Wire gauge for electromagnet?

[BroncoDave]

HELL NO!!! We get Sparkletts delivered every 2 weeks at PG&E's expense. 6 - 5 gallon bottles and 6 cases of 12 oz. bottles and hot and cold water dispenser. The well is for the toilet, doing dishes, laundry, showers, watering the yard and garden and washing the car. Stuff like that.

 

[BroncoDave]

Got the pump up out of the well now and the MEGA-MAGNET ready to go down. Sending it down after a short break.

 

[4pyros]

Got the pump up out of the well now and the MEGA-MAGNET ready to go down. Sending it down after a short break.

Nice glad its working.

 

[BroncoDave]

Nice glad its working.

Not so fast there 4pyros, The first drop ended in disaster. The winch cable and the electrical wire got twisted together when it got near the bottom and got the 7" PVC protecting the magnet jammed up. It ook a bit to unjam it, but in the process the wires got yanked off the coil. Did I mention they were soldered to the coil? Got that all fixed then it wouldn't pick up but a couple pounds. Checked the batteries and the 12v oly had 5v. It's toast and wont hold a charge for more than 5 minutes. Taking another short break before I yank the battery out of my M/H.

 

[BroncoDave]

One more question. Is it voltage or amps that give the electromagnet it's strength?

 

[KeepItSimpleStupid]

You can't have one without the other, BUT if you wanted to control the magnets strength, you would regulate the current.

 

[MrAl]

Hi,

It's the current that causes the magnetic field and thus the force for picking things up, but every coil has resistance so it takes a certain voltage in order to achieve that required current to get that required force or holding strength. So a battery that is too low in voltage will not force enough current through the coil to produce enough force to pick heavy things up.

Holding force is always greater than regular attractive force, so if you can get the metal to contact the electromagnet it will be easier for the magnet to 'hold' it while you pick it up.

 

[BroncoDave]

Ok, here's what's happening. The mega-magnet is doing what it's suppose to do but seems kinda weak. I have 35v at the batteries and only 4v at the coil. That's a 31v loss in 200'. I'm using the wire that was used to run the pump (12 AWG). Any ideas?

 

[alec_t]

That gauge and length of wire should have <0.4Ω resistance. I'm surprised there's 31Volts drop across it. That implies a current of 77A ! Can you check that the connections either end of the wire aren't introducing unwanted resistance?

 

[MrAl]

Hi,

Break or partial break in the wire, or one of the connections is bad.

Inspect the wire carefully and all the connections. If the wire bends too easy in one place that probably means it is kinked and high resistance.

 

[ramuna]

Hi Bronco,
Given that the electromagnet route seems problematic to say the least, I'd like to suggest an alternative. Take a physically strong, non-magnetic container like an aluminium or plastic container (bucket, saucepan with side handles etc). Insert a strong permanent magnet into the container with its poles facing out through the base, and epoxy it into position. Tie a strong, eg nylon rope to the handle of the bucket (or handles of the saucepan) and lower that down the well. Let the rope take the strain. The same concept would also extend to the electromagnet, if you want to continue down that route.

For this, you would place the electromagnet AND battery into the bucket/saucepan. You would use a relay to switch current from the battery into the electromagnet, with a light-duty cable connected to the relay. this light-duty & low weight cable would be taped on to the rope. You would connect the free end of this cable to another battery or wall wart to energise the relay.

If the small standoff due the thickness of the base of the container causes unacceptable losses in magnetic lifting strength, consider cutting suitable holes into the base, to allow only the poles to protrude outwards.

You mentioned using a winch. If so, then you could replace the rope with a rope lifting harness. the harness would use the same knots tied to the same handle(s) as in the previous case, but would only extend a short distance above the container, ending in a loop. The winch hook would engage the loop, with suitable safeguards to prevent the hook slipping out inadvertently.

MrAl made a good point about non-magnetic scrap like lead. If that is a strong possibility, consider hiring a crane with mechanical grabber facilities, like this one in a scrapyard:

https://www.shutterstock.com/pic-37273147/stock-photo-mechanical-grabber-working-in-a-scrapyard.html

 

[tvtech]

^^^^

It's a wonderful uncomplicated World

Regards,
tvtech

 

[BroncoDave]

Hi Bronco,
Given that the electromagnet route seems problematic to say the least, I'd like to suggest an alternative. Take a physically strong, non-magnetic container like an aluminium or plastic container (bucket, saucepan with side handles etc). Insert a strong permanent magnet into the container with its poles facing out through the base, and epoxy it into position. Tie a strong, eg nylon rope to the handle of the bucket (or handles of the saucepan) and lower that down the well. Let the rope take the strain. The same concept would also extend to the electromagnet, if you want to continue down that route.

For this, you would place the electromagnet AND battery into the bucket/saucepan. You would use a relay to switch current from the battery into the electromagnet, with a light-duty cable connected to the relay. this light-duty & low weight cable would be taped on to the rope. You would connect the free end of this cable to another battery or wall wart to energise the relay.

If the small standoff due the thickness of the base of the container causes unacceptable losses in magnetic lifting strength, consider cutting suitable holes into the base, to allow only the poles to protrude outwards.

You mentioned using a winch. If so, then you could replace the rope with a rope lifting harness. the harness would use the same knots tied to the same handle(s) as in the previous case, but would only extend a short distance above the container, ending in a loop. The winch hook would engage the loop, with suitable safeguards to prevent the hook slipping out inadvertently.

MrAl made a good point about non-magnetic scrap like lead. If that is a strong possibility, consider hiring a crane with mechanical grabber facilities, like this one in a scrapyard:

https://www.shutterstock.com/pic-37273147/stock-photo-mechanical-grabber-working-in-a-scrapyard.html

Don't take this the wrong way. I really do appreciate all the help I can get with this, but I said it once and I will say it again. If one is going to comment on a post, please read and understand the entire post before commenting. The well casing is 8" in diameter and I am using 2 - 6v deep cycle RV batteries and 3 - 12v car batteries connected in series. See the problem with your suggestions? Thanks for your suggestions though. I do appreciate the effort.

^^^^

It's a wonderful uncomplicated World

Regards,
tvtech

"I WISH"

That gauge and length of wire should have <0.4Ω resistance. I'm surprised there's 31Volts drop across it. That implies a current of 77A ! Can you check that the connections either end of the wire aren't introducing unwanted resistance?

Something dawned on me about the massive voltage loss. Would I be getting a true reading at the coil? With it energized isn't the coil creating a dead short between pos. and neg? 0.4 is exactly what I got. All connections are soldered and good. The 200' wire is 3 stranded 12 AWG and I was using only 2 of the wires. Could the third wire be causing problems? I'm switching to 2 - 150' of 14 AWG solid wire.

 

[ramuna]

" The well casing is 8" in diameter"
Why not just re-bore the darned well ? The metal bits and pieces inside would be treated as rocks and would be drilled out just the same.

 

[tvtech]

^^^No mining machinery needed here.
Simple problem = simple but practical solution.

Regards,
tvtech

 

[BroncoDave]

^^^No mining machinery needed here.
Simple problem = simple but practical solution.

Regards,
tvtech

Except that the problem is NOT that simple. $30,000.00 to redrill and deepen the well. Pocket change. Why did I even bother trying this myself? Oh that's right, I'M A WORKING CLASS BUM THAT AINT GOT THAT KINDA $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

 

[4pyros]

Something dawned on me about the massive voltage loss. Would I be getting a true reading at the coil? With it energized isn't the coil creating a dead short between pos. and neg? 0.4 is exactly what I got. All connections are soldered and good. The 200' wire is 3 stranded 12 AWG and I was using only 2 of the wires. Could the third wire be causing problems? I'm switching to 2 - 150' of 14 AWG solid wire.

The resistance of the coil should be much higher than the power wires and there for will have most of the voltage across it.
Some how you messed up one or both of the power wires. You need to check them with an ohm meter. They should read as a dead short. 0 ohms.

 

[tvtech]

Except that the problem is NOT that simple. $30,000.00 to redrill and deepen the well. Pocket change. Why did I even bother trying this myself? Oh that's right, I'M A WORKING CLASS BUM THAT AINT GOT THAT KINDA $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

Now what??

Lost. Why you shouting at me ??

Things were going OK. Now this

Step away. Sit down. Go to bed. Sleep.
It will be OK Tomorrow.

No grudges held. You need no more than you had with the advise given here.
Your electromagnets were strong enough. Only a bit more patience.

 

[BroncoDave]

Now what??

Lost. Why you shouting at me ??

Not AT you tvtech, TO you about ramuna's post. Sorry, I thought you were being funny with the "No mining machinery needed here" comment. I was continuing the comedy with a little sarcasm.

 

[tvtech]

Not AT you tvtech, TO you about ramuna's post.

That's life..

Back to Basics.....it was working. Some people like to complicate things....and those are normally the ones that know SQUAT. And my post to/in relation to whoever he is ruma was meant to bring you back on track....not make fun of you. FOCUS.

Sleep on it. The Solution is at your fingertips without big costs that some like to project. Have I got your attention ??

And another Rep for you...why because I think you are frustrated beyond belief...

Keep it simple Buddy.

Regards,
tvtech