Avoiding Electrical Spark/Shock

[sonicj]

Originally Posted by OLD MEC

SONICJ Are nitrile gloves latex as I cant have anything latex near my skin and where are they available? I would like the better feel of surgical type gloves BUT??

OLD MEC,
they are a synthetic latex, so you should be good to go. imo, nitrile is FAR superior to latex surgical gloves for our use. they are more chemical resistant, normally much thicker, slide on easily w/o powder, conform very accurately to your hand once you get a little sweat going, latex free, textured grip, etc.

the ones i get are from sam's and come 200 to a box. (around $10 i think) being exam gloves, they are a little thinner than i would like for utility use, but are much thicker than some of the others i've tried. i also like the purple ones from Kimberly Clark. they seem to be a bit more tear resistant, but are a little more expensive. make sure you get the right size! they need to fit snug to tight.

once you start using them, you'll be hooked!
-sj

*edit* extra thick re-usable nitrile gloves are also available

[ComfortablyNumb]

All of this discussion about "exam" gloves, old fenders, stubby tools, etc. fills me with even more anticipation. Something like the thoughts that go thru your mind right before you are about to be violated by your internist. I'm sweating again!!

Seriously, everything went well for me today. I had to change the main positive cable, and actually relaxed after everything was disconnected as recommended. I still have a distant memory from several years ago of cutting a gash in the frame by creating a short with a small wrench somewhere near the solenoid. So all of this leaves me with a question. Aside from welding, gashing, exploding batteries, etc., can you actually receive an electrical shock while working on these carts? You guys seem to have it covered Thanks!!

[sonicj]

glad to hear you survived!

can you receive a shock? yes. can you receive a lethal shock? yes. is it likely that a shock at 48v will kill you? no. the reason being is that the resistance of human skin is pretty high and the voltage isn't sufficient to break down the dielectric effect of your skin.

i think they say it takes about 20mA of current to stop your heart. if i touch the probes of my multimeter, i measure anywhere from 1MΩ to 10MΩ of resistance. 60V across 1MΩ equals 0.00006 Amps. well below lethal! if i wet my fingers then grab my probes, i measure roughly 150KΩ. 60V ÷ 150,000Ω = 0.0004A. still below what is considered sufficiently lethal. with a typical hot off the charger 48V battery pack measuring at 60V, it would take a resistance of 3KΩ to pass a lethal 20mA. a metal wrench in one hand, a gold ring on the other, all coupled with sweat from working and that 3KΩ number could become a possibility!

a good habit to get into when working around dangerous levels of electricity (ie: golf cart) is to put one hand in your pocket when probing or making/breaking connections. this keeps the possibility of current flowing through your arms and across your heart at a minimum.

imo, you are much more likely to get hurt from burns as a result of shorting a tool or wire than electric shock while working on a cart.
-sj

[OLD MEC]

One word of warning when messing around near batterys, ( "NO PACEMAKERS" ) as Death can be in seconds? Lost friend last year from 48 volt shock to pacemaker? I dont know if it stops or runs away or delivers start up shock or what as I have heard all those ways?

[ComfortablyNumb]

Very interesting. I had always assumed that you couldn't receive an electrical shock from DC. Most folks ignore the possibility especially when working around automobile batteries (engine shut off of course), lawn equipment, tractors, etc. I've been severely shocked while accidently touching a spark plug or wire with the motor running, but never thought you could be shocked by a DC battery pack (unplugged from the charger). Could you elaborate a little more on this. Please assume that the charger is disconnected from the cart, and that the main + and main - are also removed and secured away from their respective batteries. I appreciate your insight.

[OLD MEC]

Many years ago I worked with a master mechanic that would test spark plugs and for weak cylinders by touching one finger to metal and the other to spark plug wire end on one hand? This was the same man that warned me of any battery or combination of batterys above 8-12 volts could kill you? ( this was mid 1940's when auto's used 6 to 8 volt batterys ) Not being an electrical engineer or a smart person I can only say from experience that touching even one 12 volt battery can give you a real bad shock depending on where it grounds out from your body. I can just imagine what a 72 up pack could do????
Most problems are caused by BURNS rather than shorts.

[shadowman]

well i have never been shocked but i have caught one on fire by dropping a wrench on the pack.............you should have seen it..........OHHHH PRETTY COLORS but the smoke tasted like crap........................

[ComfortablyNumb]

Well this settles it for me:
http://answers.yahoo.com/question/in...3113917AA9coie

I am way too uninformed and inexperienced to be working under the seat of my golf cart. I'll be 63 years old next week and have a master's degree in a field of science, but knew nothing about these DC risks. This idiot may need to get a Gator........

[shadowman]

no don,t back down.......as stated as long as you disconnect the main pos and neg cables from pack your pretty much safe........i mean accidents do happen so what happens if you get a gator and it bites you..............don,t let the cart scare you just practice safety and take your time when working on it lastly buy yourself the service manual...........................

[OLD MEC]

COMFORTABLYNUMB you are just a kid with lots to learn before you get old. For my last job before being forced to retire I had to learn basic electronics to design a automated heating-colling system for a city hall and public libray? Having been a auto-truck mechanic for over 45 years since age 14, and not having finished school that was a real reach. This caused me to be exposed to voltages up to 480 with transmission cables as big as your wrist?
The previous advise and what you posted shows ( confirmed what I had learned the hard way ) that in most cases you will be perfectly safe. If you take the time to protect yourself you wont have any problems with 48 volts.
Heck I didnt learn about computers until I was older than you and am still learning at 78.