Susan Brown

[Susan Brown]

We’re happy to help, but please answer the question I sent you via email first

[Susan Brown]

You should also watch this webinar at Appliantology:

https://appliantology.org/topic/72423-voltage-voltage-drop-loads-switches-jumpers-cheaters/

[Susan Brown]

An excerpt from Module 3, Unit 8:

Voltage is most simply described as the force that pushes electrons along in a circuit (the actual movement of those electrons being what we call current). Voltage is the prime mover or cause in a circuit. Everything else that happens in the circuit is an effect. When there is a difference in voltage between two points in a complete circuit, then electrons will move: they will be pushed away by the more negative voltage and be sucked in by the more positive voltage, a push-pull kind of a deal. The directed movement of electrons from that difference in voltage between two points is called current.

Voltage Drop, on the other hand, is an effect caused by electrons being forced through the resistance of a load by that voltage difference between two points.

This concept about Voltage Drop is key, so we’ll state it one more time: A Voltage Drop across a load is produced when current flows through that load.

When we talk about Voltage Drop, we’re always talking about a specific load that has current flowing thorough it. That’s why it makes no sense to talk about the Voltage Drop at a wall outlet that we’re checking with our meter, for example, because there’s no current flow and no load (the meter doesn’t count as a load– a good meter should never load the circuit enough to make a difference).

If you have an open anywhere in the circuit, this means current won’t be flowing and you won’t measure a voltage drop across any of the loads in that circuit. You may be able to do voltage measurements wrt N to determine if the open is on the Line side or Neutral.

[Susan Brown]

This is a switch, not a load. Loads do have line on one side and neutral on the other (assuming a 120vac power supply). That’s not the case for switches.

[Susan Brown]

The other two options are:

Defective water pressure switch
Someone removed the protective screen on the water inlet valve letting sediment into the valve

[Susan Brown]

Thanks for asking about this. We evaluated the question and answers and decided that it isn’t clear, so we added another bit of information to the question.

Here’s the question now. See if this helps you figure out the correct answer:

Question #6: You’re on a service call where the washer overfilled and flooded, and didn’t stop filling even when the customer unplugged the machine. What do you suspect?

[Susan Brown]

Ah – I just sent you an email before I saw this. You are now correct! I did reset you.

[Susan Brown]

Awesome – so glad to hear it!

[Susan Brown]

That’s correct!

[Susan Brown]

Which of the following is NOT one of the points made about voltage and current in the video for this lesson?

There is no absolute 120 volts out there somewhere
There is no absolute 10 amps out there somewhere
All voltage measurements must be made in comparison with some other point.
We arbitrarily designate the earth as having a charge of zero.
Voltage is a difference in charge between two points in an electric circuit.

[Susan Brown]

Good job!

[Susan Brown]

Here’s a hint: there are 4 correct answers to this question.

[Susan Brown]

No, it shouldn’t make a big difference at all. It is just in the section about electric dryers that we talk about L1-L2. Otherwise, all the information will be good for you.

[Susan Brown]

Hi Adrian,

Yes, this difference in power supply is the only significant difference you will find in the course due to the fact that you are in Europe and we are in North America.

In Europe, you don’t have the split-phase power like we do. Your Line – N is around 230vac, and as I understand it, all of your appliances and electrical devices run off of that.

Nearly all of our home appliances (and other electric items) run off of 120vac (Line – N).

The only appliances that run off of 240vac (L1-L2) in the US are electric dryers and electric ovens.

So even though our split-phase power is not directly relevant to where you live, it will benefit you to learn this, since it will deepen your understanding of electricity works.

[Susan Brown]

What do you want to mean with the expression “as far as the battery is concerned, the configuration are the same”?

I’m not sure where exactly we say this (if it’s in a video, it would be helpful to give me the time in the video where it is said), but it sounds like what we say when we are showing that schematic configurations can be drawn in different ways, but actually showing an identical configuration (which means, the way things are arranged or laid out). In other words, an electron would see them as being the same.

And another thing,the formulas from the ohm law’s are equals?Example from the Power formulas(P=ExI is not the same with P=IxIxR).

Yes, they are. For example, E=I x R. So, if you take P=I x E and then put “I x R” where the E is, you get P= I x I x R

Short and shunt

These are both based on the same fact: if an electron has two paths available to it, and one of them has zero resistance, but the other one has a load, it will take the path with zero resistance 100% of the time.

A short is a fault condition where something happens that causes a path for electrons to flow (a complete circuit) from the power supply to N (or ground) that does NOT have a load (resistance) on it. So, there’s nothing to slow down the flow of electrons. This will usually cause a blown fuse or some other failure.

A shunt is a deliberate circuit design that creates an alternate path for electrons to flow around a load, but there is still at least one other load present in the overall circuit, so you don’t get the fault described above. Usually the shunt is controlled by a switch.

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