Electrical

As for Fukushima, I no longer recall what caused the cooling systems to fail, but it was not lack of diesel fuel, unless one thinks that the Japanese Government would have been unable to buy a tanker ship full of diesel fuel and station it on the wharf right in front of Fukushima.

Hmm. I'm thinking that tsunami seawater inundation destroyed the generators and electrical equipment, and maybe the cooling pump electric motors.

Joe Gwinn

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Yes, they failed not for shortage of fuel, but excess of seawater.

The original estimate of possible tsunami wave height was too low. “In Japan, they put up a heroic fight to get the electrical systems up and running again, but it wasn’t enough,”

The internet solved three way switches for me. The first time I saw a circuit diagram I understood it.

I never said two phases, because its not. I said split phase. You are literally half tapping one transformer. No different than multiple tap transformers for power supplies or commercial sound systems.

are

Are you saying all of that because you think I don't know it, or to help somebody else who might be reading it? I was taught basic res/com electrical at a young age by my dad. Before I learned refrigeration (also at a young age). Its kind of a requirement to know basic electrical before working on refrigeration equipment.

Now that's interesting. I have heard of farm shops with a residence and a shop on different services, but some farm shops also have three phase power. I've even seen well pumps on their own service, but two different service on a single residence is a new one on me. When I installed the sub panel on my shop I did install a meter, but its not a separate service. I just installed the meter so I could track power usage for tax purposes.

Ha Ha Ha... okay. Or I could use my circuit tracer. If its a panel I've worked in before most of the breakers are marked with a paint marker anyway.

I never said two phase, and I've never heard anybody call it that. Well nobody I consider knowledgeable. I said split phase. I do not know that is technically a correct term, but its fairly descriptive, and I have heard that term used before.

that term is

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Once I started I decided to cover the basics, not just respond to you specifically.

I've heard and seen the two lines called "phases" for lack of a better term.

"Adjacent breakers, such as 1 and 3, and 4 and 6, are on opposite “phases.” Breakers 1 and 6 derive power from L1, breakers 3 and

4, from L2."

GE doesn't make quad breakers unless they just started . You will need to get a 20 Amp DP thin breaker & 2 20 Amp SP breakers & put a single pole on each side of the DP breaker . Some GE panels don't have the buss bars for thin breakers . What you may want to think about is to put a sub panel where the car charger is & then pull the charger & the new circuits from the new sub panel .

animal

UNrer Rural Electrification in the early years that was STANDARD PRACTICE. When we bought out first family home in 1957 it had only one cieling light in each room - with pullchain switch - and one wall outlet in the kitchen with a 30 amp circuit. One 15 amp fuse for the kitchen and one for the lights. My father, having had worked as an elrctrician, made short work of that (and got his electricians jouirnyman's papers shortly after) He then did a LOT of rural electrification here in Ontario - but ty that thime a 60 amp 220 service was pretty much "base" and the 2 wire distribution system using earth return was pretty much eliminated except for a few private local power distributors. Ontario Hydro had almost totally taken over the grid

1955 in Perth County Ontario. I remember when we got our new electric clock because with the ols one "time really FLEW!!" New motor onthe washing machine and well pump too, and a new refrigerator. All the new stuff worked when we moved to St Jacobs. IOf I remember correctly the old clock had come with us from Elora when we moved in 1953-54 but it is possible we only had a windup clock there and in Conestoga before that.

another afvantage of 400hz for aircraft is higher RPM motors for running Gyro instruments without vacuum. Also easier to filter rectified DC in communication radios at higher frequency

Jim Wilkins snipped-for-privacy@gmail.com wrote: ...

...

On a constant-forward-speed bicycle, tire valves follow cycloidal paths. See first picture,

. For sine or cosine the wheel would need to be rotating in place.

Jim Wilkins snipped-for-privacy@gmail.com wrote: ...

...

On a constant-forward-speed bicycle, tire valves follow cycloidal paths. See first picture,

. For sine or cosine the wheel would need to be rotating in place.

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That's true if your frame of reference is standing on the street. If it's riding or repairing the bicycle my frame of reference applies. Since sine and cosine are tied together usually only the sine is used to adequately describe the waveform.

In digital radio the sine is the in-phase real component and the cosine the imaginary quadrature component of a complex number, imaginary meaning the dimension where the square root of -1 exists. Complex number math is a perfect fit for this and allows an equation to contain both without them interacting unless desired, such as to find the resultant angle. Here's a non-mathematical description:

The same analysis applies to brushless motors where the rotating magnetic field can be synthesized electronically from battery DC.

Airplanes used 400 Hz because 400 Hz transformers are a fraction the size and weight of that at 60 Hz.

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I was looking for why they settled on that particular number. A friend who worked in advanced aerospace at [...] researched aircraft 28V DC and found that it had been chosen due to a discredited idea about corona discharge leakage at the low pressure of high altitude. One source mentioned that iron losses increased rapidly as frequency rose above 400Hz. I tried higher frequency AC in a small Variac core to test it for a speaker crossover filter and found the losses quite high at 400Hz. It had clearly been value-engineered for 60Hz but not much higher.

"Boeing 787 and Airbus A380 These modern aircraft have opted to do without the alternator speed regulator required to keep the frequency stable. Therefore their frequencies extend from about 360 Hz to 800 Hz depending on the speed of the engines."

In digital radio the sine is the in-phase real component and the cosine the imaginary quadrature component of a complex number, imaginary meaning the dimension where the square root of -1 exists. Complex number math is a perfect fit for this and allows an equation to contain both without them interacting unless desired, such as to find the resultant angle. Here's a non-mathematical description:

The same analysis applies to brushless motors where the rotating magnetic field can be synthesized electronically from battery DC.

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A more practical application is calculating true, reactive and apparent power, where complex numbers combine everything into one expression.

[...]

Here's a better term to solve that lacking: "leg". "Split phase" is perfect for describing the service, but not so much for the conductors. I like "leg": "A service has 2 legs of AC, 180 degrees apart ..." or "In the panel, adjacent breakers are on different legs."

[...]

Here's a better term to solve that lacking: "leg". "Split phase" is perfect for describing the service, but not so much for the conductors. I like "leg": "A service has 2 legs of AC, 180 degrees apart ..." or "In the panel, adjacent breakers are on different legs."

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Thanks.

I suppose another sub panel is an option. I considered it. The main is just outside on the other side of the garage. I might pull a small sub off that instead.

Bob , that would be your best bet . Surface mount the sub & you will always be able to have access for adding new circuits when needed . I don't remember what all is in the main panel , since its such a short run maybe doing a 100 A feed to the sub should cover the next 20 years down the line as far as having available power . animal

Bob , that would be your best bet . Surface mount the sub & you will always be able to have access for adding new circuits when needed . I don't remember what all is in the main panel , since its such a short run maybe doing a 100 A feed to the sub should cover the next 20 years down the line as far as having available power . animal

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This has nice drawings of subpanel wiring:

BWHAHAHAHAHAHA... I ran a 100 amp sub to my "warehouse," thinking it would be all I would ever need. I was a contractor at the time. I just had a small office with an air conditioner, and a large warehouse with lights. That was it. Way freaking over kill. I thought maybe I might run my table saw or my welder once in a while, but not often. I had no clue I'd be running a real working machine shop on that sub panel years later. Now every time I get a few machines running I start doing math in my head? What has hard starting current for that machine? What has a tough cut that will amp up the load? (pun intended) If two or three machines hit a peak current at the same time as I am running this lathe will I trip the main? Some stuff I can control, but some I can't. The air conditioners trip on when they want to. Same with the air compressor. I may know in theory abotu what a hard roughing cut is going to be runnign on one of the CNC machines, but the reality even if I did I can't really plan around that. Okay, I have considered a soft start circuit for the air compressor, and all of my CNC mills soft start the spindles on VFDs, but its mental gymnastics some days.

I've never tripped the main for the shop, but I have tripped the main for the house before. What I really need to do is upgrade the service entrance for the house, but its about 450 feet of underground and a call to Blue Stake. The panel is the cheap part of that upgrade. Blue Stake is free, but cable and labor are expensive.