In addition to providing computing, data storage and AI services, the new data center will the the World’s Largest District Heat Recovery Scheme. Excess heat produced by the datacenter servers will be captured and routed into the local district heating network serving Espoo, Kirkkonummi, and Kauniainen. The system is set to cover 40% of the annual heating needs for roughly 250,000 households. Reusing this heat is projected to eliminate 400,000 metric tons of CO₂ emissions annually by displacing fossil fuel usage because the power for data center is sourced entirely from renewable energy.

Construction at Hepokorpi has progressed steadily through phases of ground preparation, rock excavation, and steel frame erection, and some of the first building are already built.

The data center needs a lots of power. While Microsoft does not publicly disclose precise, operational server power capacity figures for individual datacenter halls, official environmental impact assessments and project plans provide clear technical estimates: Estimated Electrical Capacity (IT & Infrastructure Load): Up to ~100 MW (with environmental impact assessments for the broader site evaluating total capacity scales around 100 MW to 200 MW across various expansion phases). For this reason the data center seems to be connected to a big new transformer connected to 400 kV power line. That would mean up to almost 300A current taken from 400 kV three phase power line.

It looks the voltage is dropped to 110 kV level that is then sent to the data center buildings, although. Fingrid’s newly built main Hepokorpi primary transmission substation actually steps down the 400 kV grid power to 110 kV using compact Gas-Insulated Switchgear (GIS) technology. From there, regional sub-transmission lines and Caruna’s local distribution network route that 110 kV into Microsoft’s on-site transformers. On-site step-down transformers convert 110 kV to 20 kV (a standard medium-voltage level used in Nordic industrial facilities and distribution networks) that is most probably routed around the campus with medium voltage cables.

There it would be dropped with another transformer to the voltage level used by the data center computers. While Microsoft keeps precise proprietary server supply specs confidential, these follow standard OCP / Open Compute Project hyperscale architectures): Dry-type transformers step the 20 kV down to 400 V 3-phase AC line-to-line (230 V AC line-to-neutral). This feeds the Uninterruptible Power Supply (UPS) units and Power Distribution Units (PDUs). In Europe typical primary operational voltage feeding the rack server power supplies is 400 V / 230 V AC (3-phase 400 V AC input, delivering 230 V AC per phase). Server rack Power Supply Units (PSUs) convert 230/400 V AC directly down to 48 V DC distributed along the rack busbars. Modern high-density AI nodes (e.g., NVIDIA MGX/DGX racks used in Microsoft Azure AI clusters) rely on 48 V DC (lower losses than legacy 12V systems).

Microsoft’s Finland data-center project demonstrates how computing infrastructure can become part of a city’s heating system. Microsoft says waste heat (roughly 100 MW to 175 MW) from its Finnish data centers will eventually provide heat for around 250,000 people through district heating networks serving Espoo, Kauniainen and Kirkkonummi. The system uses heat pumps to raise the temperature of heat recovered from the data-center cooling system before it is transferred into the municipal heating network. I suspect that this building to be part of the heat pump system.

The recovery system requires infrastructure and energy — but that waste heat which would otherwise be rejected can be put to productive use. This approach could become increasingly valuable in colder regions where district heating is already widespread. Microsoft says the system is scheduled to begin operations in 2027. Combined with Microsoft’s sister facility in Kirkkonummi (Kolabacken), the joint campus footprint accounts for up to 350 MW of total thermal heat recovery for Fortum’s regional district heating grid.

Many other travel adapters only work well with ungrounded loads (typically either accept only ungrounded plug or leave ground not connected). This is one rare product that seems to handle grounding properly.

It supports many outlet types to schuko conversion. Just turn to right position – output makes contact with one plug on one side of adapter.

Pros: Universal adapter for many uses. One of the rare with proper grounding. It feels to be solid and well built. When turning the selector, power is cut before ground and connected before power. This worked well as promised.

Cons: I did not see fuse in uk adapter (would be a good idea to have 13A fuse in UK, fuse  not needed in other countries). The power source selection can turn quite easily – can turn accidentally and cut your power  output if you are moving cables. Two times more expensive than the ungrounded model.

What is inside this device and how it works. Here are some pictures to describe that.

This basic circuit published at https://www.facebook.com/share/p/1Gi4UZHpVh/ claims to be able to serve as an instantaneous way for you to detect whether it is in fact due to a blown fuse or not. It is a small circuit that tries to make your job as an electronic technician easier.

When the fuse is in working order the LED remains “off.” When the fuse has blown, however the LED lights up to provide you with an obvious notification of the blown fuse condition. Therefore, you do not need to guess or waste time continually re-checking the same device as this simple idea can save so much troubleshooting time and effort when working with power supplies or batteries.

#innovation #learning #electronicproject #simplecircuit

Could this build in a simpler way?
Why not simplify the circuit by wiring the LED directly across the fuse ( with a current limiting resistor )

Source: https://theorycircuit.com/electronics-projects/blown-fuse-indicator/

The downside of his idea:
1. When fuse blows, there is no reliable full isolation of load because of the current through LED
2. If load is removed, LED does not indicate blown fuse

Another way it so place a power indicator across the supply after the fuse. It works by showing if power gets through the fuse or not. The downside is that the indicator LED will consume power all the time when power is on.

Links to other ideas:
https://dmohankumar.wordpress.com/2015/10/21/blown-fuse-indicators-simple-design-10/
https://www.eevblog.com/forum/projects/blown-fuse-indicator-design-validation-automotive/
https://electronicsarea.com/blown-fuse-indicator-circuit-using-one-transistor/
https://theorycircuit.com/electronics-projects/blown-fuse-indicator/
https://www.edn.com/simple-blown-fuse-indicator-sounds-an-alarm/

Picture source: Facebook https://www.facebook.com/share/p/1DrRjhJH2r/

I have been reached that If you should not use a knot for cable strain relief.
⚠️ Important: If this is a 230 V / mains-powered device, proper mechanical strain relief is mandatory for safety and compliance.
A knot is not a safe strain-relief method, especially for electrical cables.
If this is for mains power, lab equipment, or a commercial product, knots are simply not acceptable.

Here’s why it’s considered unsafe ❌:
Uncontrolled bending radius → damages conductors over time
Stress concentrates at one point instead of being spread out
Insulation can be crushed or cut, especially on flexible cords
Not compliant with electrical standards (IEC, UL, etc.)
In mains voltage, a pulled knot can still transfer force to terminals
Proper strain relief must mechanically clamp or grip the outer jacket of the cable and transfer pulling force to the enclosure, not the conductors.

✅ Safe alternatives:
Cable gland (PG/M thread, rubber compression)
Strain-relief bushing / grommet
Screw-mounted cable clamp
Zip tie + fixed anchor (inside enclosure, jacket only)

Here is an analysis of each method:

1. Cable Gland (PG/M thread, rubber compression)

This is one of the most professional, secure, and robust methods for cable entry and strain relief.

How it works safely: A cable gland consists of a threaded body, a rubber or neoprene compression seal (grommet), and a compression nut. As you tighten the nut, the seal compresses radially around the cable’s outer jacket. This action creates both a strong mechanical grip for strain relief and a watertight/dust-tight seal (often rated to IP68).

Best Practices for Safety:

Correct Sizing: It is crucial to select a gland whose sealing range matches the exact outside diameter of your cable. A loose gland offers no protection, while an undersized one can damage the cable jacket.

Proper Tightening: Follow the manufacturer’s torque specifications. Under-tightening can lead to cable slippage, while over-tightening can crush the cable’s internal insulation.

Material Selection: Choose the right gland material for the environment. Plastic (nylon) is common for general indoor/outdoor use, while metal (brass, stainless steel) is preferred for industrial or hazardous locations for added durability and electromagnetic compatibility (EMC).

2. Strain-Relief Bushing / Grommet

These are commonly used in consumer electronics and appliances for a cost-effective and reliable solution.

How it works safely:

Strain-Relief Bushing: This is typically a two-part nylon component that clamps onto the cable and then snaps into a pre-punched hole in the enclosure wall. The geometric shape of the bushing, once snapped in, prevents it from being pulled back through the hole, effectively anchoring the cable.

Grommet: A simple rubber grommet protects the cable from chafing against the sharp edges of a metal hole. While it provides some friction, it is not a primary strain relief device on its own. However, some “strain-relief grommets” are designed with an internal membrane that grips the cable.

Best Practices for Safety:

Match to Cable and Hole: You must use a bushing designed specifically for the cable’s profile (round or flat) and dimensions, as well as the panel hole size and thickness. A poor fit will result in failure.

Installation Tool: For high-volume applications, a special assembly tool is often recommended to ensure the bushing is fully and correctly compressed and seated without damaging the cable.

3. Screw-Mounted Cable Clamp (P-Clip / Saddle Clamp)

This is a simple, mechanical method widely used in automotive, industrial, and general wiring applications.

How it works safely: A metal or plastic clamp, shaped like the letter “P” or a U-saddle, is placed over the cable and secured to a fixed surface inside the enclosure with a screw. The clamp holds the cable jacket firmly against the surface, preventing movement.

Best Practices for Safety:

Correct Size: The internal diameter of the clamp must match the cable diameter closely. A clamp that is too large will not grip, and one that is too small will pinch and damage the cable.

Cushioning: For metal clamps, choose a version with a rubber or vinyl cushion lining. This protects the cable jacket from abrasion and distributes the clamping force more evenly, preventing damage to the internal conductors.

Secure Anchoring: Ensure the screw is fastened securely into a solid part of the enclosure so the anchor point itself does not fail under tension.

4. Zip Tie + Fixed Anchor (Inside enclosure, jacket only)

This is a versatile and common method, especially for retrofitting or custom wiring, but it requires careful execution to be safe.

How it works safely: A zip tie (cable tie) is used to bundle the cable to a fixed anchor point inside the enclosure. The anchor can be an adhesive-backed mount, a screw-mount base, or a dedicated tie-down point molded into the enclosure.

Best Practices for Safety:

Grip the Jacket Only: The most critical rule is to only secure the outer jacket of the cable. Never place a zip tie around the individual insulated conductors after the jacket has been stripped. This can crush the insulation and cause a short circuit.

Do Not Over-Tighten: Tighten the zip tie by hand just enough to prevent the cable from sliding. Using a tool to over-tighten can easily crush the cable’s internal structure, leading to long-term failure.

Use Correct Anchors: Adhesive anchors can fail over time, especially in warm environments. For a permanent and safe solution, use a screw-mounted anchor base secured to the enclosure wall.

Anchor Location: Place the anchor as close as possible to the point where the individual wires break out of the jacket to minimize movement at the terminations.

Examples:
This YouTube video, it’s a great visual guide on how to properly install a cable gland, which is one of the most secure methods
Strain Relief Connectors… New design for more flexibility


Type Common Countries Nominal Voltage Grounded
A USA, Canada, Mexico, Japan 100–127 V No
B USA, Canada, Mexico 100–127 V Yes
C Europe, South America, Asia 220–240 V No
D India, Nepal 220–240 V No
E France, Belgium, Poland 220–240 V Yes
F Germany, Finland, Spain, Russia 220–240 V Yes
G UK, Ireland, Malaysia 220–240 V Yes
H Israel 230 V Yes
I Australia, New Zealand, China 220–240 V Yes
J Switzerland, Liechtenstein 220–240 V Yes
K Denmark 220–240 V Yes
L Italy, Chile 220–240 V Yes
M South Africa, Swaziland, Lesotho 220–240 V Yes
N Brazil 100–240 V Yes
O Thailand 220 V Yes


https://www.iec.ch/world-plugs

The ANENG B16 Induction (Tester) Pen—a compact is pen-shaped NCV (non-contact voltage) tester with some features of a multimeter.

Key Features & Specs:

• NCV AC Voltage Detection (Non-Contact): Detects AC voltage between 12 V and 300 V, suitable for everyday wiring, sockets, light fixtures, and low-voltage circuits. By simply bringing the pen close to a wire, users can identify voltage without direct contact. Equipped with both sound and light alarm features, the tester pen alerts you immediately upon detecting voltage
• Contact AC voltage measurement: By bringing the in contact with a wire energized metal parts, users can measure the voltage on the wire.
• Live/Neutral Wire Identification: Helps you distinguish between the live (hot) and neutral wires.
• Breakpoint/Continuity Tracing: Useful to trace a cable and locate where a wire is broken—indicator fades at the break point.
• Works in dark: LCD with Backlight provides clear readout of detected voltage and remains visible in dim lighting. Built-In Flashlight is handy for illuminating dark junction boxes or cramped spaces.
• Sound & Light Alarm: Alerts you via both buzzer sound and visual cues when voltage is detected.
• Slotted Screwdriver Tip: The steel pointed tip doubles as a flathead driver—combine testing and minor adjustments in one tool. It can be used screw in and repair electrical appliances in task that do not need a lot of force.
• Auto Power-Off: Powers down after roughly 3 minutes of inactivity to conserve battery.
• Safety: CE CAT II 1000V / CAT IV 600V according to documentation that come with the instrument.
• Dimensions: ANENG B16 is built ABS plastic body with total length of around 166 mm and maximum diameter of around 28 mm.
• Weight: The instrument wights around 60g total when batteries are installed to it. There is a pen clip on the back of the ANENG B16 Voltmeter tester.
• Power Source: Runs on two AAA batteries

AC Voltage Range: NCV Non-contact 20~1000V and contact 0~300V
Frequency 50/60Hz
Alarm Method Sound and Light Alarm
Flashlight White LED Lighting Fixture
Use Battery 1.5V AAA battery X2
Product Size 160×28.5×26.3mm
Product Weight 60g with batteries installed

Package Included:
1 x ANENG B16 Digital Tester Pen
1 x User Manual
1 x Packing Box

The ANENG B16 is a compact, budget-friendly tester pen ideal for quick checks to ensure a wire or socket is live. Its LCD, flashlight, and built-in screwdriver make it versatile for light-duty tasks.

The Aneng B16 is advertised as an intelligent induction test pen, not a traditional multimeter. It primarily measures AC voltage, identifying live and neutral lines, and can locate circuit breakpoints. It also features Non-Contact Voltage (NCV) detection for identifying live objects and a flashlight.

The B16 is best for quick, on-the-fly checks—like verifying that a circuit is live. The non-contact induction detection system that ensures no direct contact with live wires is necessary. You can also it to use to measure the mains voltage on wires, which can be useful compared to simpler non contact testers, but don’t rely on it for precision readings. In best cases it gives quite accurate results, but there are many things that can cause measurement errors.

Non-contact 12-300V AC measurement is somewhat misleading description. To measure voltages, I would not say B16 is true contactless instruments. To get voltage readings, the tip of the B16 needs to touch the voltage being measured and user needs to touch reference on the instrument. The user needs to ensure that during use your fingers maintain full contact with the touch reference point on the pen to maintain decent accuracy. The manual recommends to avoid contact with other metal or being near strong electric fields as this may skew results.

Digital Measurement of Voltage:
1. After booting up, select the number mode with the selection key, and the screen will display “0V”
2. Touch the touch pole with your fingers and use a probe to contact the AC charged body
3. Display the value of contact voltage on the screen (0-300V)

When using it, you need to keep in mind its limitations—it’s not a precision instrument and should be a preliminary tool rather than the only test used for important electrical work.

I was first a little bit worried on the safety, because you needs to touch the live circuit with the meter tip and touch the metal reference point on the meter that the same time. It can be a little bit frightening to trust just some cheap chinese electronics between potentially lethal voltage and your finger. The meter advertises CE CAT II 1000V CAT IV 600V ratings, which should mean safe enough for electrical working. I also took a look inside to be sure, and the construction looks OK. More on that later.

The meter is available from Temu, Banggood and AliExpress.

The meter is designed to measure AC voltage range 12V~300V. Select the voltage measurement mode,the screen displays ~V,touch the touch pole of the electric pen with your hand,and insert the electric pen into the socket for identification. The voltage measurement mode can be used to detect the live and neutral on the mains outlet. Touching the live wire should show around the mains voltage and touching the neutral side is expected to show zero volts or low voltage reading.

The LCD screen comes with a backlight when it is turned on, and the values on the screen can be clearly seen in a dark environment, and the readings are easy. The meter has also a built-in LED lamp that shines to the direction the meter tip points to. The screen is well-lit, making it easy to read even in low-light conditions. Additionally, the audible alarm alerts you to the presence of voltage.

ANENG B16 intelligent induction test pen AC voltage range 12V~300V,measuring circuit breakpoints

ANENG B16 Digital Tester Pen 12V-300V Non-Contact Voltage Detection LCD Display Sound Review

Attention: During the testing process, the fingers must be in full contact with the touch pole piece. The AC voltage measurement must be in contact with a live conductor in order to obtain accurate values. If it comes into contact with metal objects or the outer skin of charged conductors covered by an electric field, or if it is non-contact in a super strong electric field, although the voltage value will also be displayed, this value is for reference only and cannot be used as an accurate measurement basis.

Here is a look inside:

In this last picture you can see several high resistance high voltage resistors from the measurement tip to the measurement circuit input. The ground side of the electronics is directly connected to the touchable reference point on the side of the B16. The insulation distances on the circuit seem to be good where they are needed.

I did a measurement of the input resistance and insulation with an insulation resistance meter. I got reading of around 176 megaohms with 500V DC measurement voltage.

The ANENG B16 Digital Tester Pen was advertised as an impressive tool that seamlessly combines functionality with user-friendliness. Designed for voltage detection, it operates within a range of 12V to 300V, making it suitable for a variety of household and professional electrical tasks.

At the best is is a very handy tool. Being at same price range as many simpler non-contact voltage testers, it offers excellent value for money because of more features built in.

There are also downsides. The construction feels somewhat cheap and not high quality. The voltage measurement has limitation that it easily can measure very inaccurately. AC Voltage measurements are not accurate, but it’s not a meter. For quick checking it’s often enough.

Source: https://www.facebook.com/share/p/1HuYVvXHcf/

What is wrong with this design:
No isolation from mains, potentially electrocutes if you touch any part of exposed LED strip.
The circuit will only give around 220V/30000ohms=0.00766.. mA current that can light one normal LED but not any long LED strip like shown in picture.
Most of the power (over 90%) taken by the circuit will end to be power loss on the resistors (0.75W for each resistor) so they will run quite hot.
If you disconnect the LED strip from the circuit, the capacitor will be fried sooner or later.

The huge power outage on Monday brought large parts of the Iberian peninsula to a standstill, grounding planes, halting public transport, and leaving the two countries scrambling to restore power to millions of homes and businesses.
Widespread outage hits transport and communication networks with buildings plunged into darkness across swathes of the Iberian peninsula. Madrid’s Barajas International Airport and Lisbon’s Humberto Delgado were closed after being left without power, and telecommunications have also been affected, including no access to mobile networks and many stores and taxis in Madrid were no longer accepting electronic payments. Also other airports have come to a standstill and many flights have been canceled. Numerous passengers have also been left stranded in the metro systems of the Spanish and Portuguese capitals, with trains stuck in tunnels between stations. A blackout brought much of Spain and Portugal to a standstill Monday, halting subway and railway trains, cutting phone service and shutting down traffic lights and ATMs for millions of people across the Iberian Peninsula.

Major events, including tennis’ Madrid Open, were also affected. Several Spanish oil refineries were shut down and some retail businesses closed. Many workers were forced to leave their posts in Spain and Portugal on Monday after a major power cut affected phone lines, internet access, card payments, and left citizens without light. Essentially, the Spanish economy is shut down for the day.

Restoring power takes time

Several countries in Europe have been scrambling to restore electricity after a huge power cut caused blackouts. By Monday afternoon, Red Eléctrica stated that it had begun gradually restoring power in both the north and south of Spain. Spanish power distributor Red Eléctrica said that restoring power fully to the country and neighboring Portugal could take 6-10 hours. Sánchez thanked the governments of France and Morocco, where energy was being pulled from to restore power to north and southern Spain. REN said that the full restoration of the country’s electricity grid could take up to a week, but that it was “impossible” to tell for sure.

What caused the problem?

The cause is yet unclear. No “definitive reasons” have been found for a major power outage. There is no conclusive information on what caused the power outage that has affected Spain, Portugal and parts of France. Endesa and Iberdrola, Spain’s two major electricity providers, continue to investigate the incident. “Such a widespread grid failure is extremely unusual and could be caused by a number of things: there could be a physical fault in the grid which brings down power, a coordinated cyber attack could be behind it, or a dramatic imbalance between demand and supply has tipped the grid system over the edge,” Taco Engelaar, managing director at energy infrastructure experts Neara told Euronews. Today lots of these systems are connected and share assets – taking down one could take down many.

Reports indicate issues with the European electric grid. Spain’s Prime Minister Pedro Sánchez said that a problem in the European grid that he described as a “strong oscillation” was behind the outage, but that the cause was still being determined.

A fire in the south-west of France, on the Alaric mountain, which damaged a high-voltage power line between Perpignan and eastern Narbonne, has also been identified as a possible cause. Reports on a rare atmospheric phenomenon which have also been circulating have been denied by REN.

Meanwhile, the Spanish National Intelligence Centre has not ruled out the possibility of a cyberattack, while the Portuguese government has also suggested the same. On the other hand The Portuguese National Cybersecurity Center issued a statement saying there was no sign the outage was due to a cyberattack. “no evidence has yet been identified that points to a cyberattack” In the backdrop of unsubstantiated rumours flying around social media, the European Council said there were no indications the power outage was caused by a cyber attack.

The European Commission issued a statement on Monday afternoon, saying it was “in contact with the national authorities of Spain and Portugal as well as (European electricity transmission system operators’ network) ENTSO-E to understand the underlying cause and the impact of the situation.”

The EU has identified building up its power grid as an essential, and somewhat neglected, element in its efforts to move away from fossil fuels and cut energy bills – but it is also waking up to the need to prepare for attacks by hostile powers.

Live update pages:
https://edition.cnn.com/world/live-news/power-outages-blackout-spain-portugal-04-28-25/index.html
https://www.bbc.com/news/live/c9wpq8xrvd9t

Sources:

https://apnews.com/article/spain-portugal-power-outage-electricity-b0c5fbca49b8422248c4f933e20303b3

https://www.euronews.com/my-europe/2025/04/28/spain-portugal-and-parts-of-france-hit-by-massive-power-outage

https://www.euronews.com/my-europe/2025/03/27/europe-prepares-for-attacks-on-power-grid-while-battling-soaring-energy-prices

https://edition.cnn.com/world/live-news/power-outages-blackout-spain-portugal-04-28-25/index.html

https://www.theguardian.com/business/2025/apr/28/spain-and-portugal-power-outage-cause-cyber-attack-electricity

https://uk.news.yahoo.com/live/spain-portugal-power-outage-live-updates-113612434.html

https://www.iltalehti.fi/ulkomaat/a/c38b4db7-a2c7-43ca-8ee8-ce4587bac995

Finnish authorities board a ship in the Baltic Sea that the West suspects is linked to Russia, a day after an underwater Finland-Estonia electricity cable was cut and several telecom fiber optic cables were damaged.

Lloyd’s List on-line magazine claims that Russia-linked cable-cutting tanker seized by Finland ‘was loaded with spying equipment’

The incident has intensified fears in Europe over a Russian hybrid war targeting critical infrastructure in the Baltic and beyond. Estonia navy to protect undersea power link after main cable damaged.

Sources:
https://www.lloydslist.com/LL1151955/Russia-linked-cable-cutting-tanker-seized-by-Finland-was-loaded-with-spying-equipment
https://www.nytimes.com/2024/12/26/world/europe/finland-estonia-cables-russia.html
https://www.theguardian.com/world/2024/dec/25/finland-estonia-power-cable-hit-in-latest-baltic-sea-incident
https://yle.fi/a/74-20133531
https://www.bbc.com/news/articles/c1elq7lx9qdo
https://www.aljazeera.com/news/2024/12/27/did-a-russian-shadow-ship-cut-the-finland-estonia-undersea-baltic-cable

Source: https://www.facebook.com/share/p/GaGBsVVgdbYLfRW8/

It used to be a cable. Now it’s modern art.

That’s why it is recommended to always fully unspool/uncoil power cables before plugging in. It is a good idea to never leave cable on the drum when doing events..

You’d be surprised how many people don’t realise that can and does happen, even with a quite small load.
There are usually two power ratings on the cable nameplate, one for the rolled-up cable and one for the unrolled cable.
The rating for coiled cable is just a fraction of the unrolled cable rating.

Because people for reason or another do not always unroll the cable, for safety you should use cable spools that have a built-in overheating protector that cuts power when the coiled wire starts to get hot. Those overheating protectors are common in extension cable coils in Europe.

Here is one over heating protected coil example. The red one is resettable overheating tripping device that can be reset (like breakers).

Here is another example:

Let’s suspect the cable can handle 16A not coiled without problems. The safe rating when coiled might be only be 4A. If you try to push 16A through coiled cable it will melt sooner or later. I think 8A will make it already very hot
The long-term allowable operating temperature of cables: PVC insulation is 70°C

More information on the coiled cables in my earlier post https://www.epanorama.net/blog/2021/10/29/coiled-mains-cable-heating-and-inductance/