Member postings for Chris Pearson 1

I trust that Milly has an answer, but by way of thread drift, my modern car has no dipstick so the only way out is via the drain plug. Somewhere in there must be a level gauge.

RS are seldom the cheapest.

I tend to prefer Facom, but they are not cheap either.

In my experience, drivers are very happy to place a pallet in any reasonably convenient spot. The exception was recently when I had a pallet-load of bricks delivered. He didn't have a pallet truck so he just lifted them over the boundary wall with his HIAB.

I'd use my engine hoist - you may be able to hire one locally.

A piece of metal (any metal) which is sufficient for making one article.

Top tip: don't get in a fight with Ian Parkin - he must be very strong.

You are not the only one! I had a dreadful night last night. It started with being cold, and ended with incredible thirst and drenching the sheets. Better now!

What do you want to make?

I think that the driver should be (round) things that you want to make. Then you need to figure out how to do it and just get on with it. Try to make your mistakes early in the process. We all make them and have to start again, but it is easier to do so near the beginning.

I agree with the first point, but as I said above, some bolts are screws and some screws are bolts.

My understanding is that if, for example, two plates are bolted together, the tension in the bolts clamps the plates such that the friction between them exceeds any shearing force. The shanks of the bolts themselves should not be subjected to a shearing force.

Yesterday, I measured 3.0 A. It seems to fluctuate quite a bit. Generally, it seems to lie between 10% and 25% of the current in the Line.

There are many sorts of bolts, such as a projectile fired from a crossbow, part of a firearm, a door catch; but this is what OED says about our sort:

"A stout metal pin with a head, used for holding things fast together. It may be permanently fixed, secured by riveting or by a nut, as the bolts of a ship; or movable, passing through a hole, as the bolts of a shutter."

A screw has a helical thread, but they are not necessarily for holding things together. You probably have one on the front of your lathe.

Robert, A couple of hundred Ohms of resistance in an TT earth path might make a milliamp or two of difference, but that is not my point.

If the supply is TN-C-S and there are any diverted neutral currents, they will swamp any earth leakage so you cannot necessarily measure it by looking at the current in the earthing conductor.

I was referring to the N-E link, which is normally in the service head, but there will almost certainly be other links nearby such as a neighbouring property or street lamps.

Some of my electrons appear to be going from N to E then through the bonding to the gas pipe then to at least one neighbour's gas pipe, along their bonding to the main earthing terminal and then back to the transformer via E or N, or a combination of the two.

Just now, I got a reading of 0.40 A with my clamp meter around L, N, and E together.

Then I think that you can quite reasonably conclude that your machines are sound.

However, with TN-C-S current in the earthing conductor may have nothing to do with leakage so if you find it, you cannot conclude that something is amiss.

(And don't forget that even with what looks like TN-S, there may be N-E links nearby.)

Yes, I think so, but that is exactly what you want to avoid - you do not want the bed of your machine at anything above earth voltage. There is a big difference between faulty insulation and earth leakage. If the bits and bobs in your VFD are "leaking" they are supposed to return to earth via the CPC.

If there were no earth leakage at all, why have RCDs at 30 mA rather than say 10 mA. (Yes 10 MA ones are available.)

Yes, but a really good earth rod in damp soil might manage 20 Ohms and the same at the transformer. By contrast, the earth path through all the green and yellow might be, say 0.5 Ohm. So assuming that any earth leakage is to the bed or case of the machine, the vast majority (99%+) will go down the green and yellow.

The insulation of your junction box should be sound. Around one megaohm is about the minimum acceptable resistance, but a new machine in good order should achieve one gigaohm.

I am afraid that it is not quite as simple as that.

What type of earthing do you have please: TN-S, TN-C-S, or TT?

(FWIW, the current in my earthing conductor when I started writing this was 0.17 A, but Mrs P. has just put on the tumble drier and it has gone up to 3.5 A.)

Hang on - this is all getting a bit muddled.

If you think that there is high earth leakage, you need to measure or calculate it, which requires access to the conductors individually. I see no advantage in testing L & N together as opposed to the CPC. If the device is bonded and you test L & N together, you do not know which route any missing electrons are taking.

Only: (1) if there are any extraneous CPs (which is seldom the case in modern homes); and (2) the device is attached to an ECP and the fault or leakage is to that.

No, that is not correct.

The lens and iris are controlled by smooth muscles, which cannot be exercised like striated muscles.

Presbyopia arises from stiffening of the lens, not weakening of the muscles.

The extra-ocular muscles swivel the eyes.

The great thing about natural eye lenses is that they can alter their focal length.

The problem is that the cornea might not focus correctly.

Right now in the interval of the Wales/Australia match, I am reminded that by my mid-teens I could not see the ball at the far end of the pitch. You could wear spectacles for cricket (I have seen a young Sir Geoffrey do so) but not rugby and we did not have contact lenses in those days.

Don't forget that one can wear one's short-sighted -ve lenses with +ve reading glasses at the same time.

For some reason, people think that it is a little odd.

You can put your clamp meter around line and neutral together, or CPC, but it doesn't make any difference.

You could even put two AVOs in the line and neutral and calculate the difference.