how to compute for fuse amperage?

[poobah]

Andrew,

At the bottom of the SMILIES box, in the reply window/page there is a link, "[Get More]". A second window will pop up and you can stretch it out larger.

I have memorized some like:







Use colons instead quotes around the name of the smiley.

 

[jarthel]

to anatech

I was right about connecting the vom in series with the hot wire

though I didn't realize it at first that it's easy enough to calculate amperage using ohm's law

 

[anatech]

Hi Andrew,

are there many countires that use fused plug tops?

We don't in North America. UL and CSA would just freak out!

Poobah, yer :wink: doesn't.

I also like : and

-Chris

 

[anatech]

Hi jarthel,

I was right about connecting the vom in series with the hot wire

Not in the context of the discussion. You would have been in the volts function.

I don't like sticking a meter in series. I've seen too many blown ones as a result.

-Chris

 

[jarthel]

to anatech again

can I use 0.1ohm 5W ceramic wirewound?

 

[anatech]

Yes, just make sure it doesn't touch anything else. Connect the meter leads across it before applying power. Set on AC volts.

-Chris

 

[poobah]

Not so fast jarthel... the first method was 'bout measuring a VOLTAGE across a RESISTOR in series. The second method is about placing the meter series and directly measuring the current.

 

[poobah]

I don't like measuring in series either. I got so tired of my guys burning up $200 meters by cheating the fuse that I filled the "current" banana socket with epoxy and bought them all current clamps.

 

[anatech]

Hey poobah,
That's the spirit! Don't let stupidity claim another meter.

They normally forget to change the leads over and then go measure 550. Many Fluke 87's died that way.

-Chris

 

[poobah]

I can't remember if they were 83's or 87's or or what... I do remember the $200 though. I think the currentr clamps were about $80 at that time...

 

[anatech]

Hi poobah,
Isn't it just sad and frustrating to have meters killed that way?

Jarthel, don't add to the number of dead meters, or techs.

-Chris

 

[billdinva]

To measure the real time AC amps/volts/watts/VA/hz/power factor, get one of these. Completely safe. http://www.p3international.com/products/special/P4400/P4400-CE.html

For fusing a low power transformer, try a slow blow at the rated amps of the primary as a starting point.

 

[anatech]

Hi billdinva,

how to compute for fuse amperage?
Mains here is 220-240VAC 50/60Hz.
current load of the system

Won't work. I have my doubts on the 0.2% accuracy thing too.

For fusing a low power transformer, try a slow blow at the rated amps of the primary as a starting point.

That's been suggested earlier, I disagree. There is already a thermal fuse for that. You want to protect against abnormally high current for the circuit. It's not that difficult to figure out.

-Chris