Author Topic: EEVblog #712 - Uni-T UT71E Multimeter (Why Uni-T Meters Suck)  (Read 155994 times)

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Offline Lightages

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Re: EEVblog #712 - Uni-T UT71E Multimeter (Why Uni-T Meters Suck)
« Reply #450 on: February 23, 2015, 09:40:22 pm »
If a meter with the BS1363 fuses was rated at CATIII/250V, it would be legal.
 

Offline Wytnucls

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Re: EEVblog #712 - Uni-T UT71E Multimeter (Why Uni-T Meters Suck)
« Reply #451 on: February 23, 2015, 09:45:37 pm »
So if these meters with the BS 1363 fuses were rated for 250 volts RMS maximum they would be OK or not?
I don't think that there is a CAT rating for 250V. 300V or 150V only. Fuses also need to have a rating of 50kA or equivalent to voltage/lead impedance.
BS1362 are rated for 240V AC 6kA. There may also be an issue with the lack of a DC rating.
If I remember correctly, fuses must also be rated FF (very fast blow). The BS1362 is fast medium blow.

Bussmann fuse: http://docs-europe.electrocomponents.com/webdocs/0279/0900766b80279c60.pdf
« Last Edit: February 23, 2015, 10:18:16 pm by Wytnucls »
 

Offline Lightages

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Re: EEVblog #712 - Uni-T UT71E Multimeter (Why Uni-T Meters Suck)
« Reply #452 on: February 24, 2015, 12:56:06 am »
Yes, Wytnucls is correct. I spoke too quickly.
 

Offline soren

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Re: EEVblog #712 - Uni-T UT71E Multimeter (Why Uni-T Meters Suck)
« Reply #453 on: February 24, 2015, 04:00:07 am »
HRC fuses rated for 1000V are available in the 1.25" x 0.25" size from reputable manufacturers. That tells me that the 1" x 0.25" BS1362 fuse is probably good for at least 800V in practice.
 

Offline Wytnucls

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Re: EEVblog #712 - Uni-T UT71E Multimeter (Why Uni-T Meters Suck)
« Reply #454 on: February 24, 2015, 04:48:48 am »
What you're happy with is your personal choice.
What matters is that no meter can be legally sold in Europe fused with a BS1362 anymore, unless rated CAT II 150V perhaps.
 

Offline Lightages

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Re: EEVblog #712 - Uni-T UT71E Multimeter (Why Uni-T Meters Suck)
« Reply #455 on: February 24, 2015, 12:00:25 pm »
The point is that there is no 250V category, 150, 300, 500  600 and 1000V only.
« Last Edit: February 24, 2015, 01:57:30 pm by Lightages »
 

Offline rolycat

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Re: EEVblog #712 - Uni-T UT71E Multimeter (Why Uni-T Meters Suck)
« Reply #456 on: February 24, 2015, 12:18:51 pm »
The point is that there is no 250V category, 150, 300, 500 and 1000V only.
Probable typo there - that should be 150, 300, 600 and 1000V.
 

Offline Fungus

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Re: EEVblog #712 - Uni-T UT71E Multimeter (Why Uni-T Meters Suck)
« Reply #457 on: February 24, 2015, 12:30:45 pm »
only 150v ?  :o
arent those rather common in 250v AC plugs? not proper even for 250v ?

The two things aren't equivalent.

Mains plug fuses are there to cut the power if there's a short-circuit inside the connected device.

Multimeter CAT ratings are about protecting people from transient power spikes.

 


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