Got Ampere metering in a wrong way with Brymen BM829s - Page 1
Forum section: electronics / beginners

author: dark.viking
author_rank: Newbie
timestamp: October 06, 2021, 07:03:45 am
content: Hello good people!Need some help with my multimeter - Brymen BM829s.I'm a beginner to clarify ))So, I've done the BIG mistake by using the DMM for taking A measurements directly on a 220V socket. And the house circuit responded with a nice spark.I was completely wrong with this. Already know this.However, how can I check that the DMM is working?And how can I check the fuses?I assume that the fuse on 10A is broken.There is no more "beep jack" sound for input error on the Brymen, as it was before.When I tried to check the resistance (with the same DMM), there was a signal on µA probe input, but there was no signal on A/mA input. Does it mean that the fuse is dead on A/mA?P.S. I do not have another multimeter to do some direct tests.Any hint or assistance will be really appreiated.

author: Jwillis
author_rank: Super Contributor
timestamp: October 06, 2021, 02:07:30 pm
content: You won't do that again will you ? You'll have to open the meter up. There should be 2 fuses . One should been 10A and one should be around 600mA . Pull the 10A fuse and check for continuity . If no good , replace fuse and see if the meter works. Also check the smaller fuse and replace if required.If the meter does not work then you'll have to buy another one.And stop messing around with mains power until you have a lot more experience . Please.

author: rsjsouza
author_rank: Super Contributor
timestamp: October 06, 2021, 02:29:07 pm
content: You can check the meter by trying the other ranges (V/Ω) to see if they are working fine.As Jwillis said, to verify and/or replace the fuse you need to open the meter. The post below shows a few pictures of its internals and the 10A is the one on the lefthttps://www.eevblog.com/forum/testgear/timing-brymen-829s/msg934293/#msg934293(edit: much better pictures)To test if the fuse is working, you can either make a simple circuit with two AA cells, a LED and a few wires to see if the LED lits up when it connects to the fuse.|\ |______________| \|__________| | /| || |/ | || LED |___|___ ---___ 2 x AA | |_______ (3V) | | Fuse___ | || ---| ||__________________________|Also, I reiterate what Jwillis said: don't do this again. We have all done such things and Iknowby now that you will never forget this experience. Good luck!

author: tunk
author_rank: Super Contributor
timestamp: October 06, 2021, 06:59:03 pm
content: Do the other ranges work - e.g. does a new AA cell show ~1.6V?Or if you short the probes in the resistance mode?

author: BeBuLamar
author_rank: Super Contributor
timestamp: October 07, 2021, 01:03:15 pm
content: I think your meter is fine except the 10A fuse is blown.

author: TimFox
author_rank: Super Contributor
timestamp: October 07, 2021, 02:05:14 pm
content: Note that the proper replacement for the 10 A fuse will be expensive: they are safety-rated to keep the meter from blowing up in your face when you connect line voltage to the ammeter.

author: rstofer
author_rank: Super Contributor
timestamp: October 07, 2021, 03:33:57 pm
content: EEVblog store has fuses but I don't know if they are correct for your meter.https://www.eevblog.com/product/multimeter-fuse-pack/I wouldn't worry a lot about 11A versus 10A, the fuse is really there to protect against 1000A faults.

author: tunk
author_rank: Super Contributor
timestamp: October 07, 2021, 04:24:17 pm
content: Or just remove the fuses, and reinstall them when you've got more experience.

author: dark.viking
author_rank: Newbie
timestamp: October 08, 2021, 12:48:12 pm
content: Thanks to all!And no, will not do it againSo, after doing some tests, the meter works fine.But the 10A fuse is dead. Will need to order it and replace. It has Bussmann fuse BM-S/FUSE-11A.By the way, the method with continuity test using the DMM's own probe also works. Got the signal on mA input and no signal on A input.

author: dark.viking
author_rank: Newbie
timestamp: October 08, 2021, 12:53:41 pm
content: USD 11-12, as I have been able to find

author: Terry Bites
author_rank: Super Contributor
timestamp: October 08, 2021, 01:23:11 pm
content: We've all done it!I did it to one of these when I was a kid. It seemed like a good idea at the time, I'd just meaured the line current on our phone line. What could possibly go wrong?

author: rstofer
author_rank: Super Contributor
timestamp: October 08, 2021, 02:01:11 pm
content: Quote from: tunk on October 07, 2021, 04:24:17 pmThat's not a bad idea! I had thought of just plugging the current input jacks with epoxy but your idea is more easily reversible.It's pretty rare that I actually want to break into a circuit and measure current.

author: radiolistener
author_rank: Super Contributor
timestamp: October 08, 2021, 06:52:18 pm
content: Quote from: dark.viking on October 06, 2021, 07:03:45 amSuch experience helps to learn that any measurements and connections on the mains needs double checking before any actionI remember my experience with that, in my case I got burned out DM830 and melted probesIt also helps to understand why a good branded CAT IV 1000V probes and DMM are better than Chinese cheap crap.If something will going wrong, good DMM and good probes that meets safety requirements can save your life or at least help to avoid injury and burns

author: Vovk_Z
author_rank: Super Contributor
timestamp: October 08, 2021, 11:16:51 pm
content: Quote from: dark.viking on October 06, 2021, 07:03:45 amA very strange situation when you have only an expensive Brymen DMM and don't have another cheap one.

author: Vovk_Z
author_rank: Super Contributor
timestamp: October 08, 2021, 11:18:50 pm
content: Quote from: dark.viking on October 08, 2021, 12:53:41 pmYou may use any other cheap fuse until you work only with low voltages.

author: Trader
author_rank: Frequent Contributor
timestamp: October 09, 2021, 01:28:09 am
content: Don't worry, I did the same, but my DMM cost $18.My DMM still working in ALL measures correctly, except the Current.Quote from: dark.viking on October 06, 2021, 07:03:45 am

author: BeBuLamar
author_rank: Super Contributor
timestamp: October 09, 2021, 02:04:15 pm
content: Quote from: rstofer on October 08, 2021, 02:01:11 pmThere are 2 sides to this.1. As you said in normal troubleshooting in an industrial enviroment there is very little need to use a DMM to measure current. Almost all current measurements are done with a clamp meter. Very rarely I do need to measure the output of a 4-20ma transducer but that's rare. So for this I have used the Fluke 12, Fluke 114 and Fluke 113 all don't have the current measuring function. No A jack.2. But I do find a use for the current measurement function of a DMM. When in the 10A range the resistance of the meter is less than 1 ohm and thus it's good to use as a jumper. The probes are good to touch the points you want to jump than a piece of wire (if you have a piece of wire handy). If you make a short it would blow the fuse much better than a piece of wire. But doing so many times I forgot to put the lead back to the right port and thus blowing the fuse.

author: TimFox
author_rank: Super Contributor
timestamp: October 09, 2021, 03:41:00 pm
content: I often use the mA and A ranges to measure current in low-voltage (< 50 V) circuits by connecting the DVM with normal banana plugs between the lab power supply and the relevant circuit, especially when measuring more than one load from a single supply (with more than one DMM). I built a separate metal box for measuring AC current in 120 V circuits, with a fuseholder, that uses a simple current transformer (readily available from distribution) and appropriate load resistor to drive a grounded AC voltmeter.

author: Vovk_Z
author_rank: Super Contributor
timestamp: October 09, 2021, 04:31:49 pm
content: Quote from: TimFox on October 09, 2021, 03:41:00 pmI built a plastic box (for 220/230VAC tests) with different shunts (1R, 10R, external lamp) switched by a switch, a Chinese panel LCD meter (power-voltage-ampere-PF-multimeter), and an output standard socket, and two output clamps. It is powered via isolating 400VA power transformer. By default, I use "a lamp" position in my switch (a 40W lamp is ok for most of my work). It has an easily changeable fuse too (for example, to test a fuse rating for a new device).

author: Monkeh
author_rank: Super Contributor
timestamp: October 09, 2021, 06:49:41 pm
content: Quote from: BeBuLamar on October 09, 2021, 02:04:15 pmThey make fused jumper wires, resettable short finders, and so forth for exactly this purpose..

author: dark.viking
author_rank: Newbie
timestamp: October 16, 2021, 09:45:56 am
content: Totally agree !!!

author: dark.viking
author_rank: Newbie
timestamp: October 16, 2021, 09:47:37 am
content: Single meter is more than enough for me ))The cheap one has fallen into pieces long time ago.

author: t1d
author_rank: Super Contributor
timestamp: October 17, 2021, 11:10:50 am
content: Please be forewarned that these type of fuses arehighlyfaked on Ebay/Amazon/etc. And, the genuine ones are often not cheap. But, I (IMO) emphatically recommend that you go to the effort and expense to source genuine, OEM, identical fuses.

author: BeBuLamar
author_rank: Super Contributor
timestamp: October 17, 2021, 12:08:17 pm
content: The fuse cost me $14.

author: dark.viking
author_rank: Newbie
timestamp: December 26, 2021, 07:55:01 pm
content: Sure, I know that.We have an authorized dealer in my country. This company sells all the original accessories for Brymen.