What Is The Oldest

[Midwest]

No, none of it was energised at the time and we weren't in the building, a fire started in the roof and spread thoughout this wing of the building. Some had recently been rewired and the remainder was about to get done - Sintra was running the E+M side of the job so his project took a bit of a change of direction too.

I was only joking, but I can understand you making things clear.

 

[GLENNSPARK]

No, none of it was energised at the time and we weren't in the building, a fire started in the roof and spread thoughout this wing of the building. Some had recently been rewired and the remainder was about to get done - Sintra was running the E+M side of the job so his project took a bit of a change of direction too.

It's a great pity lucien when stuff like that is lost

 

[GMES]

That's a real shame Lucien, as Glenn said ! shame to lose that kind of thing.

 

[Sintra]

No, none of it was energised at the time and we weren't in the building, a fire started in the roof and spread thoughout this wing of the building. Some had recently been rewired and the remainder was about to get done - Sintra was running the E+M side of the job so his project took a bit of a change of direction too.

Still on that job. It'll be 2 years next month but we've managed to complete most of our works on the undamaged section of the building. It's been a grind but it's nearly done, hopefully in another 4 or 5 weeks we'll be complete. The only burning question pardon the pun is if we will get the works to redo the damaged grand hall.

 

[GMES]

Fingers crossed for you Steve.^^^^^

 

[westward10]

Worked in plenty of churches but the oldest wiring I have seen still in was in a factory in Bath about ten years ago. Throughout the basement store rooms pairs of VRI conductors were strung across the ceilings on ceramic cleats. Thought nothing of it until I tested the lighting circuits down there and realised they were still live!

 

[Deleted member 93172]

Petworth House complete rewire, Churches

 

[westward10]

Switch fuse with fused neutrals supplying lighting in a shop, as you can see it can be opened whilst energized because the switch doesn't function.

 

[Lucien Nunes]

A mere 60 years old but also nearly 100% original and still in full time use, I think I posted about part of this on one of my puzzle threads a few years back. It's a 7hp Ward-Leonard variable speed drive on a Swiss-made horizontal borer. The MG-set is a long thin unit comprising an induction motor, DC generator, exciter and cross-field amplifier machine all on one shaft running at 2900 rpm. The output to the spindle motor is something like 0-270V DC at 0-65A, controlled using voltage feedback via a magnetic amplifier driving the Metadyne, which in turn drives the main generator field. Allied with two mechanical gears, the spindle speed range is around 60-3000 rpm in either direction with full torque at all speeds

Inverter drives might be smaller, quieter and more energy efficient in the midrange but at low speeds these old DC drives massively outperform them as they maintain full torque all the way to zero. Without any mechanical brake, the spindle locks rigid when stopped because the servo generates an opposite torque to resist any attempt to alter the speed (from zero). With great effort I can just about get the chuck to budge a little at a time, and the same applies to any variation in target speed when running.

Plus there's a sense of ceremonial importance that you don't get with a VFD - you press the converter start button, that spins up, you hear it switch to delta, the DC contactors switch to standby and the big red light comes on meaning control system ready for you to start the spindle motor...

 

[Videodoctor]

I worked in a farm house in Lancashire that was built in 850 AD.That predates 1066's Battle Of Hastings!.

 

[Lucien Nunes]

Here's another organy one. This blower dates from 1936-7 and is still in use in its original installation. Slipring 18hp motor with 3-stage pneumatic rotor starter, drives dual-inlet main blower and 4-stage booster. Also drives 18.5V 100A generator to power the electric action, with separate 12V 30A exciter. The generator is interesting - it's rated for 100A continuous load but peak currents can be much higher e.g. when changing a lot of stops at once. The 18V circuits are heavy (19/.064) but some sections are long and drop can be 10-20%. So the generator is over-compounded, i.e. the series field has enough turns to increase the generated EMF by more than its internal drop as the load increases. The output terminal voltage rises one volt per 40A load, i.e. the dynamic resistance is -0.025Ω (yes that's negative resistance) which approximately cancels out the drop in the DC distribution cables and submains.

 

[GLENNSPARK]

Here's another organy one. This blower dates from 1936-7 and is still in use in its original installation. Slipring 18hp motor with 3-stage pneumatic rotor starter, drives dual-inlet main blower and 4-stage booster. Also drives 18.5V 100A generator to power the electric action, with separate 12V 30A exciter. The generator is interesting - it's rated for 100A continuous load but peak currents can be much higher e.g. when changing a lot of stops at once. The 18V circuits are heavy (19/.064) but some sections are long and drop can be 10-20%. So the generator is over-compounded, i.e. the series field has enough turns to increase the generated EMF by more than its internal drop as the load increases. The output terminal voltage rises one volt per 40A load, i.e. the dynamic resistance is -0.025Ω (yes that's negative resistance) which approximately cancels out the drop in the DC distribution cables and submains.
View attachment 33181
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tasty...

 

[westward10]

Here's another organy one. This blower dates from 1936-7 and is still in use in its original installation. Slipring 18hp motor with 3-stage pneumatic rotor starter, drives dual-inlet main blower and 4-stage booster. Also drives 18.5V 100A generator to power the electric action, with separate 12V 30A exciter. The generator is interesting - it's rated for 100A continuous load but peak currents can be much higher e.g. when changing a lot of stops at once. The 18V circuits are heavy (19/.064) but some sections are long and drop can be 10-20%. So the generator is over-compounded, i.e. the series field has enough turns to increase the generated EMF by more than its internal drop as the load increases. The output terminal voltage rises one volt per 40A load, i.e. the dynamic resistance is -0.025Ω (yes that's negative resistance) which approximately cancels out the drop in the DC distribution cables and submains.
View attachment 33181
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Excellent

 

[Lucien Nunes]

It's interesting to think that at 80 years old, it has probably outlived all the men who designed, made and installed it, and provided no-one b***ers about with it there's every chance it will outlast not just us but the generation we hand it over to. Just needs a sip of oil and a turn of grease every 6 months (all the bearings are sleeve oil-ring types except one inside that is grease-lubricated as it's in the airflow) and the usual maintenance to brushgear. The generator tends to suffer from oil seepage onto the comm - we have to solvent-clean the brush holders, brushes and comm once a year or they stick and risk the output going intermittent which could be a showstopper. It could do with the armature out, comm skimmed, and a bigger flinger ring made for the comm end shaft. Maybe next decade.

 

[GLENNSPARK]

Place I worked at once had a redundant very old hoist for lifting bales of wool

Went up in the rafters to have a look at it just to be nosy...like you does

Rotor were suspended on babitts..lol

 

[Lucien Nunes]

Now there's an art - pouring and handscraping a bearing. How many mechanics even know what that is now?

 

[GLENNSPARK]

Now there's an art - pouring and handscraping a bearing. How many mechanics even know what that is now?

You could use the shaft....to create the form for the babbit...

What you did...was cover the shaft with 'lamp black'....this stops the babbit from sticking

Once poured you then cleaned it all up then reassembled...spin it by hand...then disassemble... your looking for 'witness marks'...their the high spots.....which you shave down by hand...until true

A bit of marking blue tells if everything is OK and good to go....

 

[Barry White]

Still got my scraper and engineers blue but carnt remember ever scraping a white metal bearing. Mainly brass bronze or cast iron.

 

[GLENNSPARK]

Still got my scraper and engineers blue but carnt remember ever scraping a white metal bearing. Mainly brass bronze or cast iron.

Oillite bronze is still commonly used for wear faces....

Still a lot of gunmetal bearings about....

 

[The Ghost]

Around 40 years ago, just starting really in electrics, I worked on Craigdarroch house near Moniaive in Scotland. I believe that dates back to the 14th C.