Yesterday I passed SFS6002 electrical safety course and got SFS 6002 käytännössä book. SFS 6002 electrical safety training is for all electrical work in Finland engaged in compulsory education, which must be renewed every five years. Now I know somewhat more than before on electrical safety related to electrical installations.
SFS6002 is a Finnish standard how electrical work should be performed safely. It is based on European general standard EN 50110-1 (Operation of electrical installations – Part 1: General requirements) plus Finnish national additions to it.
If you want to get your hands on the original European EN 50110-1 standard, you need to buy it. There are also free information on standard available: British edition of the standard BS EN 50110-1:2004 can be found on-line.
760 Comments
Tomi Engdahl says:
Understanding European and Scandinavian plugs and sockets
https://toughleads.co.uk/pages/european-sockets
Tomi Engdahl says:
Standards
https://xkcd.com/927/
Tomi Engdahl says:
Testing The Burn Ability Of Insulation In Wall
https://www.youtube.com/watch?v=CdItsso3ur0
The majority of spray foam using your house would have a fireproofing additive and would have trouble Catching Fire but in this example is if you have a type without the additive such as the great stuff. A vapor barrier is very important in a wall so just the rockwool batt insulation it’s more commonly used for an attic floor not a wall. Fiberglass proved to be pretty safe in the test but if you’re worried they make fiberglass with a aluminum radiant / vapor barrier. They do make fire retardant spray foam but it’s usually for commercial application but I don’t see why you couldn’t pay that company to put it in your house but you’re going to pay. They make fire retardant paint especially for spray foam which I personally can’t see it working very well since the heat of the fire will cause the foam to melt behind it leading to the collapse of the paint exposing it to Fire and on the other hand it’s most likely the firewood start behind the Paint as a slow smolder first in the wall
Tomi Engdahl says:
Fuse replacement meme
https://www.memedroid.com/memes/detail/2798221/Guide-to-fuse-replacement
Tomi Engdahl says:
Switches are Clicky; Here’s Why
https://www.youtube.com/watch?v=jrMiqEkSk48
“Everything conducts electricity if you try hard enough” as an electrician, can confirm LMAO
EShine says:
Thanks for sharing this precious information with us.
Tomi Engdahl says:
Finding HIGH POWER 240V in a 120V Country
https://www.youtube.com/watch?v=OiwWaIvIeao
Traveling around and need a power adapter to run your 240V hair drier? GOOD LUCK!
OK BOOMers!!! I’m sure a bunch of you will be traveling these holidays. May I suggest… LEAVE YOUR $%#@ing HAIR DRIER BEHIND?!!!
HAPPY HOLIDAYS!!
Tomi Engdahl says:
Portable Mains Kit from Aldi
https://www.youtube.com/watch?v=70LhBdwQQL8
A mains distribution box for use at campsites. 16A plug connects to site electrical system. Box has a miniature consumer unit with MCB and RCD, neon indicator, three 13A outlets and two USB sockets.
Video comments:
Flex undersized and probably the wrong type for use outdoors, the most useless type AC RCD, world’s cheapest components, defective instructions, inconsistent info (13A or 16A), and all intended for use in a high risk outdoor environment.
Nothing good there.
Tomi Engdahl says:
Poliisin epäilee somehaasteen vieneen tytön junan katolle – siellä odotti 25 000 voltin sähköjännite https://www.is.fi/tampereen-seutu/art-2000008240088.html
Tomi Engdahl says:
https://come4concepts.com/types-of-insulators/
Tomi Engdahl says:
LED shock hazards are increasing
https://www.youtube.com/watch?v=FeKL82V3p-Q
I’m getting more messages from people who are receiving shocks from faulty LED lights – especially flood lights.
The problem is caused by internal arcing that occurs in LEDs when they are part of large series strings being driven by high voltage supplies. When the LED fails open circuit it starts to arc and track internally, often causing flickering of the light in the process.
Because the aluminium substrate LED panels have an extremely thin layer of insulation between the copper and aluminium, it is easy to damage it when an LED burns up, especially the newer directly mounted flip-chip LEDs. This results in a conductive path to the aluminium, which may not be grounded.
The thin layer of insulation also causes unusual effects when people touch ungrounded LED lights with the switch on the neutral, and the LEDs glow because the person touching the ungrounded light provides a ground path for capacitively coupled current from the LED panel.
With the high number of improperly grounded LED floodlights coming into the country via direct import or from distributors who have not tested their imported products properly, the risk of shock from outdoor lights (and some indoor lights) is increasing. This introduces a few secondary hazards. A metal fence or structure that the light is mounted to may become live, any shock from a light at height could result in a fall and the effects of rectified DC current leakage may affect the ability of some RCD/GFCI devices to trip, and may also prevent tripping when AC leakage occurs from another fault/shock.
I’d recommend that extra precautions are taken to fully isolate faulty metal cased LED lights before working on them, and if there is any doubt about the power source then insulated gloves should be worn and work should only be done in dry weather.
I’d also recommend that the ground integrity of lights is properly tested, and lights with flimsy copper coated aluminium flex have it replaced with something more appropriate if possible.
It’s best to source new lights from prominent suppliers in your country that have a reputation to uphold. That automatically excludes most eBay and amazon sellers.
Tomi Engdahl says:
How to Find the Number of Outlets on a Single Circuit Breaker?
https://www.electricaltechnology.org/2021/09/number-of-outlets-on-breaker.html
How Many Outlets Can You Put on a Single Circuit Breaker? – NEC & IEC
The most frequently asked and searched question from home owners and DIY dudes is what is the exact number of outlets, receptacles and sockets which can be installed on 15A or 20A circuit breakers. While electrical engineers and electricians know the answer based on calculations and experience, let’s share the same rocket science information with you.
Before going in detail, keep in mind that NEC (National Electric Code) doesn’t mention the exact number of outlets per circuit breaker. It only suggests that only 80% of load can be connect on a rated circuit breaker i.e. the load should not exceed the limit of 80% e.g. a 15A circuit breaker can only be used for 12A load points (15A x 80% = 12 A)
This way, based on a rule of thumb, a total of 8-10 numbers of outlets (rated for 1.5A) can be installed on a single pole, single phase 15A, 120V circuit breaker.
Ideally, a 15A, 120V single pole breaker will handle electric load about 1800W. But the National Electric Code doesn’t recognize it. The NEC suggests that 80% (0.8 of the breaker rating) of load can be put on a circuit breaker
Power = 1800W x 0.8 = 1440 Watts
Now, the total number of outlets can be determined by dividing the power wattage by supply voltage.
Number of Outlets = 1440 Watts / 120V
Max Number of Outlets = 12
To be on a very safe side to avoid unnecessary tripping of the breaker, you may again multiply the calculated number of outlets with 0.8. e.g.
Safe Number of Outlets = 12 x 0.8 = 9.6
This number fulfills the basic rule of thumb for finding the number of receptacles which is 1.5 amperes per outlet. In short, the safest numbers of outlets are 8-10 per circuit breaker rated for 15A, 120V, 1-P.
Example 2: 230V – IEC – UK & EU etc
To find the number of outlets in areas where the supply single phase voltage is 230V. You will have to divide the calculated wattage rating of the breaker by 230V.
Power = 230V x 10A = 2300 Watts
2300 W x 80% = 1840 W
Now divide by the supply voltage of 230V to calculate the total number of outlets.
2392 W / 230V = 8
It means, you can install a total and max 8 numbers of outlets on a 10A, 230V single phase MCB circuit breaker.
Method 3 – When the Wattage Rating of Outlet is Known
Example:
How many outlets each of 80W can I put on a 20A, 120V circuit breaker?
Power Wattage = 120V x 20A = 2400 Watts
Apply the safe limit of a breaker which is 80%.
2400 Watts x 0.8 = 1920 W.
Now, divide the wattage rating of the breaker by the wattage rating of the outlet.
Max Number of Outlets = 1920 W / 80W = 24
Tomi Engdahl says:
How to Wire a UK 3-Pin Socket Outlet? Wiring a BS1363 Socket
https://www.electricaltechnology.org/2021/05/wiring-3-pin-socket-outlet.html
Tomi Engdahl says:
How to Determine the Right Number of Lights on a Single Circuit Breaker?
Step By Step Guide: https://tinyurl.com/vja8aw6u
Tomi Engdahl says:
Glowing power line
https://youtu.be/8Skm4X3WFMM
Tomi Engdahl says:
https://www.cbsnews.com/news/parents-warn-about-electric-shock-drowning-after-15-year-old-girls-tragic-death/
Every day, about 10 people in the U.S. die from accidental drowning, according to the Centers for Disease Control and Prevention. But electric shock drownings are difficult to track. It’s known as a “silent killer.”
Even a low level of electric current in the water can be extremely hazardous or fatal to a swimmer — especially in freshwater, where experts say the voltage will “take a shortcut” through the human body.
“There is no visible warning or way to tell if water surrounding a boat, marina or dock is energized or within seconds will become energized with fatal levels of electricity,” the non-profit Electric Shock Drowning Prevention Association reports.
In fact, Johnson says, he never would have known what happened to his daughter if he hadn’t felt the electric current himself while trying to jump in to save her.
Johnson later found a light switch at the dock that was half full of water. When he put the metal ladder into the water, the electrical current from the light switch traveled through the dock to the ladder and into the surrounding water, where the girls were swimming.
Electrocution water
https://youtu.be/dcrY59nGxBg
Tomi Engdahl says:
https://www.electricaltechnology.org/2021/09/voltage-potential-transformer.html
Tomi Engdahl says:
https://en.m.wikipedia.org/wiki/Electrical_injury
Tomi Engdahl says:
https://www.electrocuted.com/safety/statistics/
Tomi Engdahl says:
https://www.ecmweb.com/maintenance-repair-operations/article/20898683/dont-discount-the-danger-of-120v
Tomi Engdahl says:
https://www.ecmweb.com/content/article/20885660/the-case-of-the-120v-electrocution-mystery
Tomi Engdahl says:
Rebeka Fox
Ordinary, household, 120 volts AC electricity is dangerous and it can kill you if goes through you.
Electrical injuries affect more than 30,000 people a year in the United States and result in about 1,000 deaths.
https://en.m.wikipedia.org/wiki/Electrical_injury
Electrical hazards cause more than 300 deaths and 4,000 injuries each year among the U.S. workforce.
https://www.electrocuted.com/safety/statistics/
working in proximity to live 120V circuits leads to the untimely and unexpected death of many workers each year
https://www.ecmweb.com/content/article/20885660/the-case-of-the-120v-electrocution-mystery
Tomi Engdahl says:
my circuit design principles other to keep DIY circuit and other electronics safe around be:
- ground fault protected electrical outlets with ground
- when making DIY circuit you know you need to play with, design it preferably so that it uses a commercial safe external power supply
- when need to play with live circuit on lab, have safety isolation transformers
- when designing directly mains powered circuits, prefer to built them to grounded metal case (in/out connectors grounded to case) or completely inside an insulating plastic case (with no connections out)
- when building ungrounded equipment with connections out, use plastic case and dual insulated rated power supply/transformer
Tomi Engdahl says:
https://hackaday.com/2021/09/17/retrotechtacular-the-dangers-of-confined-spaces/
Tomi Engdahl says:
Live Wires on Your TONGUE?! Making Arcs with ARCS?? (LATITY-007)
https://www.youtube.com/watch?v=KVjHwrKJg8k
Tomi Engdahl says:
How To Repair Damaged Romex Wires
https://www.youtube.com/watch?v=GhTb891mD6E
TE Romex Splice Kit: https://amzn.to/3DVclxP
Wago 221 2-pin Lever Nuts: https://amzn.to/38NLfu9
Damaged romex with exposed wires is a safety hazard and is something you want to take care of at the time of the damage. I will demonstrate 2 different ways to fix this issue which should cover the variety of situations you could encounter depending on where the damage occurs. First, we will install a junction (handy) box and splice the wires with Wago 221 lever nuts in the newly installed box. Next, we will show how to install a TE Romex Splic Kit which is a great solution when the damage occurs in a wall cavity or another location you can’t install a handy box.
Tomi Engdahl says:
https://www.dieselvoima.fi/alumiinikumikaapelit-nain-muutat-alumiinin-kullaksi/?utm_source=facebook&utm_medium=cpc&utm_campaign=alumiinikumikaapelit_artikkeli
Tomi Engdahl says:
How to Determine the Suitable Size of Inverter for Home Appliances?
https://www.electricaltechnology.org/2021/09/sizing-inverter.html
Tomi Engdahl says:
Comparison of UPS Topologies: Line-interactive vs Online vs Offline
https://community.fs.com/blog/line-interactive-vs-online-vs-offline-ups.html
Tomi Engdahl says:
Difference Between Current Transformer & Potential Transformer
https://www.electricaltechnology.org/2021/09/difference-between-current-voltage-potential-transformer.html
Tomi Engdahl says:
Meme
https://me.me/i/key-cleaner-i-need-to-clean-some-keys-5882532
Tomi Engdahl says:
Repairing Underground Power Cables Is Nearly Impossible
https://www.youtube.com/watch?v=z-wQnWUhX5Y
In 1989, this story about an underground electrical transmission line spread across the early internet like wildfire. It had a big impact on me as a kid, and I wanted to share it with you! I think the Scattergood-Olympic transmission line is probably LA’s most famous power line, although it has now been replaced with a more modern line since 2018.
Tomi Engdahl says:
LED shock hazards are increasing
https://www.youtube.com/watch?v=FeKL82V3p-Q
I’m getting more messages from people who are receiving shocks from faulty LED lights – especially flood lights.
The problem is caused by internal arcing that occurs in LEDs when they are part of large series strings being driven by high voltage supplies. When the LED fails open circuit it starts to arc and track internally, often causing flickering of the light in the process.
Because the aluminium substrate LED panels have an extremely thin layer of insulation between the copper and aluminium, it is easy to damage it when an LED burns up, especially the newer directly mounted flip-chip LEDs. This results in a conductive path to the aluminium, which may not be grounded.
The thin layer of insulation also causes unusual effects when people touch ungrounded LED lights with the switch on the neutral, and the LEDs glow because the person touching the ungrounded light provides a ground path for capacitively coupled current from the LED panel.
With the high number of improperly grounded LED floodlights coming into the country via direct import or from distributors who have not tested their imported products properly, the risk of shock from outdoor lights (and some indoor lights) is increasing. This introduces a few secondary hazards. A metal fence or structure that the light is mounted to may become live, any shock from a light at height could result in a fall and the effects of rectified DC current leakage may affect the ability of some RCD/GFCI devices to trip, and may also prevent tripping when AC leakage occurs from another fault/shock.
Tomi Engdahl says:
https://stek.fi/sahkoturvallisuus/sallitut-sahkotyot/liitanta-ja-jatkojohtojen-korjaus/
Jos sähkölaitteen liitäntäjohdon pistotulppa on vahingoittunut, voidaan se vaihtaa uuteen.
https://stek.fi/sahkoturvallisuus/sallitut-sahkotyot/jatkojohtojen-teko-ja-korjaus/
Käytännössä uusia jatkojohtoja ei kannata tehdä, koska tarvittavat osat maksavat enemmän kuin valmis jatkojohto. Tämän on useimmiten myös turvallisin vaihtoehto. Jos kuitenkin pitkä jatkojohto menee poikki, voi siihen lisätä pistotulpan ja pistorasian ja saada kaksi käyttökelpoista jatkojohtoa. Samoin voi vaihtaa rikkoutuneen pistotulpan tai jatkopistorasian tilalle uuden seuraavien ohjeiden mukaan.
Tomi Engdahl says:
https://foorumi.hifiharrastajat.org/index.php?threads/virtakaapelit-genelec.111631/page-3
Mikähän on “huippuvirtajohtojen” kustannusrakenne? Kate 60%, markkinointi 25%, työvoima 13% ja materiaali 2%?? Tämä siis ihan hihasta. Mutta turha on DIY-miehiä ylenkatsoa. Siinä jos missä säästää, jos on taitoa ja löytää parhaat raaka-aineet ja komponentit.
Datasheetin mukaa 8020B imaisee täydellä volalla maksimissaan 50VA. Eipä siinä 0,75mm2 piuha vielä kuumene. Netin mukaan liitosjohdot on yleensä 6A tai 10A speksattuja. Yhden piuhan päähän kestäis laittaa n 20 kaiutinta speksien mukaan… Jostain muusta on kyse.
Tomi Engdahl says:
http://www.mattikaki.fi/~w125312/sahkoturvallisuus/
Tomi Engdahl says:
https://electronics.stackexchange.com/questions/26232/electrocution-in-rubber-swimming-pool
https://imgflip.com/memetemplate/64086799/Electric-pool
Tomi Engdahl says:
Hyvin tehty sähkösuunnitelma on tärkeä osa rakennuksen toimivuutta — katso sähkösuunnitelmien toteutuneita hintoja täältä
https://www.iltalehti.fi/asumisartikkelit/a/d5179257-2bfe-4ff6-a893-818caaeb1066
Tomi Engdahl says:
Melted extension cord example
https://m.facebook.com/groups/avdisasters/permalink/4135790193216127/
Tomi Engdahl says:
Repairing Underground Power Cables
https://hackaday.com/2021/10/05/repairing-underground-power-cables/
Tomi Engdahl says:
Soldering when done properly works on mains cables, but it needs to be done properly and there are possibilities for mistakes.
The strength of a copper conductor, especially stranded, is reduced by soldering, as some of the diameter of the copper changes from copper to a copper tin alloy. Solder and wire with solder can be very brittle and can crack and break if you try to flex it.
Also solder if not properly done can melt under fault conditions.
Tomi Engdahl says:
https://martencables.co.uk/product-category/connectors/power/iec/
Tomi Engdahl says:
A Guide to making an in-line, wire to wire connections.
http://nicab.co.uk/guide-making-line-wire-wire-connections/
Tomi Engdahl says:
Minun käsittääkseni verkkovirralla toimivien laitteiden valmistukseen ja myyntiin ei yllättäen tarvitse mitään muodollisia pätevyyksiä. Kuka vaan saa niitä tehdä kunhan testaa, dokumentoi ja merkitsee ne pienjännitedirektiivin mukaisesti. Sähkölaitteiden korjaukseen taas vaaditaan muodollinen pätevyys S3.
Tomi Engdahl says:
Minun käsittääkseni verkkovirralla toimivien laitteiden valmistukseen ja myyntiin ei yllättäen tarvitse mitään muodollisia pätevyyksiä. Kuka vaan saa niitä tehdä kunhan testaa, dokumentoi ja merkitsee ne pienjännitedirektiivin mukaisesti. Sähkölaitteiden korjaukseen taas vaaditaan muodollinen pätevyys S3.
Tomi Engdahl says:
Minun käsittääkseni verkkovirralla toimivien laitteiden valmistukseen ja myyntiin ei yllättäen tarvitse mitään muodollisia pätevyyksiä. Kuka vaan saa niitä tehdä kunhan testaa, dokumentoi ja merkitsee ne pienjännitedirektiivin mukaisesti. Sähkölaitteiden korjaukseen taas vaaditaan muodollinen pätevyys S3.
Tomi Engdahl says:
https://tukes.fi/tuotteet-ja-palvelut/sahkolaitteet/sahkolaitteiden-vaatimuksia/sahkoturvallisuus-lvd
Tomi Engdahl says:
https://en.m.wikipedia.org/wiki/Schuko
Tomi Engdahl says:
look at the regular plug and socket used in Germany. It’s grounded and it has three contacts but you can insert it at 0° or 180°. Same or similar design is used in many European countries.
Tomi Engdahl says:
Wago blocks
https://youtu.be/OI5ddnK_3-8