Reddit mentions: The best clamp meters

I was concerned about drilling any holes in my roof. Being a born pessimist, I figured if anything can go wrong, it will go wrong. The fewer holes in my roof the better.

I started looking for a roof rack. What I really wanted was a full-length roof rack with a diamond-pattern, "hardware cloth" platform surface upon which to mount my solar panels. All the racks I could find were around $600. Getting a rack custom built was estimated at $1300. Too much.

I finally found a very heavy-duty-looking rack made of black-painted round tubing for $311. "That's more like it," I thought. I ordered it off the internet.

When it arrived, I was annoyed to see that all the parts weren't there. Two long side panels seemed to be missing. I called the vendor, and after a very confusing conversation, it turned out that I had only ordered "half" the rack. The other part number was the side panels. Guess how much they cost? $300. ($611 for the whole rack. Dammit.)

Once I got the whole rack at my house, and started trying to install it, I realized that it's a two-or-three-man job. I finally got it installed, but Lord, what a pain in the ass!

I bolted a piece of 4x8 plywood to the rack tubing using large U-bolts. The PV panels bolt to the plywood.

I feel pretty sure that bolting the panels directly through the roof would work just as well, maybe better.

A really good book that describes solar panel installation is "Photovoltaic Design & Installation for Dummies" by Ryan Mayfield. He is the president of the Renewable Energy Associates solar power company.

A solid wire is called a "wire." A bundle of wires together covered with plastic insulation is called a "cable." You want cables of at least 6 gauge diameter. (The smaller the gauge number, the larger the cable. I know, it seems backwards.) A lot of solar power kits come with 8 gauge or even 10 gauge cable. TOO SMALL. Cable this small is inefficient for DC current, for our purposes.

You will need a "cable gland" (Amazon) and a good quantity of "Dicor self-sealing lap sealant." (Amazon). Be generous with the Dicor. Every time a cable goes through a steel bulkhead or floor you MUST put a grommet of some kind (rubber, plastic) there to protect the cable insulation. If you ground out a positive cable, it could cause a fire. Ground the negative (black) cable of the system TO THE VEHICLE'S FRAME, directly to clean steel (NOT PAINTED STEEL), through the floor. Bolt the ground cable connection securely to the frame. Don't forget the grommet.

https://www.amazon.com/Link-Solar-Weatherproof-Project-Campervan/dp/B0111RNZDY/ref=sr_1_2_sspa?ie=UTF8&qid=1506480381&sr=8-2-spons&keywords=double+cable+gland&psc=1

https://www.amazon.com/Scosche-WPG8-10-Gauge-Waterproof-Grommets/dp/B00OYGLP32/ref=sr_1_12?ie=UTF8&qid=1506480517&sr=8-12&keywords=8+gauge+cable+grommet

https://www.amazon.com/Auto-ranging-Multimeter-Resistance-Capacitance-Frequency/dp/B01N014USE/ref=sr_1_14_sspa?s=automotive&ie=UTF8&qid=1506480598&sr=1-14-spons&keywords=clamp+style+multimeter&psc=1

https://www.amazon.com/dp/B00NWGZ4XC/ref=dp_cerb_2

Always use BLACK cable for the negative (ground) side of the circuit and RED cable for the positive side. This will prevent you from screwing up and short-circuiting your system. Hopefully.

Do not hook up the PV panels until everything else is installed and you have tested it for continuity with a digital multimeter (DMM.) The kind that has a "clamp", automatic ranging, and an audible alarm is best. (It looks kind of like a lobster claw and doesn't necessitate puncturing the insulation of the cables.) You start wiring from the storage battery bank and work backwards to the PV panels. Keep in mind--if those panels are exposed to the sun, they are GENERATING ELECTRICAL CURRENT POTENTIAL. Cover them with cardboard or heavy paper and tape until you are ready to energize the system. You don't want to get electrocuted accidentally. The risk of shock is small, but it does exist.

You need either a fuse (good) or a DC breaker (better) between the positive cable between the PV panels and the charge controller, and also between the charge controller and the battery bank. If you install an inverter, you need a breaker on the positive cable between the battery bank and the inverter. (Inverters burn amps just sitting there hooked up. You need to be able to "turn off" the DC power supply to the inverter. Turn the power to the inverter back on to use it.)

https://www.amazon.com/MidNite-Solar-Photovoltaic-Circuit-Breaker/dp/B004EQK8SA/ref=sr_1_7?s=automotive&ie=UTF8&qid=1506481155&sr=1-7&keywords=DC+breaker

Try to make the cable runs as short and direct as possible, within reason. The longer the cable run, the more resistance and the more voltage drop. All cables should be secured to the bulkhead with cable clamps in a neat, tidy, workmanlike fashion. If it's worth doing, it's worth doing correctly.

OLA is Open Lighting Architecture .. lets you convert one type to another .. but generally it has an ArtNet interface and lots of fun output interfaces including SPI. For some thoughts: last year I built 4 4'x8x16' steps we used on stage. We drove them with SPI Controllers .. that worked great .. but was expensive. The reason I went pi is the pi itself is $35 and built in wireless .. fadecandy is $22 .. can drive a pixel set of 64x8. This year we're building 12 steps 8'x8"x9" with 6 rows of 64 px driving off the QLC. I have githubs of the ansible code I use for all of this .. happy to share.

Some things to consider:

• PI - there is raspberry pi zero form factor .. which is quite small ;) I am experimenting with those now as full replacements for the Pi-B's and C's I have ( I used to teach with PIs so I have a bunch of em )
  
• interference - 802.11 can be impacted by bad dimmers .. things near by ( high amperag fryer, microwave), channel collisions with existing APs and most easily .. if it's visible lots of things will try to connect even with a password. Set your wifi to NOT broadcast the BSSID. And check the wifi spectrum when you get to a venue ;)
  
• amperage .. make sure you have enough to drive your px .. specifically something north of 80 px in a single strand you'll wanna inject power on the other end. The overall power supply doesn't have to be crazy .. but investing in a good volt-ohm-amp meter meter is worth it for testing and validation.
  
• universes .. I've successfully transmitted 4-6 U over a single SSID of 802.11bng . If each px is individually addressed .. and you're using RGB .. then each px is 3 DMX channels. Each U is 512 channels .. that gives you 170 px in a single U and QLC doesn't handle crossing U in a single fixture.. but does handle things with matrixes .. so you'll have to play around with the config and layout. You can always use the same channel(s) for multiple fixtures of the same type.
  
• road-rash .. touring with such a rig .. plan spares of everything and have a test program you can run to make sure it looks right. The LED strips don't handle LOTS of bending .. but some. The "Sticky" on the back is for shit. plan clear tape or something else to make sure they stay mounted whereever you're putting them. Also .. the "joining" kits you can to connect 2 strips work reasonably well .. BUT they dont' like to move alot. We've started soldering them on to the strips once we have the design set.
  
  Please feel free to reach out any time .. do lots of work in this space and always willing to help ;)

>I'm not sure an impedance sweep would work for me

Well, a REAL impedance sweep would work, but the voltage drop test wouldn't. You can get a clamp for a very little amount and use it to measure the AC amperage at the positive output on your amp. Hook your dmm up to the positive and negative amp outputs, play a single freq. record the volts and amp, play another freq. etc. Divide the numbers and here's your impedance curve. I think that information will be incredibly useful for you because it will remove a lot of the guesswork when you build and rebuild.

>how would that react with the front phase

In a transmission line, the front and back waves are in phase so it's all good. Here's an example. And another

> tapered t-line

Awesome, remember the more you taper the more bandwidth you gain and output you lose. Don't go over a 3:1 ratio. Here's an incredibly helpful table that will show you determine the length of the line: http://i.imgur.com/DA1zW0B.png

S0= cross-sectional area at the closed end, SL= cross-sectional area at the open end.
So, a 2:1 would be a .5 on his table. Source if you want to read it.

I've had one of these for years and it works pretty well, but it is unnecessarily big and clunky. Personally, I would go with this one instead. I bought it a little over a year ago and it has been a very good meter. I would honestly take it over pretty much any of the Ames meters we sell. If you need one with a current clamp on it, this one will probably do it for you. I don't have one personally, but Big Clive on YouTube does and he seems to like it.

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If you don't already have a meter, don't even bother getting the $4 one. I have a couple that I got with a free coupon and they are all junk. The leads are downright trash. The only time I use one is if I am doing current measurement and I don't want to risk blowing a fuse in one of my good meters.

It's easy enough to check :) Have fun on your trip. RV camping without facilities is a good skill to have under your belt. A camping group I'm in took our three RVs up to Rocky Mountain National Park. It was a great time and we were all nerding out about how much battery we had, etc because you have a pretty narrow charge window there. It really became useful when a 4th showed up with no generator and we were able to help them out because we knew exactly what our status was and what we needed to get through the night.

If you are a gadget guy, this can be a handy thing to have:

https://www.amazon.com/gp/product/B00O1Q2HOQ

What makes it different from other meters is it can show you DC current as well as AC just clamping over a wire. Most cheap meters only do AC current via the clamp and measuring DC current is more involved.
That can be SUPER handy for seeing how much power your batteries are taking in during the charge cycle or putting out during the discharge part of the day. The meter does other stuff too a multimeter would which is good to have in the field.

Dacă ai fast charge pe device-uri (adică un telefon modern, puternic sau o tabletă se încarcă în 1-2h), și nu ai cabluri normate la 2-2.5 amperi, ceva se va topi/mișca prin el. Idem dacă sunt niște chinezării care pot duce 5v, dar nu 9v. Trebuie să ții cont de cum le încarci. De exemplu, pe laptop/PC poți scoate cam 0.5A max, de pe încărcătoarele vechi 0.8-1A, și de pe încărcătoarele pentru telefoane moderne, cam 2-2.5A. Dacă schimbi modul de încărcare, de ex de pe charger pe laptop, e normal să se încarce mai lent

Ce pot păți cablurile (și nu prea le poți repara, pentru că sunt turnate):

1. Curgerea (deformarea plastică) a izolației dintre fire - în functie de fir, poate ajunge să apară ca rezistență între V+ și masă, adică o parte din energie va fi în scurt prin fir, o altă parte va ajunge în telefon. Cumva echivalent cu o rezistență electrică pe alimentare.
   
   
2. Fast-charge pe cabluri ieftine = căldură. Dacă simți că mufa dinspre telefon se încălzește când încarci, ori dezactivezi fast-charging, ori îți iei un cablu pe care scrie că e ok cu fast-charging (poate avea diferite denumiri: IQ, IQ+, IQ2, QuickCharge, etc) sau ăla de la producător. Dacă se încinge - ori topești izolația și scade rezistența între semnale (ie - pierzi din putere), ori se mișcă (foarte puțin) contactele între fir și mufă - gândește-te că le favorizezi o poziție si le tensionezi să stea așa, după ce se va răci.
   
   
3. Dacă ții telefonul de fir, scoți mufa din telefon scuturând firul și așteptând/aruncând telefonul sau "smucești" firul, dacă îl ții prin buzunar (de ex cu o baterie externă) sau îi faci noduri/bucle/etc e posibil să busești una sau ambele mufe: fie smulgi o parte din fire din contacte (daca un semnal e pe multifilar) - scăzând astfel puterea pe care ar putea-o livra, fie - din nou, faci izolația din interior să curgă.
   
   
4. Dacă viteza cu care se încarcă telefonul pe un cablu "folosit" + încărcător bun e egală cu viteza cu care se încarcă pe un cablu "bun" și port usb PC SIMPLU (nu e albastru, nu scrie high power pe el, sau are alte iconițe în afară de USB) ai o problemă foarte comună. Prima generație de smartphoneuri care au avut nevoie de putere mai mare decât aveai dintr-un port USB de PC/laptop au făcut mufe "de încărcare" și cabluri "de date"; mufa de încărcare punea în scurt semnalele de date (D+ și D-) astfel încât telefonul știa că nu e legat la un PC (un PC ar folosi semnalele de date, ca să poți să te "uiți" in telefon și să-l "vezi" în My Computer), dar un încărcător nu. Au apărut apoi cablurile "de încărcare" care aveau scurtul direct în ele, și mergeau cu orice fel de încărcatoare - dar nu mai mergeau să legi telefonul la PC. De multe ori însă, izolația pe D+/D- e foarte foarte nașpa, mult mai nașpa decât cea de pe firele "de alimentare" (V+ și GND), astfel încât se poate străpunge/face scurt cu altceva sau pur și simplu rămâne "în aer" (D+ nu mai e în scurt cu D-). Dacă se întâmplă asta, atunci telefonul vede că D+ nu mai e în scurt cu D-, și încarcă lent. Telefonul comută viteza de încărcare, ca să nu blocheze portul USB (dacă telefonul vrea mai multa putere decât îi permite portul USB de pe PC, PC-ul va considera că portul e în scurt-circuit și îl va bloca)
   
   Cum le poți repara?
   Nu prea poți.
   
   Cum le poți testa?
   Nu foarte ieftin. Fie cu o su]rsă de laborator, și cu câteva rezistențe (sau niște rezistențe decadice), fie cu niște jucării d-astea: sarcină și tester. Nu prea le poți testa înainte sa le cumperi
   
   Cum alegi cabluri și cum te comporți cu ele?
   În experiența mea, Anker și cele OEM.
   
   
5. Cu cât e mai lung, cu atât pierzi mai multă energie "pe drum" și ce încarci se încarcă mai lent.
   
   
6. Asta se întâmplă indiferent de material; când chiar contează, diferența de preț va fi mult mai mare (think: aliaj cu aur)
   
   2.5 Singurul caz in care poți avea cabluri și lungi și care încarcă rapidă e atunci când cablul e gros. Foarte gros. De exemplu cu tool-ul ăsta, pe 5V/2A și pierderi de 5% ai secțiune de cupru în cablu de 1.5mm^2 și pentru pierderi de 1%, ai secțiune de 5mm^2. Distanța între pinii din mufa USB micro e de 0.5-0.6mm. Ai nevoie de 4 fire d-astea într-un cablu
   
   
7. Nu brusca cablurile și nu le fă bucle. Dacă chiar trebuie să le faci bucle, nu mai mici de 8-10cm, și fixează bucla în 2-3 locuri cu "șoricei" sau panglică de cabluri.
   
   
8. Contează atât calitatea firelor, cât și a conectorilor.
   
   
9. Conectorii turnați sunt aproape mereu superiori celor cu carcasă de plastic care se asamblează (personal nu am găsit contraexemplu). Dacă mufa din cablul tau se "desface" în 2 piese de plastic, si vezi firele și mufa, atunci nu e turnat, e probabil lipit prin cu adeziv. Problema nu e neapărat asta, ci faptul că un chinez îți va lipi cablul de mufă, comparativ cu lipirea automată pe cablurile turnate. Suplimentar, mufele turnate "umplu" mufa cu material, astfel încât devin mai rezistente la smulgeri, îndoiri repetate, etc, și sarcina e preluată de fir, nu de mufă. Cum le deosebești: e turnată dacă e dintr-un material similar cu cauciucul la atingere, sau pe două laturi opuse, unde observi o linie - linia nu e în interior. Linia reprezintă planul unde se închid cele două părți ale matriței de injecție, și fie va fi o nuanță ușor diferită, fie va avea altă textură. Poate fi prin turnare și dacă nu are nici o linie vizibilă. Dacă linia respectivă e înăuntru, atunci e planul unde cele două piese ale mufei se închid - și mufa e din două piese.
   
   5.2 Excepția e lipirea prin ultrasonare când ai tot două piese, dar lipitura nu e prin adeziv, ci forțezi piesele să vibreze la frecvențe suficient de mari încât se topesc în punctul de contact și masele plastice se amestecă. Arată mult mai bine decât o mufă din două piese lipită cu adeziv, și lipitura nu se vede, ci pare că e dintr-o singură bucată.
   
   
10. Also, nu cumpăra cabluri prea ieftine. Dacă se încinge și ai sub cablu ceva ușor inflamabil, ai pus-o.

Battery could still be severely shorted but it sounds unlikely. If that were the case you would notice a very large spark when connecting the jumper cables and possibly see a reaction from the second car. Everyone should own a good multimeter, you can get pretty good ones in the $40 range, or crap ones for like $5 at harbor freight.

I'm thinking most likely warranty will come into play for you, but if it ends up being battery after all the dealer battery prices are surprisingly reasonable. So you could have it towed there if you want.

Edit: BTW, I like this Uni-T UT210E clamp meter for the price: https://www.amazon.com/Uni-T-B4Q094-UT210E-Current-Capacitance/dp/B00O1Q2HOQ.

For anything that plugs in, you can use a smart plug like this to track its energy usage. For anything hardwired, you could use a meter with a clamp like this to measure instantaneous current.

So with the plug, rotate it around the biggest appliances in the house. Keep the fridge plugged in for a day, see what the average draw is, etc.

But you are right that heating/cooling is likely to be the culprit. The clamp meter will help you gauge its impact. Despite how it seems though, a 1990's air conditioner isn't dramatically less efficient than a new one...assuming it's in good working order. Make sure the condenser outside is all clear, no leaves piled up against it, dirt clogging the fins, etc. Then inside, follow the ducts wherever you can to make sure nothing came disconnected and is dumping conditioned air into you attic or something.

If it helps as a point of reference, our 2,400 sf house has central air from the 80's that is set for 75 when we're home and 82 when we're not, and our power bill for the July-Aug cycle when we were using AC consistently was $104. We're in coastal New England/ag zone 6b.

Then as the other commenter mentioned, your power company may offer free energy consultations where they come test your house for efficiency in a variety of ways, give you free LED bulbs and programmable thermostats, and make recommendations for how to reduce energy use.

I keep a small bag in my main bag that I can clip to my belt. I mostly use it when I know I'm going to be working in a panel for a while but in general this covers 75% of my needs. Here's the bag.

Here is what I keep in it.

Wire Stripper / Needle Nose I haven't had these for too long but I really like them.

Small meter I like this one for a lot of reasons. One is that will fit in the bag and is good enough to use under 480 in my opinion.

Voltage Detector The meter has non-contact voltage detection, but I like this one more.

Crescent Wrench I like this one because it also has the monkey wrench on it so it's good for tightening air lines from time to time. Though in reality I don't use that feature much.

A couple larger screwdrivers #2 phillips and a flat head big enough to open panels easily.

Controls Screwdriver For terminals and such. I sometimes use the ones with the rotating end.

Flashlight These are not the best, but they're cheap and work as a penlight and they can do area illumination with a magnetic base.

I have seconds (and in the case of the meter and flashlights - a higher quality version) of all these in my main bag, but I mostly use this little pouch.

Things you should do now:

• Contact the power company. Someone may be stealing electricity from you. Your meter may be broken. Someone may have shifted a decimal place in your cost per kWh.
  
• Buy some kind of watt meter and check the appliances and electronics in your home to see what's using the most power.
  
• Get an energy audit. A lot of times your energy companies or your state/municipality will have free or discounted options for this available. Have someone come check what's using power, where your heating/cooling dollars are going, etc.
  
  Things to consider in the future:
  
  
• More insulation, especially in the attic. Walls and floor are helpful as well.
  
• Pressure test the house. This is something an energy audit company may do for you. Increase the pressure in the house using a large volume fan and use smoke to identify where your house is drafty. Fix the air leaks.
  
• Upgrade to a more efficient heating/cooling system. Heat pumps are all the rage these days. If you have electric heating, that's pretty much the least efficient way to go in terms of heating your house or your hot water (or cooking or drying clothes). Upgrade to heat pump or natural gas.
  
• Update your windows with low-E coated double-paned argon-filled glass. It sounds like you may have already done this. If your new windows didn't check all three boxes, consider getting your money back.
  
• Plant deciduous trees on the south side of your property. While not an immediate benefit, the leaves in the summer will help keep the sun off your house, keeping the cooling costs down. In the winter, the leaves fall off, letting the sun shine through and warm the house.
  
• Check for drafts on interior walls. If you have electrical or plumbing running through your interior walls, and the holes through your top and sill plates aren't properly sealed, you may have a draft of air moving from the basement/crawlspace up into the attic, making your interior wall effectively a cold radiator. Seal the gaps with spray foam to stop the drafts.
  
• Add a water heater blanket around your hot water heater. This will help keep more heat inside the water, so you spend less energy keeping the water hot in case it's needed. Better yet, upgrade to a tankless unit and only pay for hot water that you actually use.

I Love This Greenlee Drill/Tap set!

And of course my Wera Screwdriver Set. Makes dealing with terminals a breeze.

Everyone here seems to like Milwaukee power tools, but I have a Milwaukee drill/driver, but seriously, I prefer the 12V Bosch drill and impact driver. I was trying to use the brand new Milwaukee to drive a 1/4" lag bolt into my dock, and it stalled about 4 threads in. Grabbed the 8 year old Bosch, and drove it all 3 inches down without a sweat.

ETA: Something I only pull out once in a blue moon, but when I do need it, a good Fox and Hound is an absolute bloody necessity! I have that one for general wires, and my Fluke network test kit one for Coax/Copper Ethernet. I wish there was some way for someone to make one for fiber, but oh well, that's next generation physics.

I guess I should also say, the GreenLee Slug-Buster knockout set is amazing. No time spent trying to pop out slugs from the punches.

Oh, lord, I could go on...

Okay, one last one, sitting on my desk: a Brady printer. I can use that to print wire labels FAST (Real Fast), directly importing from a wire run list in a CSV format, but it also does legend plates, and pushbutton/switch plates. Godly.

Okay, I'm done.

No wait.. .One more, for instrumentation guys: Fluke 4-20mA Clamp on... LOVE IT

Okay, I'm really, REALLY Done

And every garage I've been in has 1 compact fluorescent bulb. Buy a nice LED shop light or 2 depending on how big your garage is. Buy all the tools you need to wire it in like a nice set of Klein strippers and a cheap multimeter.

https://www.amazon.com/gp/aw/d/B000F9HIEC/ref=mp_s_a_1_4?ie=UTF8&qid=1495670572&sr=8-4&pi=AC_SX236_SY340_FMwebp_QL65

https://www.amazon.com/gp/aw/d/B00NWGZ4XC/ref=mp_s_a_1_9?ie=UTF8&qid=1495670627&sr=8-9&pi=AC_SX236_SY340_FMwebp_QL65&keywords=Multimeter&dpPl=1&dpID=417YqOjJ1mL&ref=plSrch

Cheap multimeters are fine for things around the house or troubleshooting most things on cars. You can also use the clamp yo measure current draw for some more advanced troubleshooting like seeing how much your AC compressor is drawing. If you do lots of tinkering with electronics I'd recommend dropping a few hundred on a Fluke.

Sorry lots of electronics technical stuff I just spat out there... this video might help

https://www.youtube.com/watch?v=HWA9WqSEjg8

The issue is it's a bit of "chicken and egg" problem, you need a powerful enough supply (high enough amp output) to make sure the load has as many amps as it will draw if the power supply can't supply enough current then your current you measure will be that limit instead of what the device actually wants to draw. If the power supply isn't able to supply enough amps for a given load (a device drawing current like the raspi) then it may overheat or shut off to protect itself or switch on and off depending on the power supply design.

Regarding a bench power supply this video shows how to DIY and compares with bought version and shows how they work:

https://www.youtube.com/watch?v=wI-KYRdmx-E

Basically any multi-meter can measure voltage and amperage:
https://www.amazon.com/Etekcity-Multimeter-MSR-R500-Electronic-Multimeters/dp/B01N9QW620/

For higher current stuff or measuring AC current without hooking the meter physically into the circuit can use a clamp meter like this instead:
https://www.amazon.com/Etekcity-Multimeter-MSR-C600-Auto-Ranging-Multimeters/dp/B00NWGZ4XC/

^^ second one also does auto-ranging so it works out what the right unit is to show you is based on the power going through it (shows mV or V or A and mA or milli-ohms, ohms, kilo-ohms, and mega-ohms depending on what you're measuring)

A simpler video just covering the whole concept of "load" and current here too (youtube suggestions did a good job)
https://www.youtube.com/watch?v=cxkVxi9P0EA

Hi there, I have experienced something like this twice. If you are sure that everything is in order and there are no obvious billing errors, I strongly suggest you get a clamp ammeter like this:

https://www.amazon.com/Fluke-323-True-RMS-Clamp-Meter/dp/B00AQKIEXY/ref=sr_1_7?ie=UTF8&qid=1500148644&sr=8-7&keywords=power+meter+clamp

Power all circuits down in your house, switch everything off. Put the clamp over the inlet cable and see if there is power running through, if there is, something is broken or wrong, call an electrician. If not, then power each device or item up, one at a time and look for things that are drawing excessive electricity.

I had a beer fridge fail one day, but it did not die, the motor decided to run 24/7 somehow not freeze the beer, but just keep drawing. I've also dealt with a faulty fluorescent basalt that was drawing way more power than it should have been, even while seemingly working fine. In both cases, there was a sudden cost spike and my utilisation increased significantly.

Clamp meters allow you to measure the power without exposing the cables, so this is safest if you're not electrically savvy. I would also suggest a device like this:

https://www.amazon.com/Excelvan-Display-Voltage-Electricity-Monitor/dp/B00E1E1XA2/ref=sr_1_2?ie=UTF8&qid=1500148919&sr=8-2-spons&keywords=power+meter+plug&psc=1

You can use this occasionally to test and check equipment or appliances are not over drawing. Some of these plugs have the ability to state the cost of the electricity being used, a useful tool to gauge the cost of running or owning appliances.

Not sure what your definition of 'expensive' is. https://www.amazon.com/Extech-MA435T-400A-Clamp-Meter/dp/B00FF3X3AG/

There's plenty of cheaper ones that are probably fine safety wise (especially given you won't be working in switcboards or anything), but make sure it's able to measure low DC voltages. Lots only have one voltage range, which would be OK for mains work but not really where you care about the difference between 12 and 12.5V.

Dealer tech here,

First off, do you have any aftermarket remote start or alarm equipment installed in the vehicle?

All your volt testing looks like about what i'd expect.

I find the amp clamp somewhat suspicious. Subaru calls this "Dark Current" (also known as parasitic draw, dark draw, etc.) and ideally you should use a small-jaw clamp (i use this) that is considered "accurate" at sub-100 mA. Typically the large-jaw clamps are fine for 1A+ measurements but the resolution isn't great for lower amperages. In either case, you need to be damn sure the jaws are fully closed. I find the negative cable end easier to get the jaws around typically. You also need to zero the tool as close to the position the measurement would be in as possible - things like florescent lights can affect the readings. (My shop is full of florescent lights and turning my meter 90 degrees can throw it off by 60mA or more!)

That all being said, subaru's spec for dark current is 70mA or less. (They even published a bulletin about it, #07-85-14, which might be good for a read) so if you're confident that your measurement is accurate, then the likely culprit is the battery.

Also, all this testing and potentially a battery replacement is covered under your 3yr-36k mile warranty if you still have it.

I use a clamp meter but the kill-a-watt sounds like a cheaper, and awesome alternative.

A 117 is a pretty standard meter that will handle your basic measurements. Any of them will be safe for computer and automotive use if used properly. Dc clamp meters are handy for automotive. This one is pretty handy for catching smaller dc currents although the trade off is the jaws are small for larger cables such as those to the starter.

Great work! You've basically made a bombe calorimeter of sorts.

Your figures might be a little low because I don't see any mention of the mass of the light/battery. That is at least 85 grams of stuff also being heated with the 300 grams of water.

(The UT210E is a great cheap clamp meter for this.)

Instead of flipping each breaker for an hour, try this. Get a multimeter that tests amperage. Something like this:

https://www.amazon.com/dp/B00NWGZ4XC

You'll have to carefully remove the panel cover from your circuit breaker panel. Set the meter to amps and put the clamp around the black wire coming off each breaker. You'll be able to tell pretty quickly what circuit is using all the power, and you won't have to shut anything off.

I like this one. Measures down to milliamps. I've found quite a few of their products useful including the LoadPro.

Electronic Specialties 688 True RMS Low Current Clamp Meter https://www.amazon.com/dp/B00DGTOOLS/ref=cm_sw_r_other_awd_BedRwbF7ZSBPJ

Here's a perfect example: http://www.amazon.com/Fluke-Intrinsically-True-Rms-Multimeter-Temperature/dp/B00C2DVKPC/ref=sr_1_4?s=hi&ie=UTF8&qid=1453106210&sr=1-4&keywords=multimeter&refinements=p_36%3A80000-99999999

I guess these are not for home use? Perhaps Industrial?

I saw this one on Big Clive's YouTube channel and it's served me very well.

Uni-T B4Q094 UT210E True RMS AC/DC Current Mini Clamp M W Capacitance Tester https://www.amazon.com/dp/B00O1Q2HOQ/ref=cm_sw_r_cp_apap_SCHenkNd6Avzz

This is the clamp meter I have and it's awesome.

https://www.amazon.ca/Mastech-MS2115A-DIGITAL-Multimeter-Voltage/dp/B00KFLSXAI/ref=asc_df_B00KFLSXAI/?tag=googleshopc0c-20&linkCode=df0&hvadid=292939046378&hvpos=1o1&hvnetw=g&hvrand=16847363522585628214&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9060756&hvtargid=pla-494295494635&psc=1

I bought this one a year ago and I use it all the time, it's been great so far.

https://www.amazon.com/gp/aw/d/B00NWGZ4XC/ref=mp_s_a_1_3?ie=UTF8&qid=1500249073&sr=8-3&pi=AC_SX236_SY340_QL65&keywords=etekcity+multimeter&dpPl=1&dpID=417YqOjJ1mL&ref=plSrch

Since the things you have plugged in don't generally change a whole lot, you could use something like a [plug in energy meter] (https://www.amazon.com/TS-836A-Energy-Voltage-Electricity-Monitor/dp/B00E945SJG/) to measure those sorts of devices and a [clamp on amp meter] (https://www.amazon.com/Klein-Tools-CL200-Clamp-Temperature/dp/B003LDFVBG/) to measure the ones that don't. It is obviously not real time, but it'd be quite a bit cheaper than monitoring every circuit in real time. Once you know how much power your large appliances use, it isn't going to change. ;)

No. Double the budget and come back.

-----

servers draw Oh, I dunno 700W each typically, but can triple that under serious load.

A typical switch needs right around 200W.
A PoE switch needs 200W plus the PoE load.

I have no idea what "6-7 other network devices" means.

But lets be kind of safe and call them 300W each.

• Thats 2100W for servers.
  
• 900W for switches.
  
• 2100W for "other network devices".
  
• Lets add 1000W for things you forgot and/or surge capacity.
  
  Thats 6,100W of capacity using rough, approximate estimates.
  
  So for that base load you're looking at about an 8kVA UPS unit like this one:
  
  http://www.apc.com/shop/us/en/products/APC-Smart-UPS-SRT-8000VA-RM-208V/P-SRT8KRMXLT
  
  He will run for 8 minutes at 6000W of load.
  
  http://www.apc.com/products/runtime_for_extendedruntime.cfm
  
  So we will need some extra batteries.
  
  http://www.apc.com/products/runtimegraph/runtime_graph.cfm?base_sku=SRT8KRMXLT&chartSize=large
  
  You're looking at two extra runtime battery packs like this one:
  
  http://www.apc.com/shop/us/en/products/APC-Smart-UPS-SRT-192V-8-and-10kVA-RM-Battery-Pack/P-SRT192RMBP2?isCurrentSite=true
  
  -----
  
  So either:
  
  

1. Go find more money
   
2. Go find more accurate information on load requirements.
   

• A Clamp Meter is your friend: https://www.amazon.com/Etekcity-MSR-C600-Digital-Multimeter-Resistance/dp/B00NWGZ4XC
  
  
  Clamp that on a power cable, and it will tell you the amps passing through.
  it might tell you the voltage too, or you will need to take a reading from an unused outlet using the two included probes.
  
  Volts times Amps equals watts.
  
  Total Wattage demand determines UPS size.
  
  WARNING: devices use more power during boot-up than they do at idle.
  
  
  Personally, at this size, I'd start thinking about a small Symmetra Frame like this:
  
  http://www.apc.com/shop/us/en/products/APC-Symmetra-LX-8kVA-Scalable-to-16kVA-N-1-Rack-mount-208-240V/P-SYA8K16RMP
  
  Yeah, its more expensive.
  But it offers N+1 redundancy / high-availability, and it can scale up to 16kVA by adding power modules.
  
  

A nice fancy multimeter perhaps?

https://www.amazon.com/Fluke-323-True-RMS-Clamp-Meter/dp/B00AQKIEXY?ref_=ast_sto_dp

Anything like this, also referred to as a clamp meter:

Etekcity Digital Multimeter, MSR-C600 Auto-Ranging Clamp Meter https://www.amazon.com/dp/B00NWGZ4XC/ref=cm_sw_r_cp_apa_i_W9eQCb7BVGEM3

You run it over one half of a circuit to see the real time usage. For most devices you just grab one of those flat extension cords and carefully separate the insulated wires, or clamp it over the wires in the breaker box.

There's proper voltmeters that can test it better than just a pen. I got this one.

Etekcity Auto Ranging Clamp Meter, Digital Multimeter with Amp,Volt,Ohm,Diode and Resistance Test https://www.amazon.com/dp/B00NWGZ4XC/ref=cm_sw_r_cp_apa_i_NLKtDbMQ00KZ3

Where are you measuring the AC voltage, at the battery? Any ripple will read as AC voltage, 40millivolt ripple isn't much.

If you have a DC clamp meter, put that on the alternator cable and you can easily read if thats the cause. If you don't own one, they're handy and this ones nice for the price: link. Another option is to measure the other circuits in your car like this with a regular meter: https://www.youtube.com/watch?v=lRcj1fQcWwU

Unfortunately the alternator is the one thing that cant be measured this way since it doesn't go through the fuse box. But you can eliminate everything else this way.

I read the same warnings and had the same concerns about the sata cables. So I bought one of these: Uni-T B4Q094 UT210E True RMS AC/DC Current Mini Clamp M W Capacitance Tester https://www.amazon.com/dp/B00O1Q2HOQ and measured the current. Each of my GPUs pulls 0.3A from the sata connector, which is well within spec for sata.

Both from Amazon

YZXstudio 1270 meter, a XINY Load Tester Board and RIJER USB adapters

I did find this

https://www.amazon.com/dp/B001TCWL1E/ref=cm_sw_r_sms_c_api_KDy7ybCTN2SPC

Will probably buy them for the teams as it's just a general troubleshooting tool. Big $$$ savings when we are buying 20 of them!

Take the time to learn how to use a multi meter. It will help you for the rest of your life. Electricity and electronics should be taught in primary school and everyone should know how to use a multimeter. A multimeter is simply a combination various meters and testers into one device: a voltmeter to measure volts, ohmmeter to measure resistance in ohms, an ammeter to measure current in amps, and various other things like electrical connection continuity, temperature (with temp probes).

You can purchase a simple multimeter for less than $10, however for your specific electrical problems, I recommend one that has a DC clamp-on ammeter like this one. That lets you clamp the meter around a wire to measure how much current is flowing, like on brake light circuit to see if it's drawing the correct current needed for the light bulb, or whether there's a short circuit that's drawing a lot more current than it should be doing.

If you aren't willing to learn how to use a multimeter, then don't bother attempting to fix this problem by yourself. Find another mechanic. You need to know basic electronics to diagnose and fix most electrical problems, and it can be dangerous to you and to others for you to mess with electrical things without that knowledge.

Here are some links for you to read and learn from people that have gone before you....

Handy Bob, kind of grumpy but knows how to make solar work, will give you the basics. It is getting dated but a good place to start.

Voltage Drop Calculator,you need to know how much loss will be in the wires and compensate for it or else watts are just heating wires and not charging batteries.

A Multimeter so that you can troubleshoot and verify that your system is working.

Ohm's law, you should at least understand the concept and relationship between voltage, amperage, and watts. Watts are universal. a 1,000 watt device be it Ac or Dc is always 1,000 watts. But 1,000 watts at 12 VDC draws 84 amps (lots of current. AT 120 VAC 1,000 watts draws 8.4 amps. See the relationship there? Volts x amps = watts.

There is a link in the FAQ on the page for how to do this. If it's an AC device (plugs into a household wall), then the most accurate thing to do is buy a Kill-a-watt meter and actually measure it.

Most devices list their max power draw, either in watts or amps. If it's in watts, just plug that into the calculator. If it's in amps, we have the converter at the top of the page to get the watts. If you can't find the power listed on your device, but own the device, you can get an ammeter (like this one) and measure as it's being used.

So you just want a current meter?

[Fluke 323 True-RMS Clamp Meter ~$100 on amazon](
https://smile.amazon.com/dp/B00AQKIEXY/ref=cm_sw_r_cp_dp_T2_pTavzbJDCH1BV)

Tl/Dr: video of what i just wrote out (video is not mine as I would start at the wall first. I had that beaten into me as an apprentice)

first invest in an inexpensive meter. heres an auto ranging clamp meter

then test the outlet. going by this pic check Line to line it should be 240v then line to neutral and line to ground 120v on both lines. and ground to neutral 0v

if all is good with the outlet, meter the connection on the unit the same way
l

Most ovens are 240, regarding your want for a meter, go with a Fluke or a Fieldpiece.

Here are things from my wishlist (past and present)

Wera Screwdrivers
https://smile.amazon.com/dp/B0085NTQJK/

Oscillating blade set:
https://smile.amazon.com/dp/B0109SELWA/

Clamp multimeter:
https://smile.amazon.com/dp/B00NWGZ4XC/

Kreg Jig Jr.:
https://smile.amazon.com/dp/B000J43A7W/

Angled Long Nose Pliers:
https://smile.amazon.com/dp/B00N3VSS4S/

Groove Lock Pliers:
https://smile.amazon.com/dp/B000FK1R0W/

11 ft wifi endoscope:
https://smile.amazon.com/dp/B01MYTHWK4/

non contact voltage tester:
https://smile.amazon.com/dp/B001UAHZAM/

claw nail puller:
https://smile.amazon.com/dp/B0015YPJMY/

Workmate portable work bench:
https://smile.amazon.com/dp/B000077CQ0/

Cable snake fish tape:
https://smile.amazon.com/dp/B000BP7WBO/

9 Outlet metal power bar:
https://smile.amazon.com/dp/B00F8ZQY5M/

Spade drill bit set:
https://smile.amazon.com/dp/B00099E7WE/

36" bubble level:
https://smile.amazon.com/dp/B000UKMWMO/

Could probably figure it out for $35 and 15 minutes of your time.

https://www.amazon.com/dp/B005HOPRRK/ref=cm_sw_r_cp_apa_kmpIybT3YFPXY

What about this one? http://www.amazon.com/gp/product/B00AQKIEXY?psc=1&redirect=true&ref_=ox_sc_act_title_1&smid=ATVPDKIKX0DER

Check out a clamp meter. You would need to be able to get to the wiring near the breaker to measure the amp draw there.
https://www.amazon.com/dp/B00NWGZ4XC

There are also ones you can put between the outlet and item, but that only measures that item, not the whole load. It only works on 110v items (not an electric dryer).
https://www.amazon.com/P4400-Kill-Electricity-Usage-Monitor/dp/B00009MDBU

https://www.amazon.com/Amprobe-1000A-AC-Clamp-Meter/dp/B00U2F6RQ4

Multimeter

are you using one of these to measure?
https://www.amazon.com/Uni-T-B4Q094-UT210E-Current-Capacitance/dp/B00O1Q2HOQ/ref=sr_1_5?ie=UTF8&qid=1499406313&sr=8-5&keywords=current+clamp

This is the one I use:
http://www.amazon.com/Digital-Clamp-Meter-Uni-Trend-UT203/dp/B005HOPRRK

Some clamp meters are AC only. The clamp acts as a current transformer. This one is AC/DC, uses a Hall effect sensor. I need DC capability for automotive stuff.

Two options - use the kW rating on the name plate or buy a [clamp meter] ( http://www.amazon.com/Fluke-323-True-RMS-Clamp-Meter/dp/B00AQKIEXY) which goes completely around the wiring and measures how many amps you're actually using at that moment. Amps multiplied by voltage equals watts. Watts multiplied by 1,000 equals kilowatts.

Edit: learn2math.

http://www.amazon.ca/Fluke-365-Detachable-True-RMS-Clamp/dp/B004I2ZSLC

http://www.fluke.com/fluke/caen/clamp-meters/fluke-381.htm?pid=70413

This is the one I use. I only use it for current because i have a Fluke DMM, but that clamp meter has all the other functions of a DMM as well. They just aren't very accurate at low currents, compared to a regular meter.

It's simple to measure power draw if you have multi-meter and willing to cut open a short extension USB cable to measure current and voltage at the point near the sensors usb connector.

You can also use these devices, but they aren't as accurate.
https://www.amazon.com/Multimeter-YZXstudio-KAAYEE-Recognition-Resistance/dp/B01KTV9RHQ/ref=sr_1_8?ie=UTF8&qid=1485270055&sr=8-8&keywords=usb+power+meter

These circuits are located in event halls. The events are pretty small so we only risk the 20amp circuits but I like to think a few steps ahead to avoid power loss in the middle of a tournament.

The biggest issue is computers. Most of the lower end ones are not a problem but when you have 1k watt to 1.5k watt power supplies the amps add up quick. I figured if I was able to monitor the power I could proactively make sure we are not getting close to tripping circuits.

Do you know if meters such as this work accurately? Do you think it would work for what I am trying to do even if I have to manually go up to it and test it? https://www.amazon.com/Fluke-323-True-RMS-Clamp-Meter/dp/B00AQKIEXY/

As am/ have I.
I carry this one on my back at work

http://www.amazon.com/IDEAL-61-746-Clamp-Pro-Clamp-Meter/dp/B001Q92VVU

However like I said I use my Klien M1000 at home when overclocking, Its spot dead nuts accurate .

Yeah you even said that you changed it... My bad.

To the onboard diagnostics, there is no real difference between a magic box (sensor) and the magic pathway going to it. What kind of line goes to the sensor? Is it just a regular wire? Coax type line? Something else fancy? Do you have a multimeter? If so can you disconnect both ends and check resistance (ohms) through the wire?