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Memo: New Tool Checkout Process

1 To: All field crews. From: Rosa Delgado, Operations Manager, Harlan Electric. Date: March 3. Subject: New tool checkout process.

2 Starting Monday, March 10, all power tools and testing equipment will be checked out through the tool room using a scan system. Over the past year we have lost or misplaced more than forty tools, including two cable pullers and several meters. Replacing them has cost the company money that could have gone to raises and new equipment. The new process is meant to show where every tool is at all times.

3 Here is how it will work. When you need a tool, bring your employee badge to the tool room window. The attendant will scan your badge and then the barcode on the tool. You will be asked which job the tool is going to. The tool is then listed under your name until it comes back.

4 When you return a tool, the attendant will scan it again and check it for damage. If a tool is broken, tell the attendant what happened. You will not be charged for normal wear or for damage that happens on the job. The goal is to get broken tools repaired quickly, not to blame anyone.

5 Tools that are not returned within five working days will appear on a weekly report sent to foremen. If a tool needs to stay on a job longer, ask your foreman to extend the checkout.

6 The tool room will now open at 6:00 a.m. instead of 6:30 a.m. so crews are not held up in the morning. Questions can go to me or to the tool room attendant, Gary Moss.

Site rules at the clinic expansion

1 Welcome to the Cedar Point Clinic Expansion project. The clinic will stay open to patients during construction, so this site has rules that may be stricter than those you have followed elsewhere. Every worker must attend a site orientation before starting work. These rules are covered at orientation and are posted at the main gate.

2 Check-in. All workers and visitors must sign in at the site trailer each morning and sign out when they leave. In an emergency, the sign-in sheet is used to account for everyone on site. If someone leaves without signing out, rescue crews may search the building for a person who is not there.

3 Protective equipment. Hard hats, safety glasses, high-visibility vests, and work boots are required beyond the gate at all times. Hearing protection is required in posted areas. Visitors who do not have their own equipment may borrow it from the trailer.

4 Clinic areas. The north wing of the building remains in use. Workers may not enter the north wing without an escort from the clinic's facilities staff. Noisy work, such as drilling into concrete, is allowed only before 8:00 a.m. or after 5:00 p.m., when the clinic is closed. Any shutdown of power or water that affects the north wing must be requested at least 48 hours in advance.

5 Housekeeping. Each trade is responsible for cleaning its own work area at the end of the shift. Scrap wire, packaging, and cut-off pieces of pipe must go in the marked bins. Walkways and exits must be kept clear at all times.

6 Incidents. Report every injury, near miss, and property damage to your foreman right away, no matter how minor. The foreman will notify the site superintendent, who completes the written report. Breaking these rules may result in removal from the site, and repeated violations may lead to a worker being barred from the project.

Cords and GFCI protection on the job site

1 Temporary power on a construction site often reaches tools through extension cords. Cords get stepped on, dragged across concrete, and run over by carts. Because of this rough use, a damaged cord is one of the most common electrical hazards a new worker will see.

2 Before plugging in a cord, look it over from end to end. Check for cuts or worn spots in the outer jacket. Make sure the plug has all of its prongs, including the round grounding prong. A cord that is missing its ground prong should be taken out of service right away. Tape is not a proper repair for a damaged jacket.

3 Cords on a job site should be plugged into outlets protected by a ground-fault circuit interrupter, or GFCI. A GFCI compares the current flowing out to a tool with the current flowing back. If some current is leaking away, possibly through a person, the device shuts off the power in a fraction of a second. It does not prevent every shock, but it can keep a shock from becoming deadly.

4 A GFCI only helps if it works. Most have a test button. Pressing it should cut the power, and pressing the reset button should restore it. If the power does not shut off during the test, do not use that outlet. Report it to your supervisor.

5 Finally, think about where the cord runs. Keep cords out of standing water, away from sharp edges, and out of doorways where a closing door can crush them. A few seconds of care can prevent a serious injury.

Why the Lights Came Back in That Order

1 When a winter ice storm swept through the town of Halbrook, nearly every home lost power within a few hours. Branches heavy with ice snapped and fell across lines, and several poles came down along the county road. By morning, residents were calling the utility and asking the same question: why was the hospital back on while their street was still dark? Some families went to stay with relatives. Others gathered at the school gym, which the town opened as a warming center.

2 The answer lies in how utilities plan their repairs. Crews do not simply start at one end of town and work their way across. Instead, they begin with the parts of the system that serve the most people. The first step is to check and repair the high-voltage transmission lines and the substations that feed the area. If those are damaged, no repair farther down the line will bring anyone's power back.

3 Next, crews repair the main distribution lines that leave each substation. Within this stage, they give priority to places that protect public health and safety, such as hospitals, water treatment plants, and emergency services. A single repair to a main line can restore power to thousands of customers at once. In Halbrook, the hospital had run on a backup generator through the first night, but a generator like that is not meant to carry a building for days.

4 After the main lines, crews move to smaller lines that serve neighborhoods and streets. Last come the repairs that affect only one or a few homes, such as a broken line running from a pole to a single house. These jobs can take as long as the larger ones while restoring power to far fewer people, so they come at the end.

5 In Halbrook, the last homes were restored four days after the storm. Some residents were frustrated, but many came to understand the plan once the utility explained it at a town meeting. One woman said afterward that she still had not enjoyed four days without heat, but she could see why the line to her house had waited behind the water plant.

Conductors and their coverings

1 When people talk about wire, they usually mean two things at once. One is the conductor, the metal that carries current. The other is the insulation, the covering that keeps that current where it belongs. Choosing wire for a job means thinking about both.

2 Copper is the most common conductor in buildings. It carries current well, bends without cracking, and holds up to repeated handling. Aluminum is lighter and costs less, so it is often used for large feeders and for utility lines. However, aluminum carries less current than copper of the same size. As a result, an aluminum conductor must be larger than a copper one to do the same job. Aluminum also expands and contracts more as it heats and cools, and it forms a surface layer that resists current. For these reasons, aluminum must be connected only with terminals and devices rated for it, and installers must follow the maker's instructions closely.

3 Insulation brings its own choices. Some coverings are made for dry locations only. Others are made to handle moisture, heat, sunlight or oil. The letters printed on the outside of a wire tell what the insulation is made for and what temperature it can stand. A wire that is fine inside a dry wall cavity may break down quickly if it is run through a wet underground conduit.

4 Heat is the main enemy of insulation. Current flowing through a conductor makes heat, and more current makes more heat. If a wire carries more current than it was sized for, the insulation can soften, crack or melt over time. Once that happens, the conductor may touch metal or another wire, causing a fault or a fire. This is why wire size, the load it will carry, and the conditions around it must all be considered together.

5 Color is a final part of insulation that matters on the job. Colors help workers tell conductors apart. In common practice, green or bare wire is used for equipment grounding, and white or gray marks the grounded conductor, often called the neutral. Other colors are used for the ungrounded, or "hot," conductors. Still, a careful worker never trusts color alone. Wires may have been installed wrong or re-marked by someone else, so testing remains the rule.

How a transformer changes voltage

1 Electricity leaves a power plant and travels many miles before it reaches a home. Along the way, its voltage is raised and lowered several times. The device that makes these changes possible is the transformer, and it has no moving parts at all.

2 A basic transformer has two coils of insulated wire wrapped around a shared core of iron. The coil connected to the power source is called the primary. The coil connected to the load is called the secondary. The two coils are not connected to each other by any wire. Energy passes between them through magnetism.

3 The process works like this. Alternating current flows into the primary coil and creates a magnetic field in the iron core. Because the current keeps reversing direction, the magnetic field keeps growing, shrinking, and reversing as well. This changing field passes through the secondary coil and produces a voltage in it. If a load is connected, current then flows in the secondary circuit.

4 The number of turns in each coil decides what happens to the voltage. If the secondary has more turns than the primary, the voltage goes up. This is called a step-up transformer. If the secondary has fewer turns, the voltage goes down, which makes a step-down transformer. A transformer cannot create energy, however. When it raises the voltage, the current available on the secondary side drops by about the same proportion, apart from small losses.

5 This trade between voltage and current explains why power lines carry electricity at very high voltages. Higher voltage means lower current for the same amount of power, and lower current means less energy is lost as heat in the long lines. Near homes and businesses, step-down transformers lower the voltage to levels that are safer to use.

6 Transformers depend on a changing magnetic field. A steady direct current, such as the current from a battery, produces a field that does not change, so a transformer will not work on it. The low hum heard near many transformers comes from the core, which vibrates slightly as the magnetic field reverses again and again.