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Question #2: Measuring DC current is a measurement you will probably never do as a professional appliantologist.
But based on what you said, if R1 is two times R2, and if R2 is 30, then R1 is 60. R1 + R2 has to be = 120. 60+30 = 90.
Hi Snoopy – that’s a bit more complicated than what we show in the Unit 3 “loose connection” video.
Micah – please watch that video and see if you can follow along the calculation, and let me know.
Hi Don,
I see that you sent in your application for the membership. That will get processed on our end and you’ll get notified by email.Which question is this for? I need to make sure I give you the right advice 🙂
Hi Micah,
In general, voltage is a difference in charge. Sometimes voltage is measured at some point with respect to neutral.
Voltage drop is specifically measuring voltage difference across a load. When current flows through a load (resistance), it creates a difference in voltage. That’s “voltage drop”.
So, the answer you chose for #1 is true about an electrical load. We were looking for something that is NOT true about a load.
For #7 and #8, we’ve got two loads (heating elements) in series. When current flows through them, they will generate heat. And you can calculate that heat using Ohm’s Law equations. Go back to Unit 3 and rewatch the video about the heat generated by the loose connection. It is a very similar scenario to this one.
Let me know how I can help you further!
So the voltage from N to G is 0.
Correct!
There are two types of AC circuits that we deal with in appliances:
L1-N, which are 120 vac circuits
L1-L2, which are 240 vac circuits.L2 is not neutral – it is another “hot” line.
#4 – sounds like you’ve got the correct answer now
#13 – answer is “a train on a track”Hi Joe,
Let’s start with your first question:
Question #2: An AC circuit is properly grounded and supplied with One Million Volts. You have your volt meter and measure the voltage from the neutral wire to ground. What do you see on your meter?Do you remember that we taught that voltage is not an absolute value of something that exists? Rather, it is always a difference between two points. That’s why when you measure voltage, you have to use two probes.
In this example, we’re saying that we have an L1-N circuit, where L1 is One Million Volts. You take your volt meter and put one probe on the neutral wire, and the other to ground. Is there a difference in voltage between Neutral and Ground?
March 11, 2020 at 4:01 pm in reply to: Does free membership at appliantology allow manual download? #18705Hi Don,
You have to be a Tech Member at Appliantology to download manuals.
https://appliantology.org/blogs/entry/1027-tech-memberships-at-appliantology/
Air distribution system and temperature sensing device
Wow – great job spotting that typo – thanks! We’re going to change that to “start and run winding” (start and main would also be correct, of course).
You’re welcome! Always glad to help.
March 10, 2020 at 1:49 pm in reply to: Module 1, Unit 7, Ref. Air Dist. Sys.: Evaporator Split or Approach #18693Thanks for the input!
The “split” terminology that Scott uses is what he learned in Refrigeration Engineering (something he studied and practiced once upon a time). There are often cases where different disciplines use terms in slightly different ways. As long as we have a functional understanding of the phenomenon being described, we’ll be fine.
Hi Joe,
You are correct on all 3 accounts.
There are two loads in the circuit – the light bulb and the heater.
When the switch is open, electrons only have one path to travel between L1 and N: through both loads. Thus, both the heater and the light bulb with do work.
When that switch is closed, it is a shunt. It might help to think of the term “bypass” instead of shunt. A shunt deliberately bypasses one or more loads in a circuit, but NOT all of them. In this circuit, the heater is bypassed when the switch is closed, but the bulb still gets current.
A circuit will never be designed with a short. A short is a result of some kind of failure or fault condition.
Does that help?
Hi Darren,
They are similar in the basic function – to prove that there is a flame/ignition source before opening the valve to let the gas in. But the designs are very different.
A standing pilot system is very old technology and you’ll rarely come across it anymore except in off-grid applications or very old homes. No electricity is required for these.
We cover the glow-bar ignition systems and valves in much more detail in the Oven & Range course, so you’ll learn even more there!
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