be installed in the building.

Usually that voltage is 480 volts, three-phase, and the transformers feed a bank of high amperage circuit breakers. From those circuit breakers, the electricians run more conduits that feed bus bars in the ceiling of the building for the connection of equipment. There are also conduits from those circuit breakers to transformers and circuit breaker panels that bring the voltage down to the normal household voltages for offices and other low-voltage equipment. At that point, what's left is other conduits and wiring from those low voltage circuit breaker panels for lighting and receptacles.

Any mistakes along the way can result in at best a lot of rework and at worst, a major electrical system failure when the system is energized. You don't get second chances if there's a short circuit in a thirteen-thousand volt line. The arc from that short circuit can reach thirty-five thousand degrees, will vaporize any metal and other nearby materials, and create a sonic blast wave about equivalent to exploding a pound of TNT. Any one of those is enough to kill anyone within twenty feet of the arc.

Yes, there are safety suits that OSHA requires for people working around high voltages. They're made of heavy canvas-like material that is supposed to keep the wearer from catching fire in the event of an arc flash. They don't do anything for the blast wave. In many cases they only serve to help make sure there's enough of the person left to identify after a high voltage arc flash.

Without the safety suit, even a short circuit in the normal four-eighty volt circuit creates an explosion and a fireball that can kill or severely burn people. As the design engineer, I had to be there to make sure the electricians had wired everything according to my electrical drawings before the system was energized.

The electricians on most jobs were well-trained and experienced in the common skills of digging in conduit, running conduit, pulling wire, and wiring panels, receptacles switches and lighting. It was seldom that I found an error in an electrical system.

Now, most of the electricians I worked with were free-lancing, meaning they weren't regular employees of the electrical contractor. They'd watch the various job posting boards on the Internet and pick where they wanted to work next. Many would work jobs in northern states during the summer, but then take jobs in the South during the winter. They were an independent bunch and a lot of fun to work with because they had some neat stories to tell.

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I'd designed the electrical system from the power company pole down to every last receptacle and light fixture for a small warehouse and went to the site as soon as the contractor had finished leveling the building site. The electricians were laying out the path of the conduits from the power company pole to where the switch room was going to be and I had to make sure of three things before the concrete subcontractor could start any foundation work.

The placement of the conduits that came up out of the ground inside the building was critical. A conduit in the wrong place might not be discovered until the concrete floor was poured and the electricians attempted to place the switchgear. Correcting that error would mean ripping out a large section of the floor, rerouting the conduit, and then pouring the floor again.

Only one high voltage conduit was required on the job, but it ran under what was going to become a road around the building. That section of conduit had to be encased in concrete so heavy trucks wouldn't eventually collapse it, and I went to the site to make sure that job was done according to my design. That meant I had to get there before any concrete was poured.

I'd specified steel conduit as a riser from the pole down to the elevation the conduit was to be at going into the building, more steel conduit from the sweep, the elbow used to transition from vertical conduit to horizontal conduit, to across the proposed road and PVC conduit from there into the building. The steel riser was to protect the high voltage wiring from damage from lawn mowers and I used steel conduit to span the road because of a local code. I used PVC conduit for the rest of the run because PVC won't rust and it doesn't degrade over time like steel does. PVC is also a little easier to get any joints sealed against water intrusion.

In this case, I'd specified two, four-inch conduits from the pole to where the switchgear would be placed. I could have specified as small as three-inch conduits, but 500 MCM wire is pretty stiff and pulling it around corners is a lot easier in larger conduit. Considering the total cost of the project, the cost of the larger conduit wouldn't be significant.

One would hold the wiring from the pole to the switchgear. The other was a spare. It doesn't cost much to add a spare conduit when the first installation is being done, even if it's never used. It costs a ton to dig up an existing installation just to add one conduit.

Any conduit encased in concrete has to be supported by what are called "stools". Stools are pre-manufactured devices that keep conduits from sagging and also maintain a minimum distance between them.

I had a look and the number of stools was what I'd specified and the conduits were straight and level. All the joints looked properly done. They were just finishing up the forms that would keep the concrete in the area required. It all looked good, but I had a couple things I need to check before I authorized the pour.

The first thing I had to check was the soil compaction of the bottom of the trench. I found the lead electrician and asked to see the soil test data. He pointed to a woman standing beside the trench.

"Go see Evelyn. She keeps all the paperwork."

Evelyn didn't look like much. She had her red hair pulled back in a ponytail that stuck out the back of a ball cap with a fist holding a lightening bolt on the front. She had on the combination sunglasses/safety glasses that OSHA mandates for workers working outside in the sunshine so I couldn't really see much of her face other than her mouth. She was wearing a dark blue work shirt and work pants, neither of which fit her very well, and the standard electrician's work shoes.

I walked up and asked if she was Evelyn and she said yes. Then she smiled and asked me who I was and what I needed.

"I'm Mark Wright, the electrical engineer on this project. I need to see the soil data before I authorize the pour."

Evelyn smiled again.

"It's in our storage container over there."

She turned and started walking toward a row of steel shipping containers at one side of the site. They're the common way of storing materials secure and out of the weather on construction sites. They're cheap to rent, roomy, lockable, and easy to move around.

Evelyn unlatched the door, pulled it open, and then walked inside. A second later, four light bulbs came on. At some point, the electricians had run a temporary service to the storage container so they'd have lights inside.

That wasn't the only thing they'd done to the container, but their changes were pretty common for projects that were going to last for months. In the back half of the container were racks with parts and tools. The front half had been converted into a sort of office and lunchroom. There was a small table and four chairs, and on one sidewall was a desk and chair. There was even a small refrigerator humming away next to the desk. That desk was where Evelyn went next.

In a rack on top of the desk were several books and catalogues, one of which I recognized as the current NEC codebook. That was a good thing. Not all electricians keep up with the changes to the code that seem to happen every year. Usually they're minor changes, but not implementing a change can cause a rejection by an electrical inspector.

Evelyn opened the file drawer in the desk, fingered through the folders, and then pulled one out and handed it to me.

"You can look, but the compaction tests showed between ninety-six and ninety-seven. I checked before I let the dirt guys leave."

What she was talking about was how densely the soil had been compacted in the bottom of the conduit trench. Per the local ordinance, it had to be compacted to at least ninety-five percent or the weight of the concrete that encases the conduits and the load that drives over it will eventually compress the soil and cause the conduits to sag. That might cause one of the seals to break and allow water to infiltrate the conduit.

The test data looked good. The next thing I had to check was the fill material for the trench. Conduits need a stable bed to sit on and that bed is usually made up of rock or gravel of fairly small particle size, like maybe an inch across. It's also compacted to avoid future settling.

I checked the data on the initial fill and then the fill that went up the sides and over the top of the conduit except for the part that would be encased in concrete, and it all looked good.

I handed the file back to Evelyn and told her she'd done a good job. She smiled.

"It's good to hear that from somebody for a change. Keeping the files and doing the layout work and ordering materials is all the lead electrician will let me do. He doesn't think a woman can run conduits and wire panels. I keep the electrical drawings and if they need copies I request them from the design firm. I guess I'd be requesting them from you. I keep all the intermediate inspection paperwork too, so when you write up your report today, it'll end up in my file. I didn't spend two years in school, another two years as an apprentice and then pass the journeyman's test to be a secretary, but I guess it's OK. I still get paid scale and I don't have to get dirty.

"Oh, by the way, you got a phone number in case I need more prints? It'll be faster if I talk to you instead of some secretary in your print room."

I gave Evelyn my work number and then left the container and found the lead electrician and told him he could go ahead with the pour. A half-hour later a concrete truck pulled up. It took about fifteen minutes before the concrete was level with the top of the forms. I'd already checked to see that the forms were at the right distance from ground level.

There wasn't anything else to check that day, so I went back to my office and started on our next project. It was two days later that my desk phone rang. When I answered it, it was Evelyn.

"Mister Wright, you need to come out to the site. The concrete guys are laying out the foundation and our sweeps and risers aren't where they should be relative to the walls. I went out and measured to be sure, and something's definitely wrong. They're planning on pouring the footers tomorrow, so you need to come today. You probably should bring the foundation engineer with you too. They're not very happy with me and I need some help to figure out what's wrong."

When Jack and I got to the site, there were only a couple guys there sitting on a pile of dirt and drinking Gatorade. When I asked where everybody was, one of them pointed to the construction contractor's trailer.

"The electricians shut down the whole goddamned thing because they think we put the foundation in the wrong place. They're all up at the construction trailer tryin' to figure it out."

Jack and I drove to the contractor's trailer and even outside we could hear the yelling going on.

"I laid out the fucking footers myself and they're dead nuts on. Wouldn't expect any electrician to be able to use a tape worth a shit. I can't help it if you put your goddamned conduits in the wrong place. You need to move the fucking conduits while we're pouring the footers so we can get the block guys started."

We walked in the door and saw the lead concrete contractor and one of his men standing on one side of the table and the lead electrician and Evelyn standing on the other. The site foundation and electrical drawings were laying on the table. At the end of the table the general contractor's site supervisor was sitting in a chair looking bored.

Evelyn pointed to the electrical drawing then.

"Our risers are suppose to come up right where they are and they're supposed to be ten feet from the south wall so there's room to work behind the switchgear. I measured the distance to the wall at five feet short. That's not to code. You made a mistake and I think it's right here. You laid out the footers at three hundred and three feet from the property line when it should been three hundred and eight feet like my drawing says. I laid out the riser locations and I double checked them before we put them in the ground so I know I'm right."

I noticed the lead electrician was smiling but he wasn't trying to help Evelyn. When I shut the door, the contractor's site supervisor looked up and said, "Well, the experts are here. We'll let them tell us who made the mistake. You two want a bottle of cold water?"

We'd brought along copies of both drawings, so we laid them out of the table and started comparing. It took me a couple minutes to find the problem, and I knew it didn't happen at our shop. Our drawing checkers would have found it.

What had happened was the site electrical drawing Evelyn had showed the distance from the property line to the footer as three hundred and eight feet but the drawing I'd brought agreed with the foundation drawing at three hundred and three. The riser dimensions referenced the footer dimension, so they'd laid out the riser locations five feet closer to the wall than my drawings showed.

I moved my drawing to beside Evelyn's drawing and pointed to my drawing.

"Here's the problem. The electrical drawing is wrong by five feet, but I don't see how that could have happened because I haven't made any changes."

I touched Evelyn's drawing at the dimension in question then.

"I don't know if it's dirt or what but..."

I'd taken a drink of my water just before I touched Evelyn's drawing and the tip of my finger had picked up a little water that had condensed on the outside of the bottle. When I pointed to the drawing and touched the dimension in question, I noticed a tiny little smear of what looked like ink on what should have been the second numeral three of the dimension. That was impossible because our drawing printer is a laser printer and doesn't use ink.

I decided it would only make things worse if I pointed out that it looked like somebody had changed the three into an eight. That would just degenerate into finger pointing about who made the change.

I didn't think it was probably intentional anyway. The concrete contractor wouldn't have had access to the electrical drawing the electricians were using. There was no advantage for the electricians to change the drawing. Moving the risers would take them a day or two but they wouldn't get paid any more. I figured somebody had been using a ball point pen as a pointer and left a couple dots of ink on the electrical drawing.

"Well, this is the problem. You'll have to move the sweeps and risers but a couple horizontal sweeps will do that and won't violate code."

I looked at Evelyn then.

"Thank you for catching this, Evelyn. If you hadn't, we might be ripping up the concrete floor to move those risers. You tear up your drawing. I'll leave you this one to use."

The contractor's site supervisor said he was sorry we had to make a trip to the site and thanked us for figuring out what had happened. I said it was no problem and then left the trailer.

Jack and I figured that while we were there, we should take a look at the footer excavations so we drove over to the building site. I also wanted to see how much work would have to be done to move the sweeps and risers. That's what I was doing when Evelyn walked up beside me. She looked mad. She sounded mad too.

"Mister Wright, I'm going to get blamed for this, but it wasn't my fault. I'll never convince any of the other guys that it wasn't, but I just want you to know all I did was follow the drawing and I did double check my layout."

I waved my hand.

"Don't worry about it. I know it wasn't your fault and I've had worse things happen. This won't be hard to fix since you caught it early. Thanks again for doing that."

Evelyn smiled a little then.

"Well, that helps so thanks, but Mack, the lead electrician, said he'll have to check all my layouts from now on. What I imagine is going to happen is I won't get to do any more layouts."

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Once the conduits are in the ground, there's not much for electricians to do until the walls of the building are up and the roof is on. They spend the time ordering and receiving the materials they'll need to finish wiring the building. The switchgear will have been ordered as soon as the electrical contractor is awarded the job because the lead-time can be up to a year. Everything with a shorter lead-time like electrical panels, conduit and conduit fittings, wire, and everything else gets ordered during the wait. That can take a while because somebody has to look at each electrical drawing, measure distances, and calculate how many of what parts are going to be needed.

Because that's all that was going on, I didn't need to visit the site for a couple months. I was well into the design phase of our next building when I got another call from Evelyn, and she sounded upset.

"Mister Wright, would you approve a splice in the five hundred MCM feeders from the pole to the switch gear?"

The short answer to that question was no. Splices are potential failure points and since those conductors would be carrying about three hundred amps at almost thirteen thousand volts, a failure could be catastrophic. Even if no one got hurt, a short to ground at that voltage would probably blow the feeder conduits out of the ground.