Re: Should this be so easy?
Yes. It's a proper rabbit-warren of rules and regulations.
I'm always happier with permanently-fixed cables and moulded-on plugs for appliances.
267 publicly visible posts • joined 11 Apr 2018
The connector is rated for a maximum continuous current and a maximum voltage.
The cable should be rated for the fuse that is fitted, the temperature of the environment and the conditions of installation.
The fuse is rated to the device it is protecting.
Changing the fuse doesn't uprate the cable, but the cable might be over-rated.
Using the wrong cable is naughty and can have disastrous consequences.
There are regulations for this sort of thing. Boring, not easy to grasp but if followed, lead to safe connections.
I'm not one to laud Portable-Appliance Testing but you find a lot of stunning incompetence.
It's always worth standing back a bit when using a multimeter. Our 240V AC on 50 Hz is the RMS voltage, so the peak is rather higher...... Also, if you are not sure of the source or if it is a supply from an inverter the waveform is non-sinusoidal and many (cheap) meters won't register the correct RMS voltage anyway. If you can get an oscilloscope-type observation you learn to be very respectful of 'live' or 'dead' connections.
Silly thing to do. I can't be the only person who could never use a multi-meter on an incorrect setting....... If only.....
Yesterday, I tried to measure the voltage on a small battery and wondered why it got rather hot. Fortunately, no-one was watching so it didn't happen.
I was mis-diagnosed as a genius because I could open documents which others thought were 'corrupted'. I used WordPad, saved the file to a different format and basked in the praise and honours. They thought I had access to a non-disclosed 'special text editor' despite using their own hardware/software to sort it.
In my early days, our Supervisor was in charge of Goods Inward and used chronological filing. Everything was placed in a pile on his desk; nothing was passed on, like Delivery Notes, Invoices, messages.... He was forever on the phone promising "I'll see to it."
We were forbidden to touch anything. Until he went on holiday, whereupon our suppliers would telephone me or visit saying "Please can we have our invoices paid?" Me and my colleague would then unpack his desk-top and over the next few days, sort and distribute the paperwork accordingly. There would be a sudden hit to the finance department but as they had gone several weeks or months without paying any supplier in the blissful state of 'not receiving the paperwork' and things were offered without tea-stains, spilt food, grease, dead spiders etc. they were grateful.
When the supervisor returned, to a clean desk, he pretended he had sorted everything before he went away. Eventually, I became his boss and took all paperwork away from him. We diverted his (desk) phone so he could not receive calls. He was good at his practical job so worth retaining, but I welcomed the end of the working week ---->
I used one of those chairs when I had 'a bad back'..... Physiotherapist said to try it. I was very sceptical. At work, I felt I was being laughed at. It took some getting used to but my back got better and I bought one for home as well. Expensive, as I had to change the floor covering from carpet to something tougher.
One of the other ways to relieve pain ----->
Oh you've triggered a real memory-storm.....
The old P&B Golds relays: Thermal and magnetic protection. A masterpiece of manufacture, construction and setting for superb machine protection. Superseded by programmable devices these days. Setting these relays was an exercise in job satisfaction.
We had to test a machine driven by a large motor supplied via diesel-generator. The motor-absorbed current when running was a bit less than the 600-A rating of the breaker but the starting current/time were too high/long to prevent a (correct) trip despite judicious adjustment of the 'settings'. These breakers are only designed for a small number of trips on high current so it wasn't something we could 'experiment' with for long.
My older, wiser, bolder, colleague suggested we reduce the set-speed of the engine, set the AVR (automatic voltage-regulator) low and on manual control, connect and close the circuit-breaker (operating it from an external supply) and start the engine, alternator and motor all together when the loads, voltages and currents would be much reduced. We could then bring the whole set up to full speed within the trip parameters.... It needed good coordination between us and was a bit scary initially, but it worked..... To be fair, we did ask the genset supplier for his thoughts which were initially unprintable but their engineer was curious, pliable, interested and eventually persuaded. He came to see the procedure but stood well to one side with his hands firmly in his pockets.
We used this procedure a few times until inverter-drives became more available making the process routine by comparison. We would not be able to do this with modern gensets.
We had to put a large standby generator into an old building which had no inside lifting capability. The genset, container-sized and weighing about 20 tonnes, was off-loaded by a crane into the doorway of the building and we were to 'skate' the set into position. It's a fit-once activity, normally, not too difficult with machine-skates, rollers, levers, pullers and wedges.
"Exactly as the Egyptians" said one educated young wag on our small team.
"No it bloody isn't" replied Wally, long in the tooth and short on words.
"Why's that, Mr Walter, Sir."
"They had a thousand slaves to 'elp them."
Well, we earned the refreshment at the end of the exercise. ------>
Having worked on power-electrics your adage rings so true.
"Is it switched off?"
"Is it isolated?"
"Is it earthed?"
"Can it be back-fed?"
No. No. No. Yes.
I was so paranoid about this, if I was isolating something for someone else, I demonstrated it was safe by putting my hands on the busbars. A tip gained from a North Sea Oil worker.
Despite the icon, I don't think that is a joke. There's many a true word said in jest......
When stating something that quotes 'facts' or 'sources' it is important that those references are listed so you can/could make your own verification/interpretation.
Not providing background makes an article 'opinion' and should be labelled as such.
We already know AI can make up lies.
I worked on a site involving a requirement to measure the flow in a river. This involved ultra-sonic senders/detectors at various heights in a section of the river and required a survey of the profile to get the placing correct. The contractor produced a very detailed plan of how they were going to measure the profile by a precise procedure involving personnel on both sides of the river. The river was tidal so timing was important and an emergency, rescue-boat would be made available on the day. The banks of the river were duly cleared of undergrowth and a clear path created together with tethers for life-lines. Each member of the team was briefed and it was clear that the squad were well-prepared. The river level had to be within certain limits and the weather forecast clear, with no rain in the previous week.
On the agreed day the process was again discussed, agreed and questions resolved. Everyone was happy. PPE was extensive and verified; each 'doer' had a 'minder'.
Well, the first thing they brought out was an inflatable boat and a paddle....
"Hang on. There's no boat in the procedure."
"We thought it would be easier."
The process was abandoned as they re-wrote the procedure to include a boat, its launching and recovery. Which then had to be agreed by all involved.
I have been through Schipol several times on business. It is the only airport where something has gone wrong on every trip. Lost bags, late-landing: missed connection, cancelled connection, connection impossible due to distance between gates.
Ridiculing my experiences and warning, my son took a flight via Schipol on his way to a wedding in Croatia. His bag never arrived. On a return trip from Sri Lanka, his delayed flight incited a number of German passengers to remonstrate and he lingered on their periphery to gain the benefits of their group action. He still missed his onward flight on reaching Schipol.
We had the same situation where the open-plan office had windows on three sides with lots of dappled light filtering in through the trees on the outskirts of the plot..... This light severely interfered with viewing on the CAD terminals and being an open-plan office with no real barriers, the sunshine caused a lot of irritation, especially between autumn and spring. Adjustable blinds were forbidden (mostly by the 'senior' wallahs who occupied the best locations which had a view...).
Now draughtsmen/women are very clever and artistic...... They created light-barriers on delicate, hanging threads, so they seemed to just perch in mid air. Carefully placed for optimum shielding at various times of day they used to wave gently as people walked between groups. I always thought it resembled a bazaar. But it was bizarre.....
We had a contract involving high-performance machinery on an application requiring high availability. Big project updating (very) old equipment with modern and lots of automation: involving a change in manning levels for operators and their maintenance crews.
During the transition from old to new, the equipment kept suffering unexpected trips and shut-downs often at inconvenient times including weekends. In order to get a handle on what was going on, we put detailed logging equipment on the instrumentation with a remote-access PC where I could dial in and observe recent historical data. We could then attend site with knowledge and reset things accordingly. No real reason for the trips was identified until 'secret' logging of the 'Hand/Auto' control switch was included. All the trips were associated with operation under (unnecessary) 'Hand' control. Unsurprisingly, when the operators became aware of this phenomenon the problems disappeared.
After a long, uninterrupted period of correct operation we removed the logging equipment but I left an old laptop installed to give the illusion of 'supervision'. It had a note and screensaver saying not to update the W95 operating system.
Some years ago, we went to a friend's party where at the end of the evening, a bottle of white wine remained unopened. It appealed to nobody's taste and was left. Some weeks later, I find this bottle of wine in our fridge....... Saying nothing, we smuggled it into another person's house, hidden in plain sight. Eventually, it must have been noticed; it had gone but lo and behold it was back at the first party's house, again there but not where expected.
These shenanigans went on for some time, the bottle had to be placed unobserved but not hidden completely.
I don't know how the saga ended, but now I'm thinking I ought to check our house.
Our boss inadvertently filled his (company) car with the wrong fuel. He tried to keep it secret but we were too clever for that. We were also impish so he didn't know that we knew.....
Smallish office and it was my turn to make the teas and coffee. The boss always had coffee.....
I 'inadvertently' made him a cup of hot chocolate and when he stepped out of his office to query the mistake I replied: "Oh no! I haven't poured the wrong drink have I?"
His eyes rose towards the ceiling as he realised he had fallen for the ruse and the resultant laughter all round only served to compound his embarrassment. He was a good sport and although he threatened a reprisal he became very wary of stepping into another trap. But that's another story.
I was brought up using metric and imperial units. School exercise books had the esoteric list including gills and bushels. Over a period of about twenty years, exams used both systems (including CGS & MKS: those who know, know....). US mils, barrels, gallons, pints and tons were always a potential source of error, not to mention slugs, as was the annoying habit of our friends over the channel of using odd metric versions (daN anyone? It's nearly a kilogram-force....).
In traditional engineering, I found some calculations easier using imperial units but overall I would always use metric. Although I still know metals by their UTS in tons/sq-inch..... And of course their En numbers which were introduced during WWII and still in use 40/50 years later.
In this fine forum, I often think that the editors pander to US units or spelling because they assume that USians are incapable of converting any unit or word into their common usage. But Europeans don't have this difficulty. Personally, I think the author should decide......
Anyway, lets agree on something ------->
Our small office also housed our manager's secretary who was a well-known bitter battleaxe. She had many good reasons for being bitter and we did not make fun of her unfortunate romantic history.
Office procedures involved quite a lot of internal mail, with envelopes re-used but sealed with staples. Being relatively new to the office, I asked the secretary to obtain a staple-remover to improve the status of my finger-nails.
About a week later, still without the requested device, I noticed the secretary using a very new staple-remover. On querying this anomaly she replied "The Stationery Department only had two, so I got one for Eric (the boss) and I've kept the other." End of conversation.
A few days later, I 'borrowed' the boss's staple-remover and altered its appearance to avoid detection. He never noticed. Nor did 'Rita'.
Trivial but these successes add up ------>
A 100-year-old company making specialist, rotating machinery for a wide variety of industries, including equipment for the armed forces, especially the Navy during WWI &II. As trainees, later in the same century, we used to get sent all over the factory to find old records and files etc. It was interesting in its own way and you developed techniques to retrieve information from long ago. The records were all paper or perhaps micro-fiche. One such repository was underneath an old building which I found out had been reinforced during WWII. The basement had been significantly extended, used as an air-raid shelter and the roof as an observation post. It was deep, dark, dusty and musty in places. In my wanderings in this dungeon, behind some old bookshelves, I found an old doorway into a small room which had clearly been out of use for decades. Curious, I moved the shelving...... and opened the door..... An old light-switch powered a single bulb to reveal a small desk and chair with a single telephone: vintage rotary type with twisted cord to the handset. You will have seen these in old wartime films.... On lifting the handset, it gave a dial-tone but I was too nervous and junior to try a call. I imagined it was a direct line to Biggin Hill....
I reported this information to our switchboard (three telephonists; it was a long time ago), then the bosses..... "It could be associated with the confidential/secret nature of some of our business." I was instructed to leave it alone. No-one else went to see it; "Urghh! It's dirty down there."
The building was demolished twenty years ago but it wouldn't surprise me if underneath the new housing estate, sometimes there is a ghostly ringing sound from a room that was built over.
Your comment about a cleaning lady/man rang a distant bell..... When we were ejected from the old company and set up on our own, we were successful and eventually decided we could employ cleaners rather than an unenthusiastic rota.
The consortium that got the contract, to clean about five offices, reception, toilets and kitchen etc. comprised some ex-employees from the old company. One of them was a super-highly skilled machinist; his task had been typically to machine 8-m long crankshafts for large diesel engines on a bespoke lathe. These forgings were very expensive before they reached the machining stage. Not to belittle cleaners but it felt such a waste of talent/skill to take him on as a cleaner. He took the contract with good grace and did a good job until we were taken over and the accountants appointed a different set of cleaners; it will surprise no-one that this lot were slightly cheaper and much less competent.
For all those who deserve better ---->
I was asked by a colleague to assist when he received a contractual letter from his phone-supplier. He had a Nokia 6310. The only contact he could make was by phoning their help-line. Unfortunately, he was deaf and he could see how this was going to pan out. So I phoned up, using his phone and after going through multiple 'security checks' I was able to discuss the issue on his behalf. When I explained that the actual owner of the phone was deaf they were dumbfounded:
"Why does he have a phone then?"
"Er... Text messaging?"
"Oh! Of course! Well we'll reduce his contract price, then." Really not the outcome we were expecting.
When we were taken over, the new owners expected to make major 'buying gains' due to their vastly bigger turnover and spending. I was sent to one of our usual suppliers to discuss the new arrangements and how it was anticipated that we would now get the 50% discount of the holding company. Over a good lunch (I had worked with this suppler for years) the MD explained that we received a bigger discount than our new owners because "You pay on time" whereas "They don't. Ever".
I went back to explain that the expected buying gain might actually be an increase in price.
Soon after we were taken over, accounts were run by Head-Office off our site. Accounts decided that all terms of payment would be doubled, so the 30-day payment terms to our suppliers became 60 days, if they were lucky. This is a standard accounting wheeze, well known by El Reg commenteers.....
Our progress-chaser was a determined lady whom it was unwise to cross, and when she found out that our usual supplies of toilet paper for the offices and factory had been withheld by our supplier, pending payment of previous month's accounts, she phoned up our head-office chief accountant who was unsympathetic and unhelpful.
In response, she explained: "I'm on my way to your office and I am going to piss on your desk." Two minutes later a return call advised that payment had been made and deliveries happened the next day.
I went to commission some large machinery for a waterworks, drawing water from a river for treatment. All the important people were there, including the end-user and his consultants. All went well and the consultants remarked how good their concept had been, hardly using any energy. I went to have a look at the electricity meters which indeed were turning much slower than expected. A gentle 'tap' on the side of the meter sent them spinning away at a more likely rate; much to the embarrassment of the consultant and dismay by the end-user/payer......
"I wish you hadn't done that."
Further percussion did not revert the rate. Good job for us though ---->
When we were bought out by a bigger concern, a TLA. We had to use their systems for manufacturing, buying and accounting. This was a step-backwards to green-screen command-line procedures. The new bosses were very good at asking other people to provide information from this system but were unable to obtain it themselves. We called them AWDUTS: Ars***** Who Don't Use The System.
I've said before that we used our old and their new systems to show how everything they bought was over-expensive, thus exposing corruption. But no good deed goes unpunished and I was eventually made redundant..... In retrospect, a great outcome. So ---->
We commissioned a large set of equipment at a big water-treatment works. Big job, full day so we started very early and I had a plan for breakfast on-site as they had a good kitchen. I had a student/trainee with me who was keen to help and we set him off to buy the necessary foodstuffs from the local shop. There were four people in our team.
He returned with ten packs of bacon, four packs of butter, eggs galore and a bread-van load equivalent. A few fishes and we could have fed the region. We started cooking our well-deserved breakfast.....the aroma was unmistakable. It was surprising how many of the site staff 'were just passing by' and helped themselves to a breakfast 'snack' or two. The toaster needed a full-time attendant.
The site staff were keen on us prolonging our site presence or perhaps 'visit again next week to check everything is OK?'
'Sweat the asset' is usually when the owner/utility stops all maintenance and upkeep of a product, judging that they will get their bonus for 'saving costs' before the equipment conks out. It then becomes 'someone else's problem'.
This is why your roads are wrecked, rivers are polluted and services fail.
You are right but this problem was not cooling per se, as the panels would normally be cooled by ambient air and door-mounted fans. Atmospheric pollution attacking bare metal, (and warm metal at that), is more difficult to address. It is not usual to hermetically seal switchgear such as starters and control equipment on power drives. Modern practice on these sites is to contain or hugely dilute the source of the corrosion. At the design stage.
In sealing the building against ambient air changes, the issue of dissipating heat becomes a building problem. The consultants chose to install AC running in ducts under the ceiling.
We had some variable-speed drives housed in a switchroom which had air conditioning to keep the inverters cool. The inverter rating was about 500 kW so there was a few kW of heat to dissipate. Well the AC was good at cooling the filtered air extracted from outside......but...... The problem was that the site was a sewage works and a bit pongy...... The characteristic 'bad-egg gas', hydrogen sulphide, is very corrosive to copper. These inverters and cabinets had been carefully constructed with uncoated, high-copper-content wire and strips of copper to keep local losses to a minimum but inadvertently creating a huge surface area. Which promptly corroded..... and the corrosion product is conductive.... and flaky..... Inside, the cabinets had a thick layer of black copper sulphide (other spellings are available). All aided by polluted, external air being forced through the cabinets albeit cooled. After a couple of years, gosh it was a mess and the consequential short-circuits were spectacular.
Tinning the conductors could only be a partial cure (tin corrodes as well) so a new closed-circuit cooling system had to be installed with bigger coolers and standby in case of failure. We were fortunate that we had specified the requirements for the cooling air...... But when it was warm/hot weather this was the best building to be in as it was odour-free and blissfully cool.......>