Electrical Safety

[chilly1]

Everyone needs to take a little refresher in electrical saftey.
1, don't touch unless you know
2, never work on "live" circuits
3, always disconnect the equipment before working on it
4, when working on a phase change rig that has capacitors treat the system as live even if it is disconnected from the supply as capacitors will store a charge for a long period of time
5, use a meter if you done have one get one
6, Pay attention you life depends upon it
7 always use a ground when running a compressor, compressors can short internally to groungd and without a ground path the electricity will use you or your computer to make the connection killing you and the computer...

[eagle101]

chilly1....very correct about electrical safety!
question chilly1.........
when a promi m1 is running and your just sitting there mousing around can the compressor blow up like a bomb or so shooting out parts threw the m1 case?????
thanks

[100]

( [thread title]
*safety )

Refreshingly important notice. Good post.

[kayl]

yes electricity can kill, even the electricians are dieing and they know what they are doing. if you eva receive an electrical shock you should see a doctor even if you feel ok as they check your heart rate to see if its ok.
when ppl are connection wires its best to solder them together or use screw terminals.
never just twist them together as they can come apart and cover them with electrical wire.

[JSU]

and cover them with electrical wire.

electrical tape , silicone inside the twisty connectors is also nice if its in a wet area/condensation around it.

[masterofpuppets]

Some good tips there chilly1. Electricity can KILL! I know someone who died from electrocution while working on a 30amp circuit.

[chilly1]

All it takes is 3 miliamp to stop your heart. You can get that from a 9V battery. A capacitor that is capable of dumping 10000A / sec
THE UNFORTUNATE PERSON WHO COMPLETES THE CIRCUIT WILL BE DEAD.
So dont ever play with capacitors, getting a shock is never funny it is always serious, watch your step around circuits and if you do recieve a shock and notice dry mouth,nerviosness, chestpain, lightheadness, blurred vision seek immediate medical attention, it is always a good idea to go to a medical facility after a shock. Shocks can kill hours even days after.

Short story.
I used to ride home from work with a neighbor. We were both electricians at a paper mill. He had gotten a shock off a 120V lighting circuit changing a light bulb. This was 10 AM he felt fine small shock not like it had never happened before a hundred times. He had a weird day he was thirsty and coldn't stop urinating. He thought it was due to the flu or something He went home, I rode with him he seemed normal. Dropped me off and I rode into work with my dad the next day. At the gate they told me he had died of heart failure, his heart had simply stopped, it seems that his potassium levels had dropped due to hids body's reaction to the shock, when he arrived home he took a shower laid on the livingroom couch to watch the news and expired quietly, his wife found him. He had passed when she was cooking dinner and had made not a sound.

Keep this in mind when you say I feel fine, Pay attention to yourself. Always seek medical attention after any electrical injury.

[masterofpuppets]

The only time I got a shock was when I changed a dead light without knowing the switch was on. Luckily I only got one spark from it and I was fine. Evil light bulbs!

[kayl]

anther thing for ppl to consider
check that you house has earth leakage protection circuit fitted, if not may consider working off a RCD box that plugs into the mains, (ie cutting say with a grinder and cut the electrical cord, mains trips and could save ya life)
and other tools when working with electricity.

[Revv23]

wow, im glad i read this, i had no idea tat a shock can kill after the fact, luckily only time ive ever gotten shockedwas when i stuck my finger in a light socket as a kid, and i work with open PSU's all the time.

Thanks for the heads up chilly, ill be passing this on to others.

[JohnFish]

All it takes is 3 miliamp to stop your heart. You can get that from a 9V battery. A capacitor that is capable of dumping 10000A / sec

Oh my god. 9v is nothing and still they can kill you. i remember being really young (~10 years old) and touching batteries (from small to 12v ones) to my tongue to check if they work. I never knew i suppose. Thats one of the most useful guides i have ever read and thank you chilly for reminding us

[Unknown_road]

only when you put a 9v battery to the sinus nerve in your heart will kill you. your body has a huge electrical resistance so only a few nanoamp/picoamp will cross your body. And moreover the most of the current will choose the fastest way across your body which is along the skin. and a battery is DC which is half as dangerous as AC. You should be very carefull with electricity but 9 volt is just not enough to make damage.
But I agree on the rest with you chilly.

capacitors charge up to the voltage you put on it. So if you put 120 volts on it and then onhook it, the voltage between the nodes is still 120 volts. people don't realize this and that is indeed very dangerous.

[Newb101]

Remember this kids... the one hand rule!

Keep one hand in your pocket while connecting or touching anything that carries electricity. Even if you are sure you disconnected it. Because if you happen to become the circuit through both your arms, you guessed it, it passes through your chest.

You can pretty much guess what happens next.

[Aphex_Tom_9]

Remember this kids... the one hand rule!

Keep one hand in your pocket while connecting or touching anything that carries electricity. Even if you are sure you disconnected it. Because if you happen to become the circuit through both your arms, you guessed it, it passes through your chest.

You can pretty much guess what happens next.

ooh boy...i came close to that once...open PSU + both hands
i was scared for like an hour after i felt the shock, im fine though (it was 2 weeks ago). That's some good advice.

[Scout255]

It's also recomended that you use only your right hand, as that way if you get electrocuted, the shock travels through your right arm and down your right leg into the ground. If it were your left hand it would go through your heart and then your left leg.

[FallenAngel]

I just told my wife to not let my kids play anymore with any kinds of battery, wow didn't know it too

[Unknown_road]

I just told my wife to not let my kids play anymore with any kinds of battery, wow didn't know it too

You let your kids play with batteries? Those things contain very harmfull chemicals.

[FallenAngel]

I never let them play with that, but you know how kids are, they found things we lost some months before, sometimes they pick the TV control and just take those batteries, if we don't see them they simply put in their mouth any kind of stuff, until we see them, kids don't know how dangerous life can be. It's why we are always near... btw my english sometimes sucks and now I see that phrase and noticed that someone could think I was a bad father letting my kids play with batt. I will rephrase it "I just told my wife to never let them play with any kind of battery" and I was refering to TV controls batterys anyway...

[Revv23]

i doubt a AAA battery will be a health risk, even to a small child.

[chilly1]

Remember 3 millaamps of current can stop your heart, how your body becomes conductive enough to conduct that current through you heart is what matters so it is best not to play around with electricity. Higher voltages need less resistance to move 3 ma so you guys in europe and 220V house current be careful......

[Unknown_road]

I study electrical engeneering and I daily have connectors in my hand with up to 30Volt DC and 15 VoltAC. It is even impossible to do my work without touching the bare connectors. A 1.5Volt battery is only a health risk because it contains dangerous chemicals. You should be very carefull nontheless but mainly you should know what your doing! Btw every shock is different, I survived many 230Volt shocks but some people die from much less.

[Pandrone]

I too have made the fault not disconnecting/discharging the capacitor in a rig. This capacitor was cracked open due to unknown reason. So you could se inside it, i didn't notice this and the compressor worked fine, so i was just about to cut the compressor out when i touched the capacitor, damn, it's not a nice feeling having that current passing through your arm...

I was lucky to just touch it with one hand, could have been much worse i belive.

[Adasi]

Higher voltages need less resistance to move 3 ma so you guys in europe and 220V house current be careful......

I really try to be careful, but you know - accidents are difficult to avoid. About a month ago my dad decided (don't know why) to change the switch which puts on the light in the bathroom and of course he didn't tell me. During the night I decided to go to the toilet and guess on happened... I put my hand on bare cables i got a shock of 230V (now in Poland we have 230, not 220). As a result i've fallen on my knees and couldn't stand up for few seconds, i was standing before of course
Thankfully nothing happend to me, I think that was the worst (longest) electric shock i've ever had.

So be careful guys

[hatemi]

Last night I was once again fidling with compressors and was filling the system with R290 and touched the service port when the damn thing was running...I felt like something hit me real bad and took 2 steps back. It took me quite some time to realize I had got an shock! The thing wasnt plugged to a properly grounded plug(well the plug is grounded but the damn extension cord wasnt) si I guess it was the reason but tonight I'm gonna take seome measurements with DMM and try to find out what realy was the reason.

You can be I was scared and my heart was beating like crazy!

[hatemi]

Well it seems it's running a 230v current between the ground and the blue wire...I have no idea of whats wrong with it but I'm pretty sure It shouldnt be like that. The compressor is Danfoss SC10D with start capasitor if that helps.

It seems to have some funky internal connections... Do you suppose I could still use it or do I have to just get rid of it?