Cable Gland

Hi Clive

you mention the motor is rated at 1.5HP Full Load current of 6.9 A. A 1.5 mm flexible cable would be fine.

have a look at **LINK** for cable ratings.

i would prefer motor supply separated from the control/E-Stop circuit.

John

As the current carrying capacity of 1.5mm wire is nearly 20A, it will do.

I'd say going to the trouble of sourcing a short length of 5 core cable is more trouble than it's worth. Appropriate for long runs where there's a need to clearly identify the cores, but Over The Top in this application. (Of course no harm in using multicore cable if you already have some.)

I'd just use a length of mains twin core and a length of mains three core held together with string or a length of spiral cable tidy (this example sold by Amazon). A manufactured item would likely use a wiring loom, ie 5 single core wires held neatly together with thin cord and routed to avoid hazards. Looms are usually made to size on a frame and fitted with terminators ready for assembly, but no reason not to make similar on the spot.

The most objectionable part of the circuit is the long wandering live cable connecting the safety interlock switches together. If it falls off, there will be a dangling shock hazard. You could reduce the risk by fixing the cable down firmly with clips, or even better by running inside a conduit. (Plastic conduit is used to protect mains cabling in homes.) A better answer is to operate the interlocks with low voltage. The interlocks would operate a contactor next to the control box, and the contactor would manage the mains. But as that involves more expense and complexity, I'd go with what you've proposed.

Health and Safety is about managing risk. You've spotted some risks with the original machine and are taking steps to reduce them, which is good! The proposed fix introduces some new electrical risks which need the same consideration. Basically earthing all external metal parts, and making sure adults, children, and animals can't touch a live wire, including the possibility that a live wire might vibrate loose, snag, or chafe. I think the last 3 risks are why the long run between interlock switches needs attention : I'd probably protect it with conduit or any other practical way of securing the wire safely. The end goal is to make the machine safer than before, not to meet the highest possible standards. (The way houses are wired would be unacceptable on a ship, because ship electricity involves mores risks. Wiring a home to nautical electrical standards is a waste of time and money because - for example - it's unlikely a home will ever be soaked in salt water, or have it's wiring storm tossed or shaken continuously by a massive Diesel. ) If the risks presented by this old machine are mitigated, that's good. No need to fit a fancy waistcoat.

Dave

Edited By SillyOldDuffer on 24/02/2020 10:05:02

Johnboy

“i would prefer motor supply separated from the control/E-Stop circuit”.

Can I ask you, why the preference?

Emgee / Johnboy

I’m going to apologise before I even ask this next question, can you take a look at the revised wiring sketch.

Am I right in assuming when you say “Remove the brown live to the motor from T1 (2) and terminate in T2 (4)
Wire a 1.5mm size link from T1 (2) to L2 (3)”

The new termination will be as I’ve indicated in Red for the motor live wire and the link wire should run as I’ve indicated in Blue and not where I’ve shown it in Green, the reason I’m asking is there are two terminals 2 T1??

Blue wire is showing correct connection, the other T terminals on the contactor have the 3 o/l legs connected.

Emgee

Sillyoldduffer

Thank you for your input, the cable to the interlock switches will be cable clipped to the underside of the table and are also set well back from the edge of the it behind the angle iron framework, so if I move the table about my hands will not be coming into contact with the wiring.

Clive

[This posting has been removed]

Emgee

Thanks for clarifying the cable connections for me.

I may as well find out, Looking at the DOL picture Iv'e already posted, am I right in assuming the little square test button is so the overload coil can be tested periodically much the same as an mcb in a consumer unit is tested.

I can also see a small blue reset switch, is that to reset it after the test button has been pressed or indeed to reset it should the overload coil be activated at any time?

Clive

Clive...

it’s consider good practice to keep control and power separate and i’m being a bit old school 😳 The middle terminals are only the connections between the contactor and over load relay - no wiring should be connected to these terminals.

can’t get the marked photo to load up...

Clive

Check the documentation that came with the starter for details of any test buttons.

Emgee

Bill

Yes, I know what you mean about mini trunking I’ve used it myself in the past, glued, nailed, screwed whatever it takes to get it to hold, I don’t think it will be glued not with all that shaking going on.

At the end of the day I suppose it comes down to whatever is desirable, I must admit I was going to settle for just clipping the wire and because such a big hole needs to be drilled to accommodate glands, I was going to just loop the cable under the angle iron.

But since you’ve mentioned mini trunking I’m now debating whether to use that and do as someone else suggested cut a grommet into two pieces and glue them into the hole both sides of the angle.

Clive

Photo Sorted. 👍

the cabling to the E-stop would better in two core flex. 3182Y if you haven’t got two core standard 3 core 3183Y and ignore the green/yellow earth.

john

Edited By Johnboy25 on 24/02/2020 22:16:33

Emgee

I don’t have any documentation; I suppose I could Google Moeller MSE-M240V and see if that turns something up.

Not to worry though as long as it works that’s fine by me.

Clive

The sq Red Test button is operated by the cover mounted stop switch, the top Test plate is operated by the cover start button, you can of course use them with the cover removed if the power is on, you will then be working live so take care,
The blue piece with cross slots is to set the overload to reset manually or automatically after an overload condition, suggest this is set to M so you have to press the stop button to reset the overload trip.

Emgee

Emgee

Would you be good enough to take a look at the photo Jonboy as modified and confirm it’s as the sketch below:

You will see I've removed the incorrect green wire.

I guess I just want to be sure we are all singing from the same hymn sheet.

Thanks for explaining about reset button, how stupid of me of course the buttons on the outer cover have got to press against something or I'd be pressing them forever.

Its late and was just going to turn my PC off when I saw the lasts posts on this thread. The thought then came to me that most of the topic has been about emergency stops.

I know these are so the motor can be stopped from any side of the machine but I then wondered how the machine can be started from any side of the machine?

If these are purely 'emergency' stop buttons then how is the motor started and stopped in normal use?

The original machine has an on/off switch on the motor its itself, it looks like a simple mechanical switch so presumably you intend to leave it permanently in the ON position and control the motor from your DOL mounted on the wall. Does this mean that you might have to walk round to the other side of the machine after you have started the motor?

Sometimes (and I'm guilty of this too) its possible to get carried away on a particular route to solving a problem without really analysing what the problem is. In this case the more switches, wiring, terminals, circuitry and other components that seem to be increasingly involved, the more likely that faults and operational complications will be possible.

The keep it simple approach has a lot in its favour, why not have a length of string strung just overhead that pulls out the 13A plug (like the communication cord in a train carriage). OK thats crude and its not really a serious suggestion but the proposed system of emergency stop switches carrying mains voltage does seem a good idea either.

What one does in their own home workshop does not have to be to industrial standards (its for your own use and its not operating 24 hours a day) but where possible it should at least be based on sound practice.

Rantover

Ian P

Clive...

that’s fine - your diagram concurs with what I was trying to describe.👍

John

Clive

You need to look at the electrical schematic shown on the earlier picture of the inside of the starter cover and compare the hand sketches with connections shown in the schematic. Follow the wiring format shown in the schematic.

There is no connection to A1 in the hand sketches, this is the live for the coil so the contactor will not function.

Emgee

Ian P

When I purchased the machine from new all it ever had was the no volt switch on top of the motor.

The cable came out from the side of the switch box and had a three pin plug on the end of it. Because I did not want to drape the cable over the top of the machines for obvious reasons, it was passed down through the same hole the chip extraction hose goes through and from there was plugged into a convenient socket outlet on the wall.

To turn the machine on or off was a case of having to reach over to do so, as matter of fact sometimes when I wanted to switch the machine off, I’d use a piece of wood save stretching over.

My plan now was to fit emergency stops and bring all the wiring from them into the switch box on top of the motor, doing away with the original switch altogether and putting a steel blanking plate on top of box.

The cabling would then come out of the side of the switch box including the power supply for the motor down through the hole in the table and the DOL would be fastened to a board and either hung on the side of the machine I’m working on or on the wall and from there a short cable with a three pin plug would be pushed into a convenient power point.

I’d love to be able to fix the DOL starter in one permanent position but because the whole machine has to be moved around due to space limitations, I can’t do that. ie if the machine was pushed against the wall the DOL was permanently fixed to I’d never be able to reach it.

Ian I dare say a lot of the guys on this forum have metal turning lathes or mills, a woodwork machine such as mine needs a lot of space, think about it, if I have a piece of wood to be planed and say its 8 foot long the machine will need at least 18 feet, 8 foot going in and 8 foot coming out plus enough space to feed it in and get it out of the machine so that’s why sometimes the machine is shoved up against a wall.

Believe me I am trying to persuade my wife we need to move, I am working on it .

As you can see I’ve never had E/stop buttons on the machine, I was thinking I could use them to turn the machine off without the need to turn off at the DOL, having said that I don’t even know if this would have any adverse effect on the DOL or indeed if an E/stop has been operated I’d have to take the cover off the DOL and reset anything I’m hoping not.

Thank you for your comments they are much appreciated .

Clive