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Topic: Batteries Discharging all 3 Modes, what is in common? (Read 2874 times) previous topic - next topic

Re: Batteries Discharging all 3 Modes, what is in common?

Reply #80 –
Quote from: Old Toolmaker –
Do you want a Megger that you crank?  Or one that looks like a multimeter built to fry electronics?


So, are you saying that the Multimeter type, Above can Fry Electronics? I might have to buy the Crank style , I have used before, that is all I ever used anyway! We had issues with digital Multimeters, Frying Circuit Boards, on the A6-E, Intruders in the 'Corps, we had the Top of the line Fluke 77's at the time in the late 70's - 80's! So some circuits required the Old but great Simpson - 260, Multimeter!  You also NEVER used a Digital type on an Armed Rail of any Aircraft, as stray Output Voltage could Pickle a Bomb or Missile to actuate and go BOOM! ;) The 1967 USS Forrestal historic epic fire was possibly the culprit of such uses of a Digital!

Re: Batteries Discharging all 3 Modes, what is in common?

Reply #81 –
I have never seen a megger, either battery operated or crank type that not produce a current. If it doesn't , wouldn't it just be an ohm meter?https://www.marineinsight.com/marine-electrical/construction-and-operation-of-megger-explained/

Re: Batteries Discharging all 3 Modes, what is in common?

Reply #82 –
Lynn bought one of these for use on the last real job we had.

Insulation Testers, Resistance Testing, Megohmmeter Testing | Fluke

The problem comes in when the un-initiated try to use the multimeter functions and "push the button."  You can do damage to electronics with a regular ohm meter, the high voltage necessary for a mega-ohmmeter is guaranteed to fry electronics.

As a gifted but sometimes slow witted toolmaker, Lynn relegates me to using VTVM, crank type meggers and any oscilloscope he doesn't care about.  Giving me time to realize my error before frying stuff.

Re: Batteries Discharging all 3 Modes, what is in common?

Reply #83 –
Quote from: RetiredGuns –

Who knows how many people have tossed their Xantrex, Inverter/Charger, because of the same Issue, perhaps?

Anyway, that is MY conclusion, on that!  Hope that can help someone in the future, as well?

Count me as one who could have used this information years ago. 

Ten years ago I burned up a thousand dollars of house batteries with charging voltages spiking up to 27 volts .  After talking to techs at ProSine I concluded my inverter/charger was badly malfunctioning and replaced it for another coach buck.  Now, after reading about your experience I probably could have saved myself many headaches and dollars by simply tightening a couple of bolts. 

Thanks for sharing, and like you I hope this helps others. 

Richard

Re: Batteries Discharging all 3 Modes, what is in common?

Reply #84 –
Have never used a megger on electronics, always on motors, generators, big transformers etc.
As they produce 250, 1000 or more volts I can see why it would be a bad idea.
A multimeter also uses voltage to measure resistance, but is usually far less than 10 volts.

Re: Batteries Discharging all 3 Modes, what is in common?

Reply #85 –
For 95% of electric diagnosis on a motorhome's 12 VDC and 120 VAC system, a simple digital voltmeter is all you need.

Re: Batteries Discharging all 3 Modes, what is in common?

Reply #86 –
I have all of Klein's digital meters including the true RMS clamp meter. They have saved me a ton finding a shorted knob and tube fault when an electrician and two assistants could not find it but charged me $250. I did have to drive 500 miles but.

The meter I use most is the Harbor Freight digital multimeter for $6.39. Reads the same voltages as the Klein and I give them for stocking stuffers at Xmas. https://www.harborfreight.com/7-function-digital-multimeter-63759.html

Pierce

Re: Batteries Discharging all 3 Modes, what is in common?

Reply #87 –
Quote from: wolfe10 –
For 95% of electric diagnosis on a motorhome's 12 VDC and 120 VAC system, a simple digital voltmeter is all you need.

Fully understand that, Brett!  My issue is short of Rewiring the Entire Coach, I want to Fully determine that those Vermin, didn't destroy even more wiring, that is an Unknown, to bite me in the future!  Meters are handy, but knowing what can and will happen, when wires toast themselves, I want to bring out the Big Guns, to ensure that any issues like I have been having are not shutting me down again, like this! I removed 2 nests in the Under Floor Conduit!!! Insulation breakdown/EATEN, can be quite a Show Stopper, and I have quite a chore ahead of me!  I like challenges, so it's all good! It has been a pretty Harrowing Experience I do not wish to repeat, soon, though!  All the help, so far, from folks like yourself again, has been quite the Godsend!  Someday, perhaps, I too will reach your level of Expertise on Coach Issue Resolution, till then, I read, read, and do more reading about systems I have little knowledge of, and gain confidence, the more I delve into my Unknowns!  All this would been enjoyable, if this Journey itself wasn't so long and protracted, as it has become, as well!  As I said to my wife, every endeavor becomes an adventure, for me! ;)

Re: Batteries Discharging all 3 Modes, what is in common?

Reply #89 –
Quote from: RetiredGuns –
Fully understand that, Brett!  My issue is short of Rewiring the Entire Coach, I want to Fully determine that those Vermin, didn't destroy even more wiring, that is an Unknown, to bite me in the future! )

Yup, for tracing wires (vs solving charging problem) you are exactly on target.