allways use your tester

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billk554

Member
i recently answered a call on a 3 phase 480 volt battery charger. the charger was being replaced and the tech was shocked when he tried to do this. it turns out there were 3 chargers in a row and a 3/4 inch pipe feeding the three chargers. all of them wired with no. 12 wire and each were on their own 20 amp breaker. each charger was wired with the familair brown orange and yellow wires with a ground. what i found was during the installation one of the orange wires from lets say charger a was mistakenly pulled into charger b and the orange wire from charger b was in charger a. when the tech turned off the circuit breaker for charger a, all the indicator lights on the face of the charger went out and he thought everything was fine so while disconnecting the charger he found out differnt. now this is not going to be one of those posts where people should chime in and tell everyone about how many violations there are here. what this is intended to do is inspire all of us to use our testers before touching any wire. so when we see the flashing l.e.d. lights go out after turning off a circuit breaker we stll have to use our testers to make sure it is safe to work on. remember what happens when we assume somthing.:?
 

Buck Parrish

Senior Member
Location
NC & IN
That's what the Non Contact tester is for....beep beep beep beep beep beep beep beep , means you got power on some where or your backing up :happyno: It really is fast and easy.
 
Yes a NCVT is fast and easy, but it will also get you killed.
Only if you assume that no light means dead and don't test further. I always teach people that light means live, but that no light doesn't mean no live. Wave the stick around and if it lights up, find out why. When it stops lighting up, pull out the wiggy and verify. (It's like a lightbulb- if the bulb is on, you know it's working. If it looks off, you don't know why just by looking. Unless it's broken...)
 

jaylectricity

Senior Member
Location
Massachusetts
Occupation
licensed journeyman electrician
I'm pretty sure this is where "professional" is integrated into the equation, seriously, who turns off a breaker and does not further test the circuit?
Somebody with a troubled home life. Or any other number of things that could be on their mind. We like to think that you'd be stupid not to double-check, but we're human and it happens.
 

zog

Senior Member
Location
Charlotte, NC
That's what the Non Contact tester is for....beep beep beep beep beep beep beep beep , means you got power on some where or your backing up :happyno: It really is fast and easy.
Non contact testers do not work on DC, which is the output of a battery charger.

They also may not work of 3 phase AC where the conductors are close together, so you have to be careful about how and when you use non contact detectors.
 

jumper

Senior Member
Non contact testers do not work on DC, which is the output of a battery charger.

They also may not work of 3 phase AC where the conductors are close together, so you have to be careful about how and when you use non contact detectors.
Of course they may work when you do not want them to.:cool:

I still chuckle every time I think of you, a beeping NCVT, and the airport story.:lol:
 

texie

Senior Member
Location
Fort Collins, Colorado
Occupation
Electrician, Contractor, Inspector
I've run into "split" circuits like this. It's a real good wake up call to do proper checking before touching anything, especially at 480/277.
 

hillbilly1

Senior Member
Location
Atlanta,Ga
Occupation
Field coordinator/ technical support
Just wait until you find a disconnect with the hot and neutral swapped! 277 on the neutral bar with the neutral on the hot lug. Somewhere down the line they crossed up their phasing. Check everything!
 

Satchmo

New member
Location
Az
The tester you use can still get you killed. Remember LOTO too!

The tester you use can still get you killed. Remember LOTO too!

12 years ago or so Fluke recalled some testers that read 0 at 480 VAC. I am still never going to use a Wiggins solenoid tester again. At a mine they have a test point for the primaries which run at 12,470, It is used to check voltage so the mine can swap taps when the weather gets hot, and demand rises. So far I know of 3 people that have hooked class III testers to those test points. One melted a Fluke, another blew his Ideal into his face and chest and the third shot the solenoid into his face. The Fluke has a carbon fiber shell around that parts that explode when exposed to over voltage. I keep a non contact Fluke, and a few other Fluke testers around. The State of Arizona has an inspection staff of 2 and one half people for the whole state for mines. If an industry has an engineer on staff they need not have any NEC inspection or even follow the code. Another great Solenoid tester failure is industries that cater to military contracts and have high frequency power. The Wiiggy wont read at all, but you will darn sure get nailed. I feel investing $150-$500 for a decent Fluke true RMS and a non contact pointer pen is money well spent. Remember your "Lock Out Tag Out" or testing is useless! One idiot flipping breakers or disconnect switches and your day is ruined.

I never did meet the "half a person" mine inspector.
 
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