Releasing the Magic Smoke

[rvpopeye]

If it makes you feel any better , I just made 10 posts trying to sell crap from China evaporate ...........figuratively gone in a puff of smoke.

[sternwake]

Was glad to see those posts got zero views.

Got a 28$ refund for the 1800 watt V booster which smoked a wattmeter, and found some oragel in my junk drawer.

[weigh2ez]

The "magic smoke" theme mad me think back about 40 years ago I drove a Courier pickup and it kept blowing a fuse that made the truck die. One day I was in the middle of Nowhere West Texas and it died on me again.  I was out of fuses so I took a piece of foil and wrapped the blown fuse and clicked it back in the fuse block, turned on the key and waited.  Sure enough, there was the magic smoke right where a bare wire was rubbing against part of the engine.  Turned off the motor taped up the wire and headed down the road.

[sternwake]

The 100 amp metal enclosure wattmeter showed up, but it took a while before I tested its accuracy.

It reads 0.06 to 0.09v too low. Annoying.  But the amperage is quite accurate at least int the ranges tested too far,  and it also seems to read a bit higher than actual at low currents whereas every other seemed to stop reading currents below 0.12 or so.

I did a precise  1 hour timed test at 1.05 amps  and Ah did read a smidge high at 1.103AH.  It does not have its own time display as does the 200 amp model,  but the 200 amp models timer is off by several minutes each hour and as such the timer is worthless anyway.

This metal enclosure blue anondized aluminum,  is really nicely built, but the electronic guts are pretty much not secured within it. The input and output wires and some soft pads keep it in place within.

I was considering replacing the super flexible silicone encased  14awg with 12 or 8, then saw there was no way the 8awg could fit as it needs to go in between the circuit boards, and there is not adequate room on this model. The 12awg would have fit but i said F it and just put some new 45 amp anderson powerpoles on the 14awg in two crimp stages, then covered them with solder.

  For 11$ it is Good enough wattmeter, and I will not be passing starter motor current through it anyway.

Both of the newest wattmeters will have their voltage and amperage jump around when feeding one of my voltage buckers which is controlling a fan or LEDS, but in general the highest amperage and voltage they read when jumping, are the figures to be trusted.  Perhaps some snap on  ferrites closer to the device being powered will attenuate the instability of readings. perhaps nothing will.

Honestly, since the 200 model is quite accurate for AH and voltage I am considering getting anopther despite the KWH and timer being off.  I've also been considering a different measurement device for the output of my Meanwell power supply. The surge/peak amps and watts are not all that important to be recorded. The AH delivered figure would be 3rd most useful reading in that location.

[Roadtripp]

Interesting. I had no idea there was so much variation in power electronics. I’ll remember that if they ever put a pacemaker in me. Would there be much variation in a production run of the same model clone meter? Could you just keep sending them back until you find one that is more accurate?. Us consumers need to keep the seller informed and honest. But what a pita shipping things can be! Sometimes they don’t want the defective item back however if it’s a inexpensive electronic item. 
 That anodized aluminum box sounds nice. I could use a handful of those for when I set up the little test bench.

[Roadtripp]

weigh2ezThe "magic smoke" theme mad me think back about 40 years ago I drove a Courier pickup and it kept blowing a fuse that made the truck die. One day I was in the middle of Nowhere West Texas and it died on me again.  I was out of fuses so I took a piece of foil and wrapped the blown fuse and clicked it back in the fuse block, turned on the key and waited.  Sure enough, there was the magic smoke right where a bare wire was rubbing against part of the engine.  Turned off the motor taped up the wire and headed down the road.
Those were the days when we could see the engine and the wires. Now there’s so much stuff it seems overwhelming. You could probably have hot wired that Courier pretty easily if you needed to. Always good to keep a few feet of wire around.

[Blacktank]

my 2x multimeters read almost 0.2 less volts than my charge controller,so go with the multimeters right? until i hooked up the amp meter and it read the same as the charge controller

pretty sure you will have to spend some nice coin for a well calibrated tool to get a good reading,especially if your going to the hundredths

[Scott7022]

Irony

When your helper connects your Fluke meter to an incorrect line.

It now releases magic smoke and your magic smoke discerning tool is pooched.

36 inch breaker bar discipline time!!!

Luckily it was fuzed and so did not fuze the board.

[sternwake]

I don't mine 3 or 4 hundreths of a volt reading off, 5 or 6 get a bit irritating, but a full tenth of a volt is a lot, especially for a 'precision' instrument.

Of all the wattemters I have opened, they all have the same two layer circuit board, and the ground wires get soldered to a Shunt in between the CB's. The shunt has been slightly different on some, and if it reads too low I successfully ground enough shunt away to get it to read inline with my other trusted meter, but then the display failed.

The 100 amp rating of the aluminum cased meter compared to 200, besides 14awg vs 8awg leads, could just be the extra ventilation holes provided to the 200's casing. the 100 has only one slit on one side, no cross ventilation holes elsewhere.

My spreading the circuit boards apart to get a good reach on the shunt's solder connections could have lead to at least one of the wattmeters reading amperage when squeezed back together when no loads were running through the meter.

I'm not really keen on sending back the inaccurate ones and playing merry go round with USPS, not for a sub 20$ product, and testing them for amperage requires some better connections than alligator clamps.

Whether my trusted digital clampmeter meter is to be trusted is another matter. I calibrated the voltage of my cheapo Centech from this meter. Other meters in the past have read a few hundreths lower. If I use NImh rechargeables in my clampmeter the readings are way too inaccurate to be useful. Got to use Alkalines in it.

Gary, My Bayite hall effect sensor ammeter/voltmeter combo read 0.2v low compared to all other voltmeters, but In never displays its voltage anyway.

I'm thinking of a shunted meter for the output of my Meanwell power supply instead of gtpower wattmeter number one which has been attached to it since 2014. That will free up one wattmeter with pretty long 8awg leads.

[Snikwahjm]

Pasemakers have the added problem of becoming infected.