Building A Simple Motor Direction Tester

build motor direction tester

A simple motor directional tester.

Has this happened to you? Have you ever removed a motor from like a fan, waited a couple days, and then forgotten how to wire it so that it rotated properly, clockwise or counter clockwise? I have, plenty o’ times which is why I assembled this stupid and simple little tester for around $10.

Not much is more frustrating than installing a new motor into its frame, wiring it up, turning it on and then seeing it spin in the wrong direction. Because then you have to turn it off, disconnect the stubborn wires again, and remove it from the frame. And then reverse the procedure to re-assemble it. Fun times.

Here is what sometimes happens to me.

I will find a motor that needs to be replaced. Maybe because of the way it’s installed, or maybe because it’s cold out I don’t feel like making trips, for whatever reason, I remove the motor. Almost always I will crudely draw out the wiring diagram when removing it for ease of installation later. There are times when I forget to note which way it is wired to rotate, other times it takes so long to get parts by the time I do, I have forgotten.

The motor directional tester here is for 120V and below but you can make them rated for whatever you want as long as the components you use are rated for it, like 600V, etc.

Not only will this motor tester show you the direction you have it wired to spin, it can also show you if the motor is good or bad period. There should be a few pics to look at to help you along in building your own. It’s fairly convenient and it fits easily coiled up inside my tool box. Click ahead to check it out. Read more


what is electromagnetismSince for some reason I am still in an electrical mood today, let’s keep moving forward with the next step in our learning about motor theory. Yesterday, yes, yesterday, a post went up on the first step of this subject – magnets. Magnets set the foundation for how motors work, the why.

More of the why is coming in this post on electromagnetism. All of this is weird, science fiction stuff but it is also so awesome to know about. These magnetic lines and fields are flowing all around us, emanating from most things. Your phone being held up against your head, yikes.

Pieces of electrical equipment such as motors and generators, transformers and alternators, use magnetic electrical circuits in order to operate. Man somehow figured out that he can control this magnetism with his own hands, he can produce or control the magnetizing force.

We can produce a magnetizing force through an electrical current passing through a magnetic coil, like iron.

At the end, we should all be way more familiar with some basic principles of electromagnetism, how a magnetic field can be created using a coil of wire, and how to determine the direction of a magnetic field.

With that, we are off, rolling like a couple of freight trains. Click the button to keep reading. Read more

Magnets – Fields, Poles, Turning Motors

what is a magnetHave you ever looked at a piece of equipment and wondered how it was rotating? Such as, what is making that fan turn? Most likely a motor of some sort is making that equipment or machinery turn, somewhere. A motor could be connected directly, called a direct drive, to the machinery. Or, it can be connected with maybe a sheave and belt arrangement. Yeah?

But what makes those motors turn? This post is going to go over not how motors work, but actually, physically what makes them turn or rotate in the first place.

A motor turns basically because of magnets and fields, and the arrangement of poles, and this is what I’d like to go over. I’m thinking this post on magnets will make up like a larger piece of motor theory. So motor theory will be the large topic, and magnets will be a sub-topic. And magnets are the root of motor motion so is also where we should start.

Hopefully, when you are at the bottom of this page, you will know properties of magnets and also some magnetism principles.

If you were to stop and look around on a busy corner, and truly grasp what was in front of you, you’d see so many motors in action. From vehicles, to fans, the coffee grinder motor at Starbucks has a motor with magnets that must follow the same principles as every other. An infinite number of pieces of electrical equipment operate because of like the collection of these rules and laws – that could be called magnetism.

All motors and power generating “motors”, run on magnetism. You ready? Read more

Sheaves – What Are They, Calculating Sheave Pitch, & More


A common sheave.

There is a lot of confusion in our building engineering and facility maintenance worlds when it comes to sheaves. Today, we are going to:

  • Define sheaves and what they are.
  • Cover fixed and adjustable sheaves.
  • How to figure out motor sheave pitch diameter.
  • Common sheave materials.
  • Learn how you can change fan speed with a sheave.

Sheaves can be confusing because some terms, like pulleys, are interchanged kind of depending on where you work or what you do. You might get told to go order a sheave but your supervisor really means a pulley. Or you may get asked if you adjusted the sheaves. Well if it’s a fixed diameter sheave you can’t adjust it like you could a variable one.

For our purposes, sheaves are going to drive belts or v-belts. If it uses rope or cable, we’ll call that a pulley for now. That may or may not be correct technically but for us, in our industries, we generally call belt driven pulleys, sheaves. Okay? Read more

Welcome New Members Woo Hoo!

Yes indeed, everyone read that right. The site has had two new members join in the last couple of days which is awesome. There isn’t going to be much to this blog post, maybe a more personal, regular one rather than some type of training. I feel like I have been churning out some posts at a decent rate but today I don’t necessarily feel like thinking ha ha. Just feel like writing. Barely.

I know I will go over at least two items. I have come to a decision on the date for giving away the multimeter and then a quick plea for some help from you people, if you feel like it. Then maybe any other rant I may have at the end if I’m not tired of typing. How cool would it be to actually have one of those birds from The Flintstones that pecked stuff out as you talked?

Anyways, I’m sure a lot of you are curious as to when the meter will be given away. Soon grasshopper. Read more

Parallel Circuits Explained

what is a parallel circuitYes sir, taking another shot at keeping on with the basic electrical training. A few weeks ago we started this section with series circuits and I mentioned that we’d eventually put a post up about parallel circuits. This is it baby.

Hopefully when you get to the bottom of the page, you will be able to:

  • Recognize parallel circuits.
  • Be able to define what a parallel circuit is.
  • Be able to solve for values in parallel circuits.

There are advantages and disadvantages to both parallel circuits and series circuits. We are not going to get into that here but didn’t want you getting confused between the two already. At some point after this post, probably in another 2 months ha ha, we will go over the last type of circuit that I don’t really know about, a combination of the two, a series-parallel circuit.

Parallel circuits have unique characteristics. Because of them, parallel circuits are the most widely used type of circuit. Power distribution in large cities is sometimes accomplished through parallel circuits, where feeder lines that deliver the power are connected in parallel to each other. Read more

Firetube Boilers

what is a firetube boiler

Inside a firetube boiler.

What is a firetube boiler? What are the three main types of firetube boilers? Don’t know yet? No worries, we are going to cover it. You will most likely run into those two questions again if you plan on taking the boiler licensing exam, at least one of them, and it is usually the one about the three types of firetube boilers.

A couple weeks ago, a post went up that went over boiler classifications. High and low pressure steam boilers, the basic pressure requirements, and the type of fuel used all contribute to the boiler classification.

Another way to separate boilers is by the type of tubing inside or internal to the boiler. There are firetube and watertube boilers. Again, this post is going to focus only on firetube boilers. We will list quickly define the three types of firetube boilers, then get into the operation of one, such as, how they work or how they differ from watertube boilers. Or you could just wait another month until that post goes up and compare the two lol. Read more

Amprobe AM-510 Multimeter Review

amprobe am-510 multimeter review

Amprobe AM-510 – clean looking display and switch.

Glad you found your way to my Amprobe AM-510 Multimeter Review. The AM-510 multimeter is going to be the first tool given away in the tool drawing to a lucky winner. The drawing of course will be after the AM-510 review.

I have to say, based on the low price alone, I was skeptical of the quality. After getting it delivered and finally seeing it and holding it, my opinion has changed. The AM-510 meter seems rugged and accurate, enough for a homeowner as well as for someone in the engineering or construction fields.

So, keep on reading this Amprobe AM-510 multimeter review so you can decide for yourself if it would both meet your needs and stay in your price range. Read more

Converting a T-12 Light Fixture to T-8

difference between a t-12 and t-8 light bulb

Look at the size difference between the T-12 & T-8 bulbs. Sharpie for comparison.

This post is going to go over how to convert a T-12 fluorescent light fixture to T-8. As you may already know, T-12 fluorescent light bulbs are a thing of the past. It’s important that as either a building engineer or even a homeowner that you understand how to modify an existing light fixture.

Hopefully by the end of this pic heavy post you’ll know what you’re looking for when you open up a light fixture, then the steps to replace the ballast and bulbs, and then how to put it back together.

Every fluorescent light fixture is different and it would be impossible to have a separate article for each type. Use the engineering side of your brain if your fixture is different and make some tiny changes to the procedure.

As always, safety is the number one priority. You might open up the light fixture, see all the wires, and immediately think you’ve bitten off more than you can chew. Trust me, converting a light fixture from T-12 to T-8 is relatively simple. Think of it like a puzzle you have to solve.

If you do attempt to tackle this project, make sure all electricity to the light fixture is off. I’m sure I’ll mention it again as we go but your safety is completely dependent upon you.

The reason you might want to know how to convert a light fixture over from a T-12 type ballast and bulbs to the T-8 type is because T-12’s are being phased out and virtually outlawed. The T-12 bulbs consume more energy when illuminated, and also they are larger physically which means it takes more resources to make them AND then dispose of them.

Another bonus is that going from a T-12 size bulb to a T-8 size does not require you to change out the light sockets, or tombstones, as they’re known in the trade.

So, if you think this is a project you can do, and building engineers you should, keep reading to find out the basic steps for conversion. If I had to rate the difficulty of this project, I’d put it in the moderate category. You want to have at least a basic handle on electricity and wiring. Read more

Free Tool Drawing & Giveaway

tool raffleYep. You read that right. Free tool drawing and giveaway for all site members. Existing and new. You might be kind of confused, and just want to know how to enter so you could win a free tool. In a nutshell, you need to sign up. You must become a member (free) of That is it.

Quickly, here is how it will work (at first):

  1. Mr. Building Engineer Training (me) buys a tool or product to review.
  2. Tool or product gets delivered to me.
  3. I’ll review the item – open it, take pics, write about it.
  4. After a month or two, random numbers will be assigned to all members.
  5. A drawing will be held, whatever number comes up, gets the item.

Yes, This is a Bribe

Why am I bribing you?

Because I want members! I want people to read the content, engage with each other, the site, and me. It would be awesome if you guys thought of someone else like a friend or co-worker that could benefit from maybe winning the tool that we’re giving away and shared it.

Now, I’m not going to ask you to share it on Facebook or Twitter… okay that would be cool if you did too.

I would like to gain an audience that is into tools, repairs, maintenance just as much as me. We can talk about it, come up with topics together, and hopefully more. Read more

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