Susan Brown

[Susan Brown]

Hi Robert,

The clue is in the word “total”. What does that make you think of doing, mathematically?

Here’s one place where we show finding and using total resistance of two loads in series: the last video in Unit 3, starting around the 4 1/2 minute mark.

https://my.mastersamuraitech.com/module-3/basic-electricity-ohms-law/

We also mention total resistance of loads in series in the 3rd video in Unit 5: https://my.mastersamuraitech.com/module-3/basic-electricity-series-and-parallel-circuits/

Do you see how to do it?

[Susan Brown]

Always glad to help!

[Susan Brown]

Correct.

Do you have a way to print out the schematic? I would like to see you trace out how L1 can get to the LF hot indicator light.

[Susan Brown]

Hi Tim,

It seems like you are looking at the wiring diagram, which is much more difficult to figure out. If you are looking at the “Hot Ind Lights” on the schematic diagram, it’s pretty simple to see the two wire colors coming in to the LF one. Let me know if that help you.

[Susan Brown]

Well, yellow obviously is – you identified that as the wire on one side of the indicator light. We want to know the color of the wire that’s on the other side of the light. You just have to trace it towards the power supply to see its color.

[Susan Brown]

One more question: if you have L1 on one side of an element, and current is flowing, can you still have L1 on the other side?

[Susan Brown]

Does the explanation above not make sense in some way? We are pretty much spelling the answer out for you there.

Are you being thrown by the way the jumper wire is drawn? The whole wire is not shown on the schematic – just each end, where it ties into the other circuits. I’m trying to figure out how you think L1 could travel through a surface element on its way to the LF hot indicator light.

[Susan Brown]

It’s not an inconvenience at all! It’s all part of the training to help you out here 🙂

[Susan Brown]

Correct, so the black jumper wire branches off of the wire that goes to the hot indicator light.

The question you were not sure of asked for the color of wires that supply power to the LF hot indicator light. You seem to be looking at the correct load – that little light symbol on the wire labeled LF-Y. Do you still have some difficulty in answering the question?

[Susan Brown]

Yes!

Here’s the explanation that we gave on the quiz results – had you seen this?

“When the surface element is first switched on, the light gets L1 through the L1 to H1 contacts of the infinite switch and the black jumper wire. This can be easy to miss because the two ends of the black jumper aren’t explicitly shown as being connected.

During the element’s operation, once it gets hot enough, the light’s bimetal switch closes, providing another path for L1. This means that even after the infinite switch is opened, turning the element off, the light stays lit until the element cools off enough for the light’s bimetal to open again.”

[Susan Brown]

Here’s what you wrote in email:

I am looking at the schematic diagram. The light appears to be labeled LF-Y. So following L1 it seems like it would go through an infinite switch (H1) and through a jumper.

I’m glad to see you are on the right track! Correct.

But further down that wire H1 is on there is the Surface Element and then a switch labeled protector, next to that i see BR or Y making me think the protector bi-metal (if that’s what it is and I am not mistaken) making that another way of travel.

The Surface Element is a load in that circuit. Will the wire to the right of it be L1 or L2 (if the switches are closed and current is flowing)?

I was also wondering though that the wire that goes straight down from L1 and then third wire down goes right to the hot light switches, what is it for or what does it indicate? At first i thought that was an indicator that L1 was hot wired into L1 but did not end up being the case.

(I’m assuming you meant to say that the light was hot wired into L1.)

If something is “hot wired” to L1 or L2, that means there’s a direct line to the power supply with no switches or loads in the path. That’s obviously not the case here.

Do you know what this symbol is?

[Susan Brown]

Yes it does! It’s amazing how our eyes and brains conspire against us sometimes.

[Susan Brown]

Hi Paul,

American circuits will be L1-N or L1-L2.

What do electric ovens and dryers need?

And, what is the notation for the circuit shown in Question 6?

(Review Unit 6 re: household power supply)

[Susan Brown]

You’re welcome. And glad to hear it! That’s what we’re trying to do with the Midterm 🙂

[Susan Brown]

Exactly. The circuit current is the same throughout a series circuit, and will be determined by the total resistance in the circuit.

The current flowing through each load will produce a voltage drop in proportion to the resistance of the load, with all of the voltage drops adding up to equal the source voltage.

(Note: I will hide part of your answer so we aren’t just giving it away to other students!)

[Author]

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