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Member postings for Stuart Smith 5

Here is a list of all the postings Stuart Smith 5 has made in our forums. Click on a thread name to jump to the thread.

Thread: SKY abandoning their satellite customers
11/10/2021 19:28:53

Re excavations in public footpaths.

These are governed by the NRSWA (new roads and street works act). **LINK**

The specification for the excavation and reinstatement is detailed in this document: **LINK**

As public footpaths and roads are the responsibility of the local authority, they are responsible for issuing permits and checking that the utility company do the work to the correct standard. The utility companies pay fees to the LA and are issued with fines if they don’t comply.

Stuart

Thread: Home CnC
08/10/2021 14:01:13

Brian

There is a Denford micro mill in the ‘For Sale’ section on this site if that’s what you want. ( not mine, just noticed it!)

Stuart

Thread: Midlands Exhibition
22/08/2021 21:25:05

This was discussed in this thread

**LINK**

With the uncertainty about the changing Covid situation it was perhaps not wise to book non refundable tickets.

Thread: MEW article on coupling a stepper motor to a Vertex Rotary Table
05/08/2021 09:41:10

Are any of these suitable:

**LINK**

from CPC.

Stuart

Thread: GigaFactory
24/07/2021 00:50:31

Dave

The first part of your quoted Ofgem statement is correct. However, I think the second (highlighted) part is something they have invented recently!

If an individual or company want an increase in their supply capacity such as changing from single phase to three phase , it has to be paid for somehow. The customer who wants the increase could pay for the total cost, part of the cost, or none of the cost. Any cost they don’t pay for has to be paid for ultimately by the rest of us. Ie the DNO might pay but eventually would be reflected in everyone’s electric bills.

This from Ofgem is interesting:

**LINK**

and this :

**LINK**

looks like they have been thinking about this since 2018, but haven’t decided yet.

Regarding the existing capacity of the electric network , a figure of 1.5kW per house has been used for many years ( but has changed - not upwards in recent years) as the ‘after diversity maximum demand’ (admd) for a house with gas central heating.
So the required capacity for the network and substation is worked out using a simple formula of (a x n) + a constant to account for loss of diversity amongst a small number of properties (was 8 kW but this may have changed). Where n = no of houses and a = admd.

It won’t take many 7.4kW chargers on all night to overload a network.

Stuart

 

Edited By Stuart Smith 5 on 24/07/2021 00:50:51

Edited By Stuart Smith 5 on 24/07/2021 00:52:18

Thread: Silver Solder Stocks
22/07/2021 21:08:52

This document from the HSE outlines the health risks etc:

**LINK**

I wouldn’t have thought that changing rules on cadmium solder would be top of the U.K. governments priority, particularly in view of this document.

Thread: Digital CNC phase converter build
22/07/2021 10:45:48

John

I wasn’t suggesting leaving the star point floating, but to earth it via a separate earth electrode.

This would be the same as how the star point / neutral is earthed at an HV/LV transformer at a distribution substation.

Probably best to leave it to whoever installs this to decide the way to do it. I am not sure if there are guides in the wiring regulations to cover this situation.

Stuart

21/07/2021 18:28:30

I agree with John.

Did a bit more thinking about it and I think if the phase to phase voltage of the existing split phase supply is 480v, the generated voltage is 416 with respect to the existing neutral.

The only thing I would say is that if Robert goes down this route, the star point of his proposed delta/star transformer (ie the neutral for his 3 phase output) should be earthed separately and not connected to the existing supply neutral.

Stuart

Thread: The beginnings of Mobile Telephony
21/07/2021 14:08:50

This website has some interesting info on the history of mobile phones:

**LINK**

from Salford University

Stuart

Edited By Stuart Smith 5 on 21/07/2021 14:09:30

Thread: Digital CNC phase converter build
21/07/2021 09:00:43

Robert

Looks like you have it all covered.

Be interesting to see how the overall costs compare to having supply upgraded to 3 phase.

Stuart

20/07/2021 22:54:26

Robert

Yes, I was thinking of the voltages and phases measured to the existing neutral. I can see that for a delta connected supply, it would work as you say, so your idea of a delta/ star connected transformer would give a neutral and correct the voltages.

Regarding the supply capacity, as well as the kVA rating there is also the effect of any sudden changes in load such as welders and motors. Your DNO may have already told you what maximum welding and motor starting currents you can have. There is an Energy Networks Association (ENA) document Engineering Recomendation P28 which DNOs use to calculate these figures ( though they may have their own policies based on this).

**LINK**

Stuart

Edited By Stuart Smith 5 on 20/07/2021 22:57:59

Edited By Stuart Smith 5 on 20/07/2021 22:59:02

20/07/2021 22:10:13

Robert

As someone who worked for over 40 years as an electrical power engineer for my local DNO ( or electricity board as it used to be), I would suggest you check with SSE to see what load and motor starting currents you can take from your existing supply. As per my post in your previous thread on buying a lathe:

”Robert

Although the fuse carriers on your main DNO fuses may be labelled as 100A , you would be advised to check what current you can actually take from the network. I used to work at Electricity North West and the maximum supply capacity there was specified as 20kVA for a single phase supply ( ie 80A). The other issue may be that the rating of the pole mounted transformer may be a limiting factor. Also there are limits on voltage fluctuations caused by motor starting currents or welders (see ENA ER P28).

Stuart”

Regarding the ‘Phase Perfect’ - it seems to be anything but perfect.

It is clear from the diagram in this document

https://www.phasetechnologies.com/downloads/New_Phase_Perfect_Specifications.pdf 

that the two existing phases are used as they are and the third phase is generated electronically. So the two phases will be 180 degrees apart and presumably the extra phase will be 90 degrees from them. The phase to phase voltages will be as per the supply (ie somewhere in the 450 to 500 volt range depending on the loads on the network etc)

Stuart

 

Edited By Stuart Smith 5 on 20/07/2021 22:20:09

Edited By Stuart Smith 5 on 20/07/2021 22:20:59

Thread: 12 volt motor speed controller
19/07/2021 13:35:30

If it’s the type as Dave has shown, you could possibly unsolder the potentiometer from the board and fit it remotely. Get another pot of the same value and connect the 2 ends in parallel with the original pot and wire a changeover switch between the wipers of the 2 pots and the circuit board. One pot used to set normal speed and other pot to set fast speed. The switch used to select between normal and fast.

You will still need a change over switch on the output for forward/reverse.

The controller might not like changing from forward to reverse though without stopping the motor first as Dave says.

I bought a similar controller but one controlled by a signal from an Arduino. I managed to destroy it while experimenting with a small geared dc motor, so yours may suffer the same fate! I think the current rating is a bit optimistic.

 

I have since bought a different controller for use on a battery loco to control 2 x 12v 150w motors. I have tried it on the bench and on load. So far it’s seems ok.

A controller like this might be better for your application. It has remote pot and a reversing switch already fitted.

60A PWM Brushed DC Motor Speed Controller CW CCW Reversible Switches 12V/24V/48V.

11330e1c-26c3-4fbe-a31b-92cdaf1f0b49.jpeg

These are available from many sellers.

Stuart

Edited By Stuart Smith 5 on 19/07/2021 13:42:24

Thread: 4 Jaw Chuck Advice Please.
18/07/2021 15:16:27

This thread might help

**LINK**

and this post from Ketan particularly in the thread on 28/3

Stuart

Thread: Samsung mobile phone reset
18/07/2021 11:55:59

I did this probably 4years ago now, so unfortunately can’t remember the exact steps. I know I transferred everything (contacts/apps etc) from the old phone to the new one using the info from Samsung . **LINK**

This info from Samsung tells you how to do a factory reset: **LINK**

It doesn’t mention sending an email as far as I can see.

I don’t know if this is any help!

Stuart

Thread: Lathe diagram - loose wire from fuse
07/07/2021 22:04:14

duplicate post

Edited By Stuart Smith 5 on 07/07/2021 22:05:18

07/07/2021 22:04:13

I have a cj18a lathe and have a few photos of the control box and wiring but not in enough detail to show what you are looking for.

The end of the green wire looks a bit strange - it doesn’t look like it has been in a terminal. Does it look like the end has broken away from a soldered tag?

If so, it could have broken away from the switch terminal on the end of the pot. The one with the white wire to the indicator light.

You really need to trace the wiring from the mains incoming cable through the various components.

Note that on some of these lathes, the switches and fuses are in the neutral and not the live as they should be.

Stuart

Edited By Stuart Smith 5 on 07/07/2021 22:05:50

Thread: Model Engineer's Auction
02/07/2021 10:10:42

I emailed them back and suggested that they change the information page for this auction because it says VAT is payable on the hammer price.

I have just had a reply to say they have changed it.

Stuart

02/07/2021 09:19:48

I emailed the auction house last night to ask them about VAT.

I have had an email from them this morning confirming that VAT is only on the buyers premium.

Stuart

Edited By Stuart Smith 5 on 02/07/2021 09:20:04

01/07/2021 22:28:37

Duncan

In the terms and conditions it says buyers are responsible for collection but they do list 2 courier companies. Presumably you would have to arrange them to pick up, pack and deliver.

I have bought at a local auction which is online because of covid , and I picked up, but they had similar conditions.

Stuart

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