Sam Brown

[Sam Brown]

I’ll go through your list one at a time.

1. We don’t recommend any specific impact socket set. They’re basically all created equal, and you probably won’t be using them all that much anyway.

2. Same idea with the drill bit set. No need to seek out a particular brand — just find a set that works for you. We tend to like bits that have hex bases, so they can easily be slid on and off of the drill as needed.

3. The 116 and 117 meters are both great, and as you noted, the only difference between them is that the 116 has the thermocouples. If you already have a good temperature meter, then go for the 117. If not, then go ahead and spring for the 116.

4. We use a Klein infrared temperature reader — bought it at Home Depot, actually. But again, there’s no need to go for a specific brand. Just find one that seems reliable and has the features you want.

[Sam Brown]

Hi Darren,

Looks like the Samurai just misspoke around 13:28. He meant to say that AC asynchronous motors are designed to slip and make horrible timers. Just a little slip of the tongue (pun intended). Good noticing!

[Sam Brown]

Could you give the timestamp of the portion of the video that you’re referring to?

[Sam Brown]

I’m assuming that you’re talking about the ignitor in a dryer, since you posted in the Washer and Dryer forum. If that’s not the case, let me know.

You said:

As the ignitor ages, it weakens and, it’s resistance starts to decrease.

Actually, the opposite is true. The resistance of the ignitor increases as it ages. Once the resistance gets high enough, the ignitor will not get hot enough to satisfy the flame detector, and the gas valve will not allow gas to enter the burner.

Flame rectification has no bearing when you’re talking about ignition in dryers. That only occurs in direct spark reignition systems, such as what you find in some cooktops.

[Sam Brown]

Yep, that definitely sounds like how that cycle was designed to run. The engineers would have done lots of testing and specified the components (such as the operating thermostat) to allow the cycle to complete roughly around the time when the clothes are dry.

[Sam Brown]

Without being able to look at the start device myself (beyond the picture at Amazon), it’s hard to say for sure. I do see a label that says “CAP” by the two terminals I think you’re talking about. That would indicate to me that those terminals are for connecting a capacitor. But again, without knowing more, I can’t say for sure.

[Sam Brown]

Multi-point ignition means that you have one spark module which sends sparks to multiple burners. Single-point ignition means that you have one spark module per burner. So the easy way to tell if you have single or multi-point ignition is simply by looking at the number of spark modules shown on the schematic.

Is there a particular schematic that you’re confused about? If so, let me know which unit it’s in.

[Sam Brown]

The purpose of an impact driver is to remove fasteners that are stuck or otherwise difficult to make turn. For example, they’re often used on washers to remove the main drive or bearing nut.

[Sam Brown]

If the conductor isn’t copper, then it would be aluminum. But I highly doubt that it is. Much more likely that it’s copper that’s tinted silver — manufacturers do that sometimes. The way to tell is to cut the wire and look at the cross section. If it’s copper, you’ll see that the silvery color is only on the surface.

If it really were aluminum, then yes, you would need special materials to make the splice, since copper and aluminum corrode each other. They make a special goop for aluminum to copper splices to prevent this.

It sounds like you’re using a voltage light stick or something similar to find the break in the cord. That’s going to be very difficult to do, since those devices aren’t designed for precise measurements. It sounds like you’re already getting false readings — you should not be picking up voltage anywhere on the neutral side. The sensor is probably just picking up the field from the voltage on the line side of the power cord.

To find the break, you’ll want to do an ohms/continuity test with you meter. You’ll want to open up the iron to do this so that you can get to the terminal where the power cord connects to the rest of the device.

[Sam Brown]

Great question! From a technical perspective, a capacitor in a circuit is an open. And in a DC circuit, this is always true in the practical sense as well.

In an AC circuit, things get a little more complicated. Because polarity is constantly reversing, you can still have current flow in a circuit with a capacitor. However, the capacitor must be rated for the frequency of the voltage in the circuit. Otherwise, there still won’t be any current flow.

In summary: current can never flow in a DC circuit with a capacitor. In an AC circuit, current can flow if the capacitor is sized for the frequency of the voltage in that circuit.

[Sam Brown]

Every voltage measurement just boils down to the meter detecting the difference in electrical potential between your two probes. We quantify electrical potential as volts.

Line should have a potential of 120 VAC when compared to neutral, and neutral should have a potential of 0 VAC when compared to line. That 120 volt difference between the two is what your meter picks up.

So if you want to confirm that you have a good neutral, you have to check if that neutral really has 0 volts with respect to line. The way you check for this, of course, is to simply put one probe on line, the other on neutral, and then see if your meter detects a 120 VAC difference between the two points.

Doing this kind of measurement is very common — it’s not peculiar to this particular diagram.

Is that any clearer?

[Sam Brown]

Don’t worry, we’re not in the business of shooting our students! As for your question:

At minute 13:44, Scott said that if we get 120v between Connect 5- Pin2 and COnnector 7-pin3. Can you explain why it was good to measure 120v? I thought getting 120v there means there is an open, and getting 0v means there’s continuity?

Whenever you make a measurement, you always have to keep in mind exactly what you’re measuring for. What you’re thinking of is measuring across a switch — in other words, putting one lead on one side of the switch and the other lead on the other side. If that were the case here, then you’re correct that 120 VAC would mean open and 0 VAC would mean closed.

What we’re doing with the measurement at 13:44 is not reading across a switch. Rather, we are checking for the presence of a good neutral at connector 7, pin 3, with respect to a known good line at connector 5, pin 2. In this case, a reading of 120 VAC indicates that you do indeed have a good neutral, since that’s the expected difference in electrical potential between a good line and a good neutral.

Make sense?

[Sam Brown]

In the video it says its an unintentional electric path between a power source and a grounded surface

That’s one definition of a ground fault. Another definition is when there is less current on Neutral than there is on Line. If you think about it, this is just a follow-on effect of current flowing to ground — if you have some of your current flowing into ground, then you’ll have less current flowing through Neutral. And the current on Line will be the sum of the current flowing through both Neutral and ground.

This current imbalance between Line and Neutral is a ground fault, and it’s what a GFCI device detects.

[Sam Brown]

Hi Shawn,

Sorry that didn’t get back to you — you’re right, the error that the Sperry is showing is undocumented. I can’t find anything on what three lights means. Either the Sperry has gone whacky or something is seriously messed up about that outlet.

Speaking of which, your readings with your meter don’t make much sense either. Were you using the LoZ function, or just the normal VAC function?

[Sam Brown]

Refrigerator and AC sealed systems work in fundamentally the same way, but there are some key differences. A big one is that refrigerators have defrost heaters, whereas AC units usually do not — there’s no need for them to have them, since their saturation temperatures aren’t low enough to cause frost accumulation.

The failure you’re describing (frost buildup on the evaporator coil when there is a lack of airflow) does happen in refrigerators too. However, it’s usually less noticeable because the defrost system mitigates it.

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