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Susan Brown

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Viewing 15 posts - 1,096 through 1,110 (of 1,948 total)
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  • in reply to: question 7 final exam #19476
    Susan Brown
    Keymaster

      Sounds like you’ve got it.

      If 120vac is present at the load, this means there is no break on the L1 side of the load. Thus, the open is on the neutral side.

      If the fault were on the line side of the load, you would not measure any voltage at the load.

      Make sense?

      in reply to: question 7 final exam #19474
      Susan Brown
      Keymaster

        Yes, but if there’s an open on the L1 wire somewhere between the outlet and the load, how would that voltage be present at the load?

        in reply to: question 7 final exam #19472
        Susan Brown
        Keymaster

          I’m not sure what you mean about measuring 120vac “through” neutral. We measure it “with respect to” neutral. Meaning, one probe of your meter is at the terminal on one side of the bulb, and the other probe is on a known neutral point.

          On the other hand, when we place our probes on either side of the bulb, we get no voltage difference – they are at the same potential. Thus, we know that there’s no current flowing, and the bulb is just acting like a wire.

          If the open in a circuit is on the “hot” or “line” side of a load, where would you be getting the 120vac from?

          in reply to: question 7 final exam #19470
          Susan Brown
          Keymaster

            Correct – there is an open in the circuit.

            That’s part of the answer. The other part is which side of the circuit has the open.

            It’s a 120vac circuit, so line is on one side of the load, and neutral is on the other.

            We measured 120vac at one side of the bulb. What does this tell us about the location of the open – which side of the circuit is it on?

            in reply to: Basic Electricity Exam #19468
            Susan Brown
            Keymaster

              I’ve been replying to your reset requests, asking you to work with me on some of the questions you missed. I haven’t heard back from you. Have you received those emails from me? (if not, check your spam folder.)

              in reply to: question 7 final exam #19467
              Susan Brown
              Keymaster

                1. If current is flowing through the circuit, then why is the bulb not lit? Why is there no voltage drop across it?

                Remember: in a series circuit, current is either flowing or it’s not. It can’t flow in one part and not the other. It can’t flow at different rates within the circuit.

                Also, if current flows through a load, work will be done, and a voltage drop will be created.

                Does this change your mind about whether or not current is flowing in this circuit?

                in reply to: question 7 final exam #19464
                Susan Brown
                Keymaster

                  The bulb and receptacle are fine. We just want you to look at this electrically. Please answer the two questions above. I gave you those to show you how you should be thinking about this.

                  in reply to: question 7 final exam #19462
                  Susan Brown
                  Keymaster

                    Did you see my reply here? I was expecting to hear back from you, and work with you to make sure you understood the correct answer.

                    Susan Brown
                    Keymaster

                      Haha – it’s great to see someone using their brain on a Saturday night!

                      I’ll have to get Scott’s input on these… it’s been a crazy Monday… will get back to you!

                      in reply to: question 7 final exam #19454
                      Susan Brown
                      Keymaster

                        You’ve got a load (the bulb) that we tell you is “good”, yet is not lighting up. So, no work is being done.

                        1. What does that tell you about current flow in the circuit?

                        We also tell you that you do measure 120vac wrt N at one of the terminals. This is a 120vac circuit (L1 – N).

                        2. What does that tell you about the location of the fault – which side of the circuit?

                        These are the two questions you should be able to answer, if you think about the basics we’ve taught about current, voltage, and voltage drop.

                        in reply to: problem 8 on mid term #19449
                        Susan Brown
                        Keymaster

                          You got it, with one correction.

                          Voltage doesn’t “travel”, it is present, or felt. Current is what is moving in a circuit (electron flow). So, the electrons are shunted and do not travel through the main coil.

                          Voltage drop is created by current flowing through a load.

                          Note – I’ll have to hide parts of your answer so we don’t just give it away to others. The struggle with this question is a great learning experience!

                          in reply to: problem 8 on mid term #19447
                          Susan Brown
                          Keymaster

                            [answer hidden]
                            Bingo! That is the correct thinking.

                            What does this mean for the ignitor and booster?

                            in reply to: problem 8 on mid term #19443
                            Susan Brown
                            Keymaster

                              Hi Mike,

                              If I “Zen” the booster – I get L1 on my left and the main on my right.

                              On your right, as you are working your way to N, you have two options. Go through the main coil, or go through the closed detector switch.

                              Why did you choose going through the main coil?

                              in reply to: Having trouble with units of measurement #19440
                              Susan Brown
                              Keymaster

                                Hi Tim – where do you see that it is said that 4 mega watts is 400,000 watts?

                                Susan Brown
                                Keymaster

                                  Right now Scott is using this, which he got from Home Depot

                                  Klein Tools NCVT-4IR Voltage Tester, Non-Contact Volt Tester Pen with Infrared Thermometer for AC Voltage, IR Temperature, Great HVAC Tester

                                Viewing 15 posts - 1,096 through 1,110 (of 1,948 total)