Multimeter Classes

[LavaASU]

I've been hunting for a class 3 multimeter since I know I have some things coming up where I'll need to check at the company switch/ genny/ distro and also would like a clamp meter. In the past I've always just used my home depot one which is class 2 (didn't pay attention when I bought it-- ironically to make sure we had one to check a genny). My question is how many people really know/ make sure they use the correct class of DDM? Why or why not?

[LavaASU]

I'm looking for 2 different types:

1. A reasonably good class 3 multimeter with amp clamp. Needs to be something that is pretty accurate (within a volt or so at 120/208/240 and within .1 MAX at low voltages), can stand up to reasonable abuse, and isn't terribly expensive (so I won't cry if it grows legs).

2. Cheapo but reasonably accurate class 2 meters to have in work boxes/ onsite for typical gigs. These unfortunately probably will walk, so cheap is good. Theres several flavors available on amazon for $4-10 as well as ebay and harbor freight. Anyone have experience with these and know which are ok and which are horrible (not expecting good).

[derekleffew]

1. A reasonably good class 3 multimeter with amp clamp. ...

See the thread Clamp Meters .

[avkid]

I have one of these kits, and as long as you don't freeze it they both work great.
(when the LCD screen freezes you're in trouble until it thaws out)
TK430 - Electrical Test Kit

[Chris15]

Would not the output of a genny be an "origin of installation" and thus need a Cat IV meter?

[LavaASU]

Would not the output of a genny be an "origin of installation" and thus need a Cat IV meter?

Probably according to NEC or whoever wrote the class guidelines, however from a safety standpoint, even in a fault condition, that genny isn't going to be able to throw any more at you that a 400A 3-phase disconnect. Well, all bets are off if lightning is involved, but personally I'm willing to take my chances on that account. However that said I don't object to class 4 other than on price.

[bishopthomas]

I use a Fluke 73-III. Fluke has it listed as a Category II but it's worked fine for my use.

[Arez]

Both of my Ideal meters and my Fluke are Cat. III-600V, I don't know what my old analog is rated at, if at all, it's only used for testing LEDs.

[Sony]

I have a Fluke 117, it's Cat III

[cpf]

Oops selected the wrong one (and managed never to actually press Submit Post on this earlier). Move 1 Class II vote to class III.

[mstaylor]

I use a Fluke clamp style but not sure of the model, it is a type III.

[bishopthomas]

Both of my Ideal meters and my Fluke are Cat. III-600V, I don't know what my old analog is rated at, if at all, it's only used for testing LEDs.

600V = Cat III ? Mine is for 600V but Fluke has it listed as Cat II...

[Arez]

600V = Cat III ? Mine is for 600V but Fluke has it listed as Cat II...

No, category and voltage are two different things that are listed together.

Category is when/where/what you can use it, as defined by Category I through Category IV.

The voltage listed following it is the maximum voltage you can use it in that category. Each category rating has multiple max input voltages such as 150V, 300V, 600V, 1000V depending on the meter. Beyond that and you want to look at transient protection.

[avare]

600V = Cat III ? Mine is for 600V but Fluke has it listed as Cat II...

This Fluke Document may help explain the difference between voltage rating and category.

Andre

[STEVETERRY]

Err....that would be meter category not class.

ST

[Dionysus]

Err....that would be meter category not class.

ST

Two Steves think alike, I just read the title of this thread and thought "a class on how to use a multimeter?". Then immediately went "oooohhhh CATegory!".

To answer the OP question, I usually use a CAT III, because I usually have one handy as I keep my CAT IV put away for when I need it. Tools like to "walk away".

I NEVER use a CAT II. Then again if I got caught by the Ministry of Labour it would not be good... Meanwhile without PPE.

Ugg having your arc-flash training, makes it so you have no excuse. Because "bomb suits" and full face shields or even just Class 0 or 00 gloves are so much fun...