Fluke 28-II Advice On Incorrect Use - Page 1
Forum section: electronics / testgear

author: abid0011
author_rank: Contributor
timestamp: June 03, 2021, 10:30:01 pm
content: hi guys I own a fluke 28-ll multimeter and want to know about what happens if set the meter dial to microamps and the black test lead in COM port and red test lead in voltage port or in microamps port and start testing the voltage which is 220 volts AC.I am asking because an electrician came to my place and I offer him my fluke meter for troubleshooting. He set the dial to microamps and put the test leads on voltage which is 220 volts ac and when I ask him about this he said he also switch the red test lead to microamps and dial remain set on microamps.will this type of incorrect usage effects the meter accuracy or some little or severe damage to the meter.kindly give ur suggestion on this thank you

author: BeBuLamar
author_rank: Super Contributor
timestamp: June 03, 2021, 10:35:59 pm
content: As long as the red lead is on the VOhm jack there is no harm done but if it's on the mA/uA jack it would blow the fuse. The 0.400 A fuse. You shouldn't let an electrician use your meter. Give them one without the current function like the 113, 114 etc... If they need to measure current they would use the clamp meter. Many won't know how to measure current with the 28II.

author: retiredcaps
author_rank: Super Contributor
timestamp: June 03, 2021, 11:06:12 pm
content: I would NEVER willingly OFFER a Fluke 28 II, a $400 USD meter, to an electrician for use. Isn't a professional electrician supposed to have his/her own tools?

author: tautech
author_rank: Super Contributor
timestamp: June 04, 2021, 12:23:42 am
content: Quote from: retiredcaps on June 03, 2021, 11:06:12 pmThis ^.Any that ever turn up without their own gear should be quickly shown the door and be advised not to let it hit them on their way out !

author: james_s
author_rank: Super Contributor
timestamp: June 04, 2021, 01:33:53 am
content: The OP is in UAE, I know almost nothing of the culture there, perhaps expectations are different? That does seem strange though, an electrician should at the very least have a device capable of measuring AC voltage.Either way the important thing is to have the probes in the correct sockets on the meter. So long as nothing is plugged into the Amps socket no harm will come of the meter.

author: AVGresponding
author_rank: Super Contributor
timestamp: June 04, 2021, 06:02:45 am
content: Quote from: abid0011 on June 03, 2021, 10:30:01 pmQuote from: retiredcaps on June 03, 2021, 11:06:12 pmMost of the electricians I know (quite a few, I work as one for a city government) don't have a clamp meter; it just isn't necessary for most general installation/maintenance work. I have two, but then I come from an electronics background.The most common tool is a two-probe tester sometimes known as "Steinels" and these work only for voltage and continuity.I think there are maybe one or two others in the entire department I would trust with one of my meters...

author: Fungus
author_rank: Super Contributor
timestamp: June 04, 2021, 08:59:32 am
content: Quote from: james_s on June 04, 2021, 01:33:53 amMe? I'd settle for an electrician that knows the difference between volts and amps.Quote from: retiredcaps on June 03, 2021, 11:06:12 pmYep.(Image from"How to select a good electrician")

author: abid0011
author_rank: Contributor
timestamp: June 04, 2021, 09:00:51 am
content: Thanks for the reply. I myself use a clamp meter when need to measure current. the unfortunate thing is I leave that guy and went downstairs.suppose the red test lead is in mA/uA jack and the max damage is blown fuse? or it will go further than that.the other thing is how to test the meter if the fuse is blown or not or how to test the meter to assure the meter is working fine.kindly advise on this will be a great help.

author: Fungus
author_rank: Super Contributor
timestamp: June 04, 2021, 09:02:39 am
content: Quote from: abid0011 on June 03, 2021, 10:30:01 pmHopefully not. Ability to survive this sort of mis-use is the reason that people pay $400 for a Fluke.It's not 100% clear from your description but he may have blown a fuse inside the meter. Try measuring uA and see if it works or not. If it doesn't then you need to open it up and change the fuse.

author: Fungus
author_rank: Super Contributor
timestamp: June 04, 2021, 09:06:21 am
content: Quote from: abid0011 on June 04, 2021, 09:00:51 amTwo methods:a) Measure mA or uA (it's the same fuse) against a known reference or against another meter.b) Open up the meter, pull the fuse out, use the continuity test function to test the fuse. If it beeps then it's still good.

author: AVGresponding
author_rank: Super Contributor
timestamp: June 04, 2021, 09:14:18 am
content: Quote from: abid0011 on June 04, 2021, 09:00:51 amFluke meters are very robust. I can't think of any way the meter could be damaged in the circumstances you outlined. The likely outcome is a blown (expensive) fuse, and you can verify if the fuse is good by the meter beeping and displaying "LEAD" with the leads in the uA socket when the range switch is set to a non-current range (this is how it works on my 87V and I think it's the same on your 28 Ex).

author: BeBuLamar
author_rank: Super Contributor
timestamp: June 04, 2021, 01:41:32 pm
content: Quote from: abid0011 on June 04, 2021, 09:00:51 amYou can test the meter as per the manual instructions. Connect the test lead to the volt/ohm port. Set the meter in ohm mode. Try to touch the top half of the A or mA port with the tip of the probe. Should have low ohm readings. If it reads OL the fuse is blown. The sure way is to remove the fuses and check with the Ohm function.Other than the blown fuses I do not think any further damage is done.

author: BeBuLamar
author_rank: Super Contributor
timestamp: June 04, 2021, 10:45:02 pm
content: I would remove the fuse and check. I think it's bad. I think the fact that it beeps and said "LEADS" only because it detects you insert the lead in the wrong port for the function. I know other posters said if it beeps it's OK but I do think the 440 mA fuse is blown.I actually blew the 10A fuse quite often as I use the A function of the meter a jumper and I know it only blew the fuse. No other damage is done.

author: abid0011
author_rank: Contributor
timestamp: June 04, 2021, 11:22:50 pm
content: Quote from: BeBuLamar on June 04, 2021, 10:45:02 pmDear, I remove the fuse and check the continuity and the fuse is blown.so I hope the is the only damage is happen which is only the blown fuse.I Check on a local online store they listed Fluke 943121: 440mA/1000V Fuse and on the fluke website the part fuse number is P/N 203411 for 28-2440 mA 1000V. can I use the Fluke 943121: 440mA/1000V fuse

author: J-R
author_rank: Super Contributor
timestamp: June 04, 2021, 11:40:13 pm
content: That fuse will be fine according to this:https://web.archive.org/web/20210118203043/https://techsupport.fluke.com/hc/en-us/articles/360048753812-Fuse-list-for-Fluke-Meters"0.44A/1000V P/N 943121 (O) or 203411 (BP1) or 203414 (BP5)"

author: J-R
author_rank: Super Contributor
timestamp: June 05, 2021, 12:17:47 am
content: Official confirmation from the 28 II manual:https://dam-assets.fluke.com/s3fs-public/2x_2____umeng0100.pdfPage 41 lists "943121" as the part number.

author: abid0011
author_rank: Contributor
timestamp: June 05, 2021, 01:25:52 am
content: Quote from: BeBuLamar on June 04, 2021, 10:45:02 pmDear i read the manual how to test the fuses as you mention above same mentioned in the manual.And it also says text quotes from manual ( The resistance value should be as shown in Figure 10. If the tests give readings other than those shown, have the Meter serviced.)The ohms reading for the 440 microamps are 0.995 kΩ to 1.005.Do u think after replacing the fuse there is chances for the ohms reading to not as in above range and need to send to service.Thanks you

author: Fungus
author_rank: Super Contributor
timestamp: June 05, 2021, 04:47:04 am
content: Quote from: abid0011 on June 05, 2021, 01:25:52 amI think there is a 0.12% chance.

author: abid0011
author_rank: Contributor
timestamp: June 05, 2021, 07:03:34 am
content: haha, so it means there is no chance that the reading after replacing the fuse not within the specs.thank You

author: AVGresponding
author_rank: Super Contributor
timestamp: June 05, 2021, 08:14:15 am
content: Quote from: BeBuLamar on June 04, 2021, 01:41:32 pmAh, that's the same method as the 289, my bad.The main reasons for using the test methods described rather than opening the meter are convenience (not having to remove the boot on something like an 87V), and avoiding wear and tear on the plastic battery/fuse door retaining catches. Also the battery springs are reportedly fragile on the 289, though I've not had any issues with mine (fingers crossed).

author: Fungus
author_rank: Super Contributor
timestamp: June 05, 2021, 10:29:21 am
content: Quote from: abid0011 on June 05, 2021, 07:03:34 amNo, it means there'salmostno chance.Never say never!

author: BeBuLamar
author_rank: Super Contributor
timestamp: June 05, 2021, 11:06:04 am
content: Quote from: abid0011 on June 05, 2021, 07:03:34 amNow I don't know how the meter is built exactly but I think the current measuring ports are not connected to the Ohm measuring circuit so it won't affect the Ohm measuring function. Over current the current shunt can damage the shunt resistors but the fuse is there to protect them.

author: abid0011
author_rank: Contributor
timestamp: June 05, 2021, 11:37:24 am
content: I attached images from fluke 28-2 manual.Describe how to test fuse.

author: BeBuLamar
author_rank: Super Contributor
timestamp: June 05, 2021, 12:23:22 pm
content: Yup that's what I thought. You put the lead in too fart and it display "LEADS" so it's a bit tricky. An easy way is to use another meter and measure resistance while the meter is setup for current measurement.