Sam Brown

[Sam Brown]

There’s a tricky little thing that you have to notice. The circuits for the RR, LR, and LF surface elements are all consolidated into one circuit on the schematic. In reality, they’re three different circuits, but since those circuits are all the exact same configuration, only a single circuit is shown.

This means that each of those three elements has its own L1 to H1 contacts, and its own black jumper wire that connects to its own hot indicator light.

Make sense?

[Sam Brown]

Hey, great job spotting the trick question! We were waiting for someone to do that. 50 bonus points for you! 😉

I do see how that wording is confusing, so we’ve gone ahead and tweaked it to say that you are specifically missing the diagnostic mode entry procedure, not necessarily the entire tech sheet.

Thanks for letting us know about this!

[Sam Brown]

Anytime. Don’t be afraid to post here in the forums whenever you get stuck! 🙂

[Sam Brown]

Yes, you’re right! Refrigerant does leave the compressor as a hot vapor. If you read through all of the possible answers to this question, I think you’ll see one that reflects this.

[Sam Brown]

Thanks for posting your question in the forum!

The information you need to answer question #6 is indeed in the course material. In fact, I believe it’s touched on at multiple points throughout the Basic Electricity module. Once place where the correct answer to this question very clearly stated is in the text of unit 3 of Basic Electricity. Review the material there, and you’ll find what you’re looking for.

And in the future, please don’t hesitate to post questions in the forum when you’re stuck! We’re always happy to point you in the right direction.

[Sam Brown]

Yes, exactly right! The reason that our LOI is the electrode is because, in this troubleshooting scenario, we hear a spark being generated, but it’s not coming out of the electrode like it should. As you troubleshoot further, you’ll figure out whether this is because the electrode itself is defective, or whether there’s some other, underlying cause.

Let me know if you have any more questions!

[Sam Brown]

Not quite — the spark lead shown on the schematic is just a connector between the spark module and the sparker wire.

Your LOI is supposed to be the “thing that’s not doing its thing”. There’s a specific component whose job it is to emit a spark into the gas, igniting it. If you’re still not sure what it’s called, I recommend you rewatch the video in Module 7, Unit 3 on spark ignition systems.

[Sam Brown]

There’s a specific part whose purpose is to deliver that spark to the burner. It’s at the end of the sparker wire that comes from the LF burner’s spark module. That’s the part that’s not doing its job, since it’s not igniting the gas that we smell coming out of the burner. Can you identify what that part is?

[Sam Brown]

You don’t need the wiring diagram at all to answer this question — in fact, it will tend to mess with you more than help. As usual, the schematic has all the answers you need.

Let’s do a thorough load analysis of one of the hot indicator lights. The schematic shows two different paths that Line 1 can take to get to the hot indicator light.

The first path is through contacts L1 to H1, and then through the black jumper wire. The jumper wires are hard to notice on the schematic, but they’re there — look for the label BK(J). When contacts L1 to H1 are first closed, thereby supplying voltage to the surface element, voltage is also supplied to the corresponding hot indicator light through the black jumper wire.

The second path for Line 1 is through the light’s bimetal switch. This is a switch that closes once the corresponding element gets hot enough. Once this bimetal has closed, the hot indicator light no longer needs L1 to H1 to be closed in order for it to stay lit, since it’s now receiving Line 1 through the bimetal. The bimetal will stay closed until the surface element has cooled down enough for the bimetal to open.

And of course, the hot indicator light is simply hard-wired to L2, so nothing tricky there.

Hopefully that load analysis helped clear up how the hot indicator light receives L1. To review: At first, the hot indicator light receives L1 through the same switch that supplies L1 to the surface element. But then, once the element has heated up enough, the hot indicator light also receives L1 through its corresponding bimetal switch. And thanks to this bimetal switch, the light can stay on even after the element has been switched off, at least until the element cools down.

If anything still doesn’t make sense, let me know.

[Sam Brown]

The answer is True. You will probably never be in a situation as a technician where you have to measure DC current. DC voltage you will absolutely measure many times. But not DC current. It’s simply not a diagnostically useful measurement.

[Sam Brown]

Great question! A couple of pointers I can give you to clear things up:

First, make sure you pay attention to the Samurai’s exact wording in that addendum video. He doesn’t say that the two ways of the drawing the circuit are perfectly equivalent. He just says that, as far as the power supply is concerned, the current draw is the same, and it changes in the same way if one of the loads were to go open.

You’re correct that point A and point B are not electrically equivalent. That’s because those lower three circuits are just an “exploded” version of the three parallel branches. To make A equivalent to B, you need to place A in the topmost parallel branch, at some point after the load. Where A is located currently is a point that doesn’t exist in the three exploded circuits.

If that still isn’t clear, let me know!

[Sam Brown]

Hey Kevin,

Thanks for your patience! After the discussion that Susan mentioned above, we’ve edited some of our wording in the course with reference to the Systems troubleshooting approach. You can see it for yourself in Module 2, Unit 1, but the 4 systems are called out like this:

1. The Refrigeration System: compressor, condenser, evaporator, refrigerant, associated tubing, and the condenser fan.
2. The Air Distribution System: evaporator fan, damper, door and door seal, and air return port.
3. The Temperature Control System: thermostat or, depending on the design, the thermistor and control board.
4. The Defrost System: defrost heater, defrost bimetal or thermal cutoff, evaporator thermistor (if used), and defrost drain system.

As you can see, the condenser fan is classified as part of what we call the Refrigeration System, which also includes the entire sealed system.

Now, getting back to the question that started this, we haven’t changed any of the wording on that, because it’s still correct. While the condenser fan is a part of the Refrigeration System, it is not part of the sealed system, since that refers exclusively to the compressor and all the sealed tubing that carries the refrigerant (both the condenser fan and the sealed system are part of the Refrigeration System, though).

Hope that clears things up! Let us know if you have any more questions.

[Sam Brown]

The condenser fan does play a key part in helping to cool off the refrigerant as it passes through the condenser coils, but it is not part of the sealed system itself. It’s part of the refrigerator’s air distribution system.

[Sam Brown]

Hey Kevin,

Think carefully about the wording of the question. “Two common sealed system problems encountered in the field are:”

So this isn’t a question about refrigerator problems generally, but specifically about sealed system problems. Your answer contained one item that’s a sealed system problem (weak compressor), but another that wasn’t (bad condenser fan motor). Look for the answer that contains only sealed system problems.

[Sam Brown]

Hey Kevin, thanks for posting your question in the forum!

The columns on that chart are grouped so that, for any particular temperature, the corresponding ohms and volts readings are to its right, not its left. With this in mind, take a look at the chart again and see if your findings correspond with the answer given.

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