Short Radius Conduit Bender? The 128 Correct Answer

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The minimum bend radius is the smallest allowable radius that the cable may be bent. During installation, cables are bent or bent under various environmental conditions. In empty pipes or earth ducts, cables are often bent around a curve. Cables are also bent when a cable is pulled around a sheave, which is a pulley placed in a manhole to guide a cable around a bend.

Cables are made up of various components that can be damaged if bent too much and stress is placed on the cable. For example, when bending a medium voltage cable that consists of a copper tape shield, the cable can crack the outer sheath. To prevent cable damage, cable standards such as the National Electrical Code (NEC) and the Insulated Cable Engineers Association (ICEA) have specified minimum bend radius requirements.

Sand bending has been used to bend tubing of all sizes for decades. Not just little things. You need to wet it to make it compact, but one end (usually the long end away from the bend) needs to be left open whether you use heat or not. If you heat it when sealed it will explode and hot sand burns are no fun (ask a foundry worker). When you bend it, sand has to be shifted and go somewhere, so one end has to be left open.

If you make multiple bends, you’ll need to redeposit the sand between bends or you’ll buckle it. voice of experience. If you look at the intricate designs in F1 exhausts etc from the 70’s and 80’s (pre titanium days) they were all hand made from one piece of pipe.

Ever since wires were first run in conduit, electricians have bent conduit to get wires where they need to go. Early hand benders made it possible to bend pipes effectively without causing walls to collapse. Today, simple hand bender doesn’t look much different from these early models, but significant improvements have been made.

Several categories of benders are available. Mechanical benders are an improvement over simple bending tools, hydraulic benders are available for rigid tubing, and electric benders reduce the time it takes to make multiple bends on site. In addition, various methods are available for bending plastic pipes.

hand bender

For years, two basic models have been the standards for hand bender: Benfield models are made of iron with markings on the heads that provide reference points for bend angles, and Gardner-style benders are made of die-cast aluminum with built-in bubble levels in the 45-degree and 90-degree angles. Positions to allow accurate bends.

Damon Henderson, Greenlee Bender Product Manager, said, “Bend repeatability is very important for hand bender, so improvements have been made to allow users to more easily achieve consistent bend angles. Angle markings and sight lines are design features that provide a clear view of achieving the desired bend.

“Hand bending machines have also become lighter and still have a long service life.

“Aluminum models reduce weight over their iron counterparts, while still being able to handle the wear and tear that inevitably occurs on construction sites,” he said.

Dave Mueller, Senior Product Manager at Klein Tools, said, “Although bending techniques have remained essentially the same for several years, there is an ongoing goal to improve angular accuracy and consistency over the life of a bending machine. Over time, the materials used in bending machines – iron or aluminum – wear out under heavy use. A consequence of this wear can be deformation of the leading hook end which grips the line. This distortion can lead to inaccurate results.

[SB]”For ease of use, special markers/targets have been added on the bend head for commonly used bends, such as: Also, quick reference charts on the handle labels provide the required measurements for a variety of offset angles and lengths, saving time on the job.

“Differences in OD between EMT and IMC require the use of a one size larger bending head for IMC [thicker wall]. Due to the difference in wall thickness, thinner EMTs can be adjusted for minor corrections after bending. The thicker IMC cannot be adjusted. So this requires accurate bending the first time.”

Ken MacLachlan, President/Founder/Electrician of Rack-A-Tiers said, “We addressed the workflow and challenge of quickly and efficiently manufacturing a series of multi-bends in a row while maintaining a consistent shape.

“Our answer is a bending machine with a ‘stop’ attached to the bending head to create exact and repeatable bends every time; simplified multipliers engraved on the bender to place the stop before offsets and four-point saddles are made; special 22.5 and 45 degree marks engraved on the bender to place pipe bend marks; as well as standard degree markings for stop placement, used together to bend three-point saddles without reversing the line in the shoe. Handy reference charts for locating bend marks are attached to the handle.”

Other manufacturers that serve the electrical market and offer tube benders include Ideal Industries (www.idealindustries.com) with aluminum and ductile iron benders for 1/2″ and ¾” EMT tubing and ductile iron benders for 1″ and 1¾”. -inch EMT tubes ; Gardner Bender (www.gardnerbender.com), with ½- and ¾-inch aluminum head bender and iron-head hand bender for 1¼-inch EMT iron pipe; and Southwire Tools & Equipment (www.southwiretools.com), which offers three hand bender models: a 1-inch EMT steel head bender; ¾-inch EMT with aluminum head; and ½-inch aluminum-headed EMT bender.

Mechanical, electric and hydraulic bending machines and bending carriages

Mechanical bending machines still require human muscles to make bends, but several features improve productivity. Bending shoes are mounted on a two-wheeled carriage and mounted at a comfortable working height. Hydraulic benders are for rigid lines with power provided by manual or electric hydraulic pumps. Electric bending machines, available in different sizes and models, are designed for high production bending. Handy features include adjustable work positions, programmable capabilities to perform accurate repeated bends at the same angles, remote controls, and the ability to calculate layout measurements for different bends before work begins. Some models can accommodate IMC, rigid and rigid aluminum without changing shoes.

“Productivity is lost if too much time is spent moving, setting up and planning a bend,” said Henderson. “To solve the first two problems, electric bending machines have been improved to limit the time it takes to move and assemble. Hauling around multiple groups of shoes is a thing of the past as many bending machines offer reduced or single shoe operation. Changing from one pipe size and type to the next is almost seamless.

“With larger and heavier hydraulic bending machines, transporting and reassembling can be a huge waste of time. Recent improvements have mobilized these larger bending machines, allowing for convenient storage and quick dismantling and set-up.

“Benders can only bend so fast. Much of the productivity opportunity can be achieved by eliminating user error, reducing the need for manual calculations, and simplifying the bending process. Electric bending machines have now become smarter and can assist users in the planning phase before the bend is performed. Bender improvements now include line size detection; calculate where to mark the line; and built-in springback calculations.

“EMT and IMC need additional support rollers for squeezing when bending; Otherwise the quality of the bend can suffer and creases can appear on the inner bend radius. However, IMC differs from EMT in its setup calculations; IMC has various multipliers when calculating bends, including offset, take-up, springback, etc.,” Henderson said.

The Southwire Bendstation Pro workstation features a dual-bend shoe for ¾ and 1-inch EMT wire mounted on four casters for easy movement around job sites. The height of the work table is 36 inches with the ability to hold 900 feet of cord. An additional shelf is used to store tools and materials.

Gardner Bender sells three wheeled cart mounted bender and three electrically powered bender.

Bending PVC

Heat is often used to soften the plastic used to bend PVC pipe. There are also cold benders that do not use heat.

“Demand for curved PVC pipe is growing,” said Henderson. “For underground burials, PVC pipe offers a more cost-effective method of running cables and has a longer service life with minimal maintenance required in underground applications.

“Heaters and blankets can be used to evenly heat PVC tubing, making it pliable and allowing it to be bent into the required geometry by hand. To ensure even heating, open pipe ends can be sealed with PVC plugs. This is particularly critical in colder environments where airflow through the duct could cause erratic and uneven heating from ID to OD,” he said.

PVC Bendit offers a tool that is inserted into PVC Schedule 50 tubing and tubing and applies heat to allow bending.

“Internal heating with our product takes about five to seven minutes for the tool to heat up,” said Mike Warner, manager/co-owner of PVC Bendit. “Once hot, about another five to seven minutes to heat smaller diameter tubes. For 3 to 4 inch pipes, it can take about 15 minutes to heat up unattended.”

According to MacLachlan, bending PVC is challenging because the pipe doesn’t have to collapse when bent. The company’s cold-bending spring is inserted into the tube to support the walls during bending.

“The spring bender is simple, portable, and requires no electricity,” he said. “The user can cold bend rigid PVC pipe without [the] pipe collapsing or breaking. It’s faster and easier than cutting and gluing factory fittings. For smaller sizes, the spring is inserted into the tube and bent over one knee. Larger springs are ideal for maintaining tube integrity when using other bending methods. Ten sizes are available for 1/2″ to 4″ diameter tubing.”

Dan has been a licensed travel level electrician for 17 years. He has extensive experience in most areas of the electrical trade.

Read on to learn how to bend a 90° tube with EMT conduit. You will also learn how to bend a kick 90 and a double 45-degree 90. Jcmorris2 | Unsplash

What is a 90 degree bend in electrical conduit?

Bending EMT is one of the most common tasks for both commercial and industrial electricians, and it’s not difficult to learn. This article is for aspiring electricians to give them some pointers on using a hand bender to make a 90 degree bend in electrical wiring. More experienced electricians may be interested in another article on how to make a concentric bend.

There are three basic 90 degree bends: the single 90, a kick 90, and a double 45 90. Each has its uses and should be learned by the electrician; each is discussed separately in this article. Read and understand the pipe bending instructions here and try to get some “bones” (scrap pipes) from a job site to practice with. A little practice and you’ll be able to flex a 90 in no time.

How to make a 90 degree bend

A simple 90-degree bend in electrical conduit – that sounds simple, and it is, but there are a few considerations that need to be made. First on the list is the concept of deduction; This is a measure of how much the wire “shrinks” in length when a hand bender is used properly.

It is different for each bender size (½”, ¾”, and 1″ bender), and some brands of bender are also different. The most common deductions are 5″ for ½” tubing, 6″ for ¾” tubing, and 8″ for a 1″ tubing. Bender It is a function of the bend radius of the bender and cannot be changed The deduction for your bender should be stamped on the bender.

To use the deduction number, measure the distance to the very edge of the 90 and subtract the deduction number. If ½ inch pipe is being bent and the distance is 56 inches, mark the pipe at 51 inches; this is where the bending device is placed.

Insert the bender onto the pipe with the pipe mark on the bender arrow. There is some slight variation in the location of the arrow between different brands, but it is basically at the beginning of the bend of the bender. The bender must be oriented so that the tip of the bender is pointing toward the end of the pipe that you are measuring from. To put it another way, point the tip of the bender at the end of the pipe where the tape measure was hooked to measure.

With the pipe on the floor, apply firm foot pressure to the bender foot pedal and slowly move the bender handle toward the floor. Much of the bending pressure comes from the foot pedal – if not enough pressure is applied to the pedal, the line will buckle instead of making a smooth bend. When the line rises in the air, grab it with your free hand and apply a little pressure there to stabilize it.

It’s a good idea to stop bending just before it becomes a true 90 degree bend and check with a spirit level. It’s easy to add a few more degrees; not so easy to take something out. Note that the weight of the bender creates a small bend that disappears when the bender is removed and the tube springs back ever so slightly.

The above method works well for shorter lengths, but when a long measurement is required it will not work. For example, if the measurement is 110 inches with a length of 120 inches, the bender only has 10 inches to use. It is difficult if not impossible to make such a bend, especially on ¾ and 1 inch pipe. The answer is to turn the bender upside down and point the foot pedal at the end you are measuring from. Don’t use the trigger!

Mark the pipe at the desired full length and work the bender back onto the pipe. This time align the star on the side of the bender with the mark about halfway around the bender. Bend as before. This method of measuring and placing the bender is commonly referred to as “backbend”.

Bender size deduction 1/2″ 5″ 3/4″ 6″ 1″ 8″

Bending a 90 placement to bend a 90 when using the trigger. The bending machine is turned over and placed on the floor for the actual bending. 1/3

Bending a 90 degree bend

Bending a kick 90

A kick 90 is quite simply a 90 with an additional small bend in it that either raises or lowers the end of the 90. It can be used on a pipe leading up inside a wall, but that needs to be moved over and outside the wall when continuing past the 90 on the ceiling.

The same can be achieved with a 90° and an offset, but this requires additional bending and makes the wire more difficult to pull. Always limit the number of bends in a conduit to the fewest possible.

Bend the 90 first and pick a spot to add the little “kick” bend. The closer it is to 90, the more degrees are needed, but at the same time it looks downright odd if it’s too far from 90. Mark the pipe and place the bend mark at the mark for a standard 90 degree bend. Make sure the 90 is rotated the right way or the kick is bent the wrong way. Visualize the resulting line before bending, perhaps while holding it in the correct orientation.

Typically, kicks are bent to a specific measurement in inches, not degrees. With the bender on the pipe and ready to bend on the floor, apply pressure to the bender but just enough to tighten the pipe so it doesn’t slip or rotate. Using a level, check that the 90 end is level and measure from the floor to the top of the pipe 90. Measure how high the 90 is from the floor (see pictures).

Start bending and watch the tape measure carefully until the line is at the correct height. Be careful not to let the bender lean to one side; While this won’t change a bend already started, it will change the reading on the tape measure. The measurement to look for is the desired kick amount plus the first measured measurement.

For example, if the initial measurement is 1½ inches (a reasonable amount when the bender is only lightly tightened) and the desired kick is 4 inches, the final measurement to the top of the pipe should be 5½ inches. Also note that the side of the 90’s with the kick will shrink in length, the fade is very variable so it’s best to just make the 90’s too long if that’s where the kick will be, and to the right length to cut.

A kick 90

bend a kick 90 wilderness

finished kick 90. ​​The 90 degree bend is no longer in line with the rest of the conduit. wilderness

A double 45 degree 90

The final method for making a 90 degree is to make two 45 degrees instead. Sometimes there is an obstacle in the corner of two walls or a wall and a ceiling where a typical 90 has to pass. The answer here is to bend two 45 degree elbows with a short section of straight pipe between them. The total curvature is then 90 degrees, but the path that the pipe follows misses the actual corner of the wall.

To make the turn, measure the distance to the corner (not the obstacle). Decide how far back to offset the first bend so that the pipe misses the obstruction when bent 45 degrees. Just a little practice here and you’ll become quite proficient at making this call. Subtract this measurement from that to the wall, and then subtract 1 more inch. The extra inch is necessary because the line isn’t a thin pencil line, but a thick three-dimensional object that makes rounded bends instead of sharp corners.

Example: The distance to the wall is 50 inches, it has a 3 inch round pipe right in the corner and you feel like a 45 degree bend 6 inches from the wall will release the pipe. Mark the line at 43″ (50″ – 6″ – 1″). Now multiply the 6″ number by 1.4 (6″ x 1.4 = 8.4″ or about 8 3/8″) and make a second mark 8.4 inches past the first mark.

Use the notch indicating the center of a 45 degree bend to align with the first mark and make a 45 degree bend; Push the tube forward in the bender and repeat the process, making sure the tubing has not rotated in the bender. You now have a 90° turn that misses the corner obstacle.

Many electricians prefer to make these smaller bends “in the air” because it’s much easier to get the bend right. If you are unsure about this, you should read EMT Electrical Conduit Pipe Bending Instructions, which have a section on airborne bend offsets.

One final note: This article is just one of several written by an electrician for electricians. A comprehensive guide to bending wire has been written, including a brief description of each page, along with a link to each page, as well as a handful of other links to pages that electricians might find useful.

Feel free to search this front page for anything else that looks interesting. If you don’t find what you are looking for, leave a comment and it will be considered for future pages; The entire series is and remains a work in progress.

Bending a Double 45 Set up for the first 45 degree bend. 1/3

This article is accurate and truthful to the best of the author’s knowledge. The content is for informational or entertainment purposes only and is not a substitute for personal or professional advice on any business, financial, legal or technical matter.

Answer questions

Question: What is the maximum number of bends a conduit can have before you need to install a junction box?

Answer: There is no limit to bends, but the limit to bend degrees is 360 degrees. Four nineties, 36 ten degree arcs, 8 45 degree arcs; these are all at the limit.

© 2010 DanHarmon

Dan Harmon (author) of Boise, Idaho on March 18, 2020:

As explained, this is a function of the bender, not an automatic figure that’s good for everything. You’ll need to check your bender to find out. They vary.

John on March 18, 2020:

How much deductions for 2 inch and 4 inch.

Dan Harmon (author) of Boise, Idaho on June 21, 2019:

@Javier: You are allowed to bend 360 degrees before a J-box is required. There can be 4 or 10 bends, but the total bend cannot exceed 360.

mbrio on January 25, 2017:

Thanks man! I tried to do a double 45 and couldn’t get it to work. I knew I was doing something wrong but couldn’t figure it out. Thanks again!

Dan Harmon (author) of Boise, Idaho on August 16, 2016:

They are limited by code to 360 degrees between junction boxes. Distance doesn’t matter, just that there’s no more than 360 degrees before a second box is installed.

Mohsen on July 31, 2016:

Thank you for comprehensive descriptions

Is there a limit to the number of 90 degree or 45 degree bends in the EMT?

In other words, how many bends of 90.45 are allowed in 6 foot EMT?

Dan Harmon (author) of Boise, Idaho on April 01, 2016:

Yes, that works quite well. It’s only when you have to be with 1/8 inch or so that it starts to fail, and that’s rarely necessary. Maybe with a big rack of pipes, but how often do we put a Kick 90 in a rack? I did, but rarely.

Sparky2132 on 04/01/2016:

Whenever I kick a 90 I use the same multiplier I add at an offset. Say I need a 7″ kicked 90 which I multiply by 2″ (if using a 30° bend), mark the pipe at 14″ from the back of the 90 and then bend to a 30° boom. It works with all Degrees I tend to use 10° because it pushes the kick father out of the 90 and keeps the degrees down in the run.Just remember your visit had more than a 90 in it, check it’s plumb in all directions and is level. Get the Do it right and make it look good. Remember that bending tubing is an art form. There’s no better feeling when you’re done with your runs and people are taking pictures and over yours Work on the phone The best description I’ve heard of what has been said about my plumbing is “It looks like water is flowing!”

Dan Harmon (author) of Boise, Idaho on March 22, 2016:

Excuse me. I will rewrite this section. But short, with the 90 already bent, put the pipe bender in place and apply just enough pressure to tighten it onto the pipe, but not enough to bend the kick just yet. Measure how high it is from the ground. Add the amount of kick and bend to that height.

How tall the pipe is depends on the pipe diameter (if you measure up, and that’s easier than trying to read the tape at the bottom of the line), how long the kick is (how far the kick is from the 90 removed) and with the bender’s mark (usually how thick the bender’s metal is).

Thanks Carol for the tip that it was unclear.

Carol on March 22, 2016:

In your description of the Kick 90 you say to add 1.5 inches to the “first measurement” but I can’t find a description of measuring anywhere in the Kick 90. I would like to understand how to measure and mark for this.

Many Thanks

TruthisReal from New York on October 24, 2015:

Very cool hub and helpful! i follow you now

juliajohn24 on May 01, 2014:

You guys who are there are doing an excellent job.

Dan Harmon (author) of Boise, Idaho on July 11, 2012:

no A short radius, illegal now, but never a long radius.

Mark Ericksen on July 11, 2012:

Have you ever used the Ericksen long radius bender?

(T or F)

Radius adjustment is the distance between the center of the bend and the end of the bend and is used to move the bend away from the obstacle.

In today’s digital world, there is a smartphone application for everything. There are apps for connecting with friends, planning a trip, and even apps for grocery shopping. With all the apps out there, it’s no surprise that there are even apps to help electricians and plumbers with their projects. With so many apps to choose from, finding the ones that suit your electrical needs can be difficult and overwhelming. That’s why we made a list of some of the top apps.

iBend App – This app is perfect for electrical contractors who need to bend a large amount of pipe for projects. iBend ensures accurate tube bends by doing the math for you, saving you time. You can even customize the app to mimic the exact bender you use. The app is available for iPhones for $4.99 and for Android phones for $2.99.

App features:

Calculate pipe bend marks for an offset by entering height and bend angle.

Calculate pipe bend marks for a rolled offset by entering the slope and slope of your offset.

Calculate pipe bend marks for a three bend saddle by entering the saddle height and selecting the bend angles.

Calculate the adjustment for the starting point of an offset to make your offsets parallel.

Calculate pipe bend marks for a connection 90 to avoid a round, square or rectangular object in a corner.

Calculate tube bend marks for a segmented 90.

Calculate pipe bend marks for 90 stubs and up.

Possibility to edit the deductions/captures for pipes of different sizes.

ElectroDroid App – With this app, electricians have as many tools and references at their fingertips as possible. ElectroDroid comes in two different formats: a free version that has access to basic tools, and a paid version. The PRO version has no ads.

It also has some additional features (e.g. the “Inverse Resistor Calculator”, improved LED resistance calculator) and more pinouts and resources.

You also get additional free memory space in the circuit simulator Everycircuit. Both the free and paid versions of the app are available on iTunes and Google Play.

App has the following tools:

Resistor color code decoder (3–6 bands, with inverse search);

SMD resistor code;

Inductor Color Code Decoder;

Ohm’s Law Calculator;

reactance/resonance calculator;

Filter;

voltage divider;

resistance ratio, value/series/parallel;

Calculation of the capacitor charge;

Zener Diode Calculator;

LM317 Adjustable Voltage Regulator/Calculator (with adjustable values);

Fieldwire App: Fieldwire is a task management app designed specifically for construction workers and the construction industry. You can organize your tasks by blueprints, construction sites, and task categories for a simplified and more user-friendly organization system. You can set deadlines for tasks, and Fieldwire will send you reminders and let you know when tasks are overdue. The app comes in a free and paid version and can be downloaded to your iPhone or Android phone.

App has the following tools:

Create defect lists directly on your drawings and blueprints to put tasks in context.

Notify employees of assigned jobs via email or app message.

Instantly see which tasks are completed or overdue.

Quickly navigate through your to-do lists by location or priority.

Add details to your tasks by uploading photos, PDFs and other attachments

Add details to your tasks by uploading photos, PDFs and other attachments. Generate daily reports to highlight progress and any pending jobs.

Share up-to-date technical drawings with everyone who needs them.

BuilderTREND App: Has an in-app messaging tool that enables real-time communication between subcontractors, suppliers, product managers and customers. This will help minimize errors and communication gaps in a project. With BuilderTREND you can even complete payment transactions within the app. BuilderTREND starts at $99 per month and is available for iPhone and Android phones. This app seems to have limitless features to help you with any project from start to finish.

App has the following tools:

Send bid requests

update schedules

send orders

Customized login page

Customer reviews on your website

Impressive sales presentations

Customized login page

Customer reviews on your website

Customized login page

Customer reviews on your website

Many more features to list

Articles used:

https://www.tsheets.com/best-construction-apps/

Tags: Apps, Smartphone Application, Wheatland, Wheatland Electric, Wheatland Tube

The ____ engine types are generally the most rigged Squirrel Cage

GROUNDING: To be effective, a grounding system must limit the voltage in the electrical system and protect it from all of the following except ____ live

All exposed live parts operating at ______ or more between terminals must be protected. 50v

Motor circuits are covered in ______. Article 430 of the NEC

There are _______ NEMA-approved motor designs. 6

A _______ enclosure is completely closed. Explosion proof

The _______ stands for the stationary magnet of a DC motor. field poles

The _______ motor has low starting torque, low efficiency and noisy common pole

The minimum allowable diameter of galvanized tubing for a grounding electrode is _______. ¾”

A grounding clip is used for _______. Attach the grounding conductors of the devices to metal junction boxes

An acceptable group thing electrode is a _______. Metal frame of a building that is effectively grounded

Iron or steel plate electrodes must be at least _______ ¼” thick

If non-metallic housings are used with MN cables, which of the following statements is true? NO connection to the box is required

MN : Romex with non-metallic sheath

If the frequency of an AC circuit is 15 cysts per ¼ second, the Hertz rating of the circuit is _______. 15 cycles X

________ = ___ 60Hz

0.25 sec 1 sec

The sign of 0° is _______. 0

A transformer has primary 200 turns, secondary 150 turns and primary 1206 AC. The voltage on the secondary side is _______. 200 150

___ = ____ 90 volts

120X

200x150x120

____ = __________

200 200

X = 90V

The self-induced voltage at an inductance L is caused by a change in current compared to _______. time

The total capacitance of a 20 microfarad capacitor in parallel with a 10 microfarad capacitor is _______. CEQ = C1 + C2 = 20 + 10

In parallel with this, 30 microfarads

Engine: she + app

The output power of a motor is measured in? hp

AC

The average voltage reading on a circuit with a peak voltage of 170 V is _______. 108v

Springback is a term used to describe the _______. Tendency for the tube to relax to a bend angle slightly less than that indicated on the bender pointer when the bender is released

An engine’s FLA rating can be found on the _______. type label

The most common service factor that appears on an engine nameplate is _______. 1.15

The best application for a shaded pole motor is in small fans

Shaded pole motor – AC single phase

Induction Motor – Small squirrel cage motor where the AUX winding consists of a copper ring or bar surrounding part of each pole. The AUX winding with one turn is called the SHADOW COIL.

If the time for one cycle is 0.1 seconds, the frequency is 10

1

—= 10

.1

Meters used in AC circuits show the value _______. effective value

Root means square

A transformer with a primary winding of 400 turns and a secondary winding of 300 turns has _______. Reduction ratio of 4:3

The secondary of a current transformer under load should NOT be opened because of _______. Induced high voltage

If the area of ​​the plates of a capacitor is increased, the capacitance is _______. increase

pipe bending

The result of 2 tread bends in opposite directions in a conduit results in a _______. offset

If a job site has a cold water line, driven-in ground rod, and ground ring, _______ must be connected to the ground system. All of those

To prevent a one-shot bend shoe from digging in when bending rigid aluminum, you should _______. Coat the conduit with WD-40 or petroleum jelly

For a given number of poles, the _______ determine the speed of an AC motor Frequency

A transformer with 100 turns on the primary and 10 turns on the secondary is a _______ transformer. step down

In an inductive circuit, the current at 180° is _______. 0

Unless otherwise noted, calculations in the AC circuit use ______ RMS values

Root means square

Both induction and synchronous motors work on the principle of a rotating _______ field. Magnetic

The two dimensions an electrician needs to know when making a 90° stub bend are the desired pitch and the pickup spacing

A plate electrode must have AT LEAST _______ square feet of surface area exposed to surrounding soil 2 square feet

Portable mechanical tube bender can be used as a one-shot bender for _______ smaller tube sizes

If you make offset bends, the two treads must be made perfectly parallel or the resulting offset will have a _______. dog leg

In AC circuits containing only resistance…. All DC rules and laws apply, including Ohm’s law and Kirchhoff’s law

The permanent destruction of metal parts to form an electronically conductive path that ensures electrical continuity and the ability to safely conduct any current that is likely to be impressed is called? connection

In a transformer… Electromagnetic induction occurs

In an AC circuit containing only one resistor, _______ will flow if the resistance is 10 ohms and the voltage is 120V 12A

E volts

1= — Amps= ——-

R ohms

120v

——–=12A

10 ohms

When making bends on short lengths of pipe, the shoe can be prevented from sliding by _______. Screwing a coupling onto the line

When installing a grounding rod, the tip of the rod must be positioned _______ degrees. Flush with or below

Hydraulic bending machines can bend rigid tubing up to and including _______ in diameter. 6″

The two types of shoes used in hydraulic arches are the _______ shoes. Are shot and segment

A ground wire must be connected to the natural terminal bar _______ a main distribution board

The _______ method describes a ground test using a three-point ground resistance tester

What is NOT an advantage of an auto transfer? Be bigger and stronger

The NEC requires conductors connected to the top leg of a 4-wire delta system to be color coded with what color of insulation or tape? orange

Heat Tracing: Electrical tracing of pipelines is performed for all of the following reasons except…to eliminate standard thermal insulation

What type of heating cable cannot be cut and terminated on site? mineral insulated

Hospital anesthesia sites count as _______ sites ? Class 1 Division 1

In hazardous areas where metal tubing is required, connections must be made with at least _______ threads fully engaged. 5

_______ is approved for use in most Class 1 Division 1 locations. Rigid Met Conduit

A Class 1 Division 1 site is best described as an atmosphere that is normally _______ hazardous

The primary purpose of pipe run seals is ______. prevent the passage of gases, vapors or flames from one part of the system to another

The track type approved for use in most hazardous areas is? Rigid metal tube

The wire body type that provides a connection point for FOUR crossing wires is a _______ wire body X

The purpose of isolated conduct at career endpoints is to _______. Protect the ladder from damage

A _______ type cond case has a single lid opening to the right. LR

It may look like an L (user), but I’m RIGHT.

The primary purpose of an explosion proof flexible coupling is to connect _______. Engines to a career system

The abbreviation for an entry sheet is _______. SLB

A _______ square junction box must be used when a 6 inch cable and two 4 inch cables enter on one side and exit at a 90° angle on the other side. (conductor size is 4AWL or larger) 44″

6″×6=36+4″=40+4″=44

For a straight pull, the minimum length for a pull box with 2 (1″ pipes) and 1 (4″ pipe) on one wall and 2 (1″ pipes) and 1 (4″ pipe) on the opposite wall? 32″

4″ × 8 = 32″

Even polls = no larger than 8× largest

One type _______ conduit had a straight threaded boss at each end and another threaded boss perpendicular to those two. T

Fact or fiction:

Capacitors are covered in NEC Art 460 FACT

If the heater fails in an IEC bimetal fixed overload relay, _______ the entire overload relay must be replaced.

Motor control:

A relay labeled 3 PDT-SB relay _______. Has 3 NU and 3 NC contacts (normally closed).

fact or fiction

Transformers are covered in NEC Art 450 Fact

The minimum voltage required to keep a relay coil energized is referred to as the _______ voltage. seal (keep)

The NEC specifies that floors of transformer vaults that are in contact with earth must be made of _______. 4″ concrete

fact or fiction

Resistors and reactors are covered in NEC Art 470 Fact

Fusible Alloy Heater Assembly – consists of heater element and solder pot. The pot holds the ratchet. Motor overload wheel in on position. Excessive current flows through the heating element and melts the pot. Because the ratchet wheel runs freely in the weld pool. It triggers a set of NC contacts in the starter and stops the engine. *probably a picture on the test

overload contact •

What happens to the current in the same circuit when the voltage is stepped down in a transformer? It is amplified

V⬇️ A⬆️

Which of the following methods can be used to visually check for flux leakage? iron filling

A motor’s nameplate states that the motor has an ELC of 13 amps and a service factor of 1.15. The additional current this motor can safely handle with intermittent power demand is? 1.95A

DISTRIBUTION SYSTEM TRANSFORMER:

Which of the following statements best describes mutual induction? The condition in which two circuits share the power of one circuit

When sizing junction boxes, is the conductor equivalent of a cable clamp? 1

When sizing outlets, is the conductor equivalent of a switch? 2

When calculating outlet capacity, each duplex outlet counts as _______ conductors? 2

The minimum depth required by the NEC for a round box is? ½”

Which condulet type is not a tow point for condulets that require a 90° turn? drag C

What type of rolling transformer would you use to convert lower voltage than required in a 120/208V system? Buck and Boost Transformer

LADDER INSTALLATIONS:

If several conductors are pulled together, should they _______ be arranged on the fish tape? staggered

BOXES & EQUIPMENT:

Another name for a lead body? Condulet

What is the recommended abrasive cloth used to clean cables during a splice? 120 grit ALO

Right or wrong:

When installing most heating cables, avoid overlapping. TRUE

What is NOT a high voltage cable? category 5

High voltage cable hi-pot testers typically have a micrometer and range scale to allow measurements up to ___ MA at which level the circuit breaker trips or the reactor collapses. 5 MA

Acceptance tests are performed at _______ the original factory voltage. 80%

Retests are performed at _______ the original factor stress 60%

What best describes a high voltage degree? An insulator

The outer shield in a high voltage cable is best described as _______. Semiconductor layer under a metallic layer.

All of the following connectors can be used to splice high voltage cables except _______. Split bolt connector

A quick test that can be performed to determine if an installation is good is called a _______ test. Goes / doesn’t go

Of the Terminator classes listed, _______ is the only one that provides sealing against external elements. class 1

The robust outer sheath for mechanical protection of a cable is referred to as _______. Jacket

HIGH VOLTAGE TERMINATION:

If the original rubber insulation was ¼ inch thick on a straight splice, what minimum size should it be built to? ¾ inch

What is the classification and layout of all ground level areas up to 18 inches high in an airport hangar? Class 1 Division 2

The higher the letter or #, the less dangerous

For example…

Class 1 Div 1 > Class 2 Div 1

Group A

> Class 3 •

The most severe hazard class is… Class 1 Division 1

DANGEROUS LOCATIONS:

Definitions of hazardous locations

NEC Article 500 •

When the start and stop pushbuttons mounted in two or more control stations are connected to a motor control circuit, the start buttons must be connected to _______ and the stop buttons to _______. Home -> Parallel

stop -> series

The components used in hot water temperature maintenance systems are similar to those used in _______. pipe trace heating system

The requirements for the installation of electric underfloor heating/heating systems are defined in _______. NEC Article 424

The scanning method in which a target is detected when it passes between a photoelectric sensor and a reflector is called retro-reflective type

A vented service shaft in a commercial garage is a _______ location. Class 1 Division 2

Intrinsically safe devices are covered in NEC Article 504 •

A durable and effective seal is another method of preventing dust from entering enclosures through a Class 2, Division 2 conduit system? Horizontal runway at least 10 feet in length

What best describes the devices that help prevent the accumulation of moisture in the track system? Integral drains

The requirements for the installation of electrical trace heating on pipelines are defined in _______. NEC Article 427

The term used to describe starting and stopping an engine repeatedly at frequent intervals for short periods of time is _______. Jog

Heater cables installed in concrete for snow melting and anti-icing systems are typically _______ center-to-center. 12″

symbols

What type of wire is standard for low voltage milliamp signal systems? Single pair shielded

Several 12-year-old conductors are pulled together, how should they be arranged on a fish tape? staggered

The voltage drop of old. How does the current in a PVC pipe relate to that of identical conductors in a metal pipe? VD ⬇️ of alternating current

PVC > metal

More than

When transporting metal tubing, it is best to leave the thread protection caps on to avoid damaging the threads

Metal electrical conduit must be carried at what maximum distance from any junction or outlet box? 3ft

What does a wattmeter show? watts = power

The voltage of a DC circuit is to be measured. How to connect the voltmeter to ensure correct polarity? Negative meter terminal to reg or low voltage point in circuit. The positive connection of the meter to the positive or high potential point in the circuit.

What is the resistance of a 1250 watt, 240 volt resistive heater? (Image) 5.2 amps (response to test)

or

46 ohms or resistance

*it asks for resistance

What is the formula for calculating the total resistance in a series circuit of 3 resistors? R T = R 1 + R 2 + R 3

The minimum accepted DC megohm resistance of a 4160V motor is approximately 4.2 megohms

A voltage source in a circuit supplies 240 volts and draws 48 amps. How much resistance does the circuit have?

R = E = V = 240 volts = 5 ohms

__ __ __________

1A 48 amps 5 ohms

Use R = E

—

1

When three equal resistors are connected in parallel, the total resistance is… less than each individual resistor

All of the following are correct formulas for “Ohm’s Law”: (image)

Except…. E=P×I isn’t

(Picture)

what is tension electromotive force

what is tension electromotive force

What is the source voltage in a circuit that draws 1200 watts at a current of 5 amps? (image) 240 volts (image)

An analog voltmeter is connected to a 24V DC circuit polarity is reversed. Which reading will take place? O or less volts

What should be used when a cable tray system needs to be protected from sunlight? cable duct cover

A section of cable tray that makes two vertical 90° bends is known as… A vertical T (image)

Which of the following is intended for high voltage wire drawing? nylon