Posted: 6/8/2009 5:46:48 PM EDT
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When switching from testing a resistor to 480VAC, what can be done that will fry a Fluke digital multimeter?
If you leave it on a resistance setting, can that hurt it? Or if you flip the selector while probing 480V, can that hurt it? It happened to our electrician at work today. |
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Quoted:
Yes.
If you leave it on a resistance setting, can that hurt it? Or if you flip the selector while probing 480V, can that hurt it? Yes.
It happened to our electrician at work today.
You need to find a smarter electrician - The one you have probably isn't going to be around much longer... |
| I'm servicing the whirlpools and often have to use my ohmmeter on my Fluke to trip the GFCI if owner is not home and there is no quick disconnect or breaker outside. I touch the hot and the ground and GFCI trips. Never had problem with the meter. If I touch 220V with both leads with setting on ohmmeter display just flickers. |
hmmm. I've measured up to 700VDC no prob with a Fluke 87. I have no idea why the above scenario would take place. I, however would never put one on anything over that. A couple guys I worked with killed some on a 5 amd 8 Mwatt output induction furnace. The input was about 1100V 3 phase. Not sure where they put the leads.
ETA- The damage was much worse than a blown fuse. |
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Quoted:
Quoted:
Yes.
If you leave it on a resistance setting, can that hurt it? Or if you flip the selector while probing 480V, can that hurt it? Yes.
It happened to our electrician at work today.
You need to find a smarter electrician - The one you have probably isn't going to be around much longer... I'm not sure what he did, which is why I'm asking. I'm sure he did something wrong, but it wasted an hour of my time while he tried to figure out why he couldn't find electrons anywhere. |
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Quoted:
Quoted:
Quoted:
Yes.
If you leave it on a resistance setting, can that hurt it? Or if you flip the selector while probing 480V, can that hurt it? Yes.
It happened to our electrician at work today.
You need to find a smarter electrician - The one you have probably isn't going to be around much longer... I'm not sure what he did, which is why I'm asking. I'm sure he did something wrong, but it wasted an hour of my time while he tried to figure out why he couldn't find electrons anywhere. Tell him to get out his sub-atomic microscope or particle accelerator to see the electrons!!!  
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I frequently check resistence in live circuits (fuses for example) and sometimes I then go check a circuit with voltage potential while meter is still on ohms. The fuse in the meter is for the AMP test so you don't pull a high current through meter and melt internal components. If meter is a Fluke I would have no problem testing anything on even a incorrect setting so long as voltage would not exceed 600volts with a class 3 meter. If meter blew, I am sure Fluke would like to see it, besides Fluke will fix any of their meters for flat 50.00 fee as long as they have parts. If it's a newer meter it may be covered under their lifetime warranty.
ETA DO NOT CHECK ANYTHING OVER 120VOLTS WITH CHEAP RADIO SCHACK TYPE METER |
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Quoted: When switching from testing a resistor to 480VAC, what can be done that will fry a Fluke digital multimeter? If you leave it on a resistance setting, can that hurt it? Or if you flip the selector while probing 480V, can that hurt it? It happened to our electrician at work today. I did that.  Yes, it fried my multimeter, poor little internal fuse never stood a chance. It also melted a 1/2 inch off the ends of the probes. |
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Don't leave one on the belt of a gas fired belt furnace running at 850 degrees F. There won't be much left when it comes out the other side.
Guy that used to work for me tried it, once... I would say that probing 480V while set for resistance shouldn't damage the meter unless it was done repeatedly. Switching modes while connected to a live circuit is a definite no-no. |