drcampbell
Senior Member
- Location
- The Motor City, Michigan USA
- Occupation
- Registered Professional Engineer
Rural shirt pocket rules
- Thread starter letgomywago
- Start date
drcampbell
Senior Member
- Location
- The Motor City, Michigan USA
- Occupation
- Registered Professional Engineer
There's nothing common about Ohm's Law. Nobody's born knowing it; it must be taught.
Dunning–Kruger effect - Wikipedia
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Thankfully so. A column is not a wall so the installation of receptacles should be a design issue not a code requirement.
ggunn
PE (Electrical), NABCEP certified
- Location
- Austin, TX, USA
- Occupation
- Consulting Electrical Engineer - Photovoltaic Systems
Of course. Ohm's Law is a mathematical construct, as are Volts, Amperes, and Ohms; no one knows them intuitively.
There's nothing common about Ohm's Law. Nobody's born knowing it; it must be taught.
Dunning–Kruger effect - Wikipedia
en.m.wikipedia.org
Ohm’s law should be common knowledge for a journeyman electrician. Maybe common sense was a poor choice of words on my part.
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
I have encountered the exact same thing. I had never understood the potential mechanism for how that would happen. I brought it up with my dad once after a project where the foreman insisted that I build a wood stand for storing fork lift batteries, siting this issue. My dad explained it to me.
WAY back in the 20s and 30s when he was growing up, car battery cases were made of hard natural rubber. If you set the battery on concrete for a length of time, condensation that formed on the battery as it heated and cooled would drip down to the concrete, then the caustic lime in the concrete would leach out and attack the rubber case, causing small cracks to form That then allowed the electrolyte to slowly leak out and evaporate, killing the battery. Of course battery cases are plastic now, so this has not been an issue for almost a century, but urban myths persist.
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
Oh wow, CONFIRMED!Here's an explanation of that myth
The Truth About Storing a Battery on a Concrete Floor - ODYSSEY Battery
Perhaps you have heard the misconception that you should never store a battery directly on concrete to avoid damaging it.www.odysseybattery.com
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
I still insist my kids put the boat batteries and wood boards for winter storage. Because it makes it easier for me to pick them up off the floor in the spring.
PaulMmn
Senior Member
- Location
- Union, KY, USA
- Occupation
- EIT - Engineer in Training, Lafayette College
You need to get the batteries with the built-in carrying strap!I still insist my kids put the boat batteries and wood boards for winter storage. Because it makes it easier for me to pick them up off the floor in the spring.
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
Or just make the kids pick them up for you. I tell my son all the time when I have him do something like that; "This is why I made you!".
sgtsparky
Member
- Location
- Dexter, Oregon, USA
I learned about the hard rubber in high school electronics, it’s amazing how that keeps going but internal resistance causes discharge and the old rubber increased the rateHere's an explanation of that myth
The Truth About Storing a Battery on a Concrete Floor - ODYSSEY Battery
Perhaps you have heard the misconception that you should never store a battery directly on concrete to avoid damaging it.www.odysseybattery.com
letgomywago
Senior Member
- Location
- Washington state and Oregon coast
- Occupation
- residential electrician
I think I shed my coat and hat and belt always on a bed. The rest goes in the hamperFor many years I was involved in community theatre. To this day I will never toss a hat onto a bed or utter the word "MacBeth" in a theater building.
drcampbell
Senior Member
- Location
- The Motor City, Michigan USA
- Occupation
- Registered Professional Engineer
I expect Ohm’s law to be common knowledge for everybody who uses electricity.
My expectations have often been deemed unrealistic.
drcampbell
Senior Member
- Location
- The Motor City, Michigan USA
- Occupation
- Registered Professional Engineer
... and separators were made of wood.
My experience as well.
hmel577
Member
- Location
- Houston TX
Many years ago I had an inspector turn me down for aluminum wire, which was illegal in his jurisdiction. I had to teach him that A in AWG did not stand for aluminum. Funniest part is that the wire he was referring to was a factory tinned wire in a motor starter that came with it!
kwired
Electron manager
- Location
- NE Nebraska
Ohm's law is one the first rules taught in basic electricity courses that involves any relationship between voltage and current and should be something any electrical professional would know though.There's nothing common about Ohm's Law. Nobody's born knowing it; it must be taught.
Dunning–Kruger effect - Wikipedia
ggunn
PE (Electrical), NABCEP certified
- Location
- Austin, TX, USA
- Occupation
- Consulting Electrical Engineer - Photovoltaic Systems
Ohm's Law is taught literally on the first day of class in Circuits 101.
kwired
Electron manager
- Location
- NE Nebraska
Maybe even before introductions between student and instructor
Some of the boat batteries that I had to help with at my uncles boat engine shop were a 2 person or mechanically assisted lift. They had to handle a few real monsters. On that sort of battery some manufacturers will not provide lifting handles but their use instructions would suggest the pre-installation of plastic covered metal lifting straps. I had been in the Sea Explorer program of the Boy Scouts and learned how cargo was handled in loading and unloading on ships with their own 2 boom derricks. I rigged up an imitation of that mechanism and changed the batteries out on a cradled 74 foot topsail ketch by myself. My uncle said "Nice job Tommy but don't ever do it again. If one of those batteries had gotten away from you the repairs to the deck would have cost me a fortune." I just hated the task of building a plank road for the fork lift to be able to reach the boats that were sitting in cradles with soft sand around them.
Tom Horne