Workshop Safety

[chuckkey]

I've got a small metalworking lathe which runs off a normal 240v single-phase supply (its only 550w). Even although its fixed to a bench, it's plugged into a normal single socket in the spare room which acts as my workshop.

I'm sorting out the workshop and am planning to change it to one of those MK neon-switched fused outlets, rather than the plug (to stop my wife unplugging it )

i.e. http://www.screwfix.com/p/mk-13a-dp-switched-fused-connection-unit-with-neon-white/58085

For safety I would like to also install an NVR (no volts release) switch inline (so that after a power cut the lathe doesnt automatically restart when the power is restored). i.e. http://www.axminster.co.uk/axminster-nvr-switch

This is the bit i'm not sure about I can just mount that on the wall, run some flex from the outlet to that then from there to the lathe right? Its the wiring of it that scares me - specifically the earthing arrangements (the machine is earthed from a choc block near the motor, through the plug atm) Is it simple or best to get a spark to do it (rough prices?)

Also, any RCD protection required (The main CU for the house has none, old fusebox with wire, not MCBs)?

 

[plugwash]

I would give some thought to how you will isolate the lathe for maintinance/adjustments and when not in use. IMO FCU switches are too sensitive to accidental operation to rely on them for this purpose. The buttons on the no-volt release you have linked look better (the on button but I would still think carefully about where you site it to minimise the risk. Unplugging is pretty much the ultimate isolation, why do you consider your wife unpluggin the lathe to be a "problem"?

You can also get NVR switches with hinged covers e.g. http://www.axminster.co.uk/axminster-kjd12-switch (that one would need mounting on a suitable enclosure if you wanted to use it standalone) which require a very deliberate action to turn on and can be locked off.

I would also think carefully about where you run your wiring. You don't want to run ordinary flex where it is vulnerable to damage.

As for earthing the general rule is that earths should follow the corresponding live conductors. I would expect your no-volt release would have an earth terminal where you can join the earths but if it doesn't then just use a bit of terminal block.

As for RCD protection I'm pretty sure it's not a requirement but that doesn't mean it's not a good idea. If your socket circuit doesn't already have RCD protection i'd be loking in to adding it.

 

[Taylortwocities]

Warning on the safety front.
What type of lights do you have in the room? Certain types of fluorescent lights have a flicker that the eye does not detect. It does have a stoboscopic effect on moving items (your lathe) which may appear to be stationery when in fact it is running.

If you have florries, change them for an HF type that does not have this "feature"

 

[winston1]

I'm sorting out the workshop and am planning to change it to one of those MK neon-switched fused outlets, rather than the plug (to stop my wife unplugging it )

i.e. http://www.screwfix.com/p/mk-13a-dp-switched-fused-connection-unit-with-neon-white/58085

For safety I would like to also install an NVR (no volts release) switch inline (so that after a power cut the lathe doesnt automatically restart when the power is restored). i.e. http://www.axminster.co.uk/axminster-nvr-switch

This is the bit i'm not sure about I can just mount that on the wall, run some flex from the outlet to that then from there to the lathe right? Its the wiring of it that scares me - specifically the earthing arrangements (the machine is earthed from a choc block near the motor, through the plug atm) Is it simple or best to get a spark to do it (rough prices?)

Also, any RCD protection required (The main CU for the house has none, old fusebox with wire, not MCBs)?

I've got a small metalworking lathe which runs off a normal 240v single-phase supply (its only 550w). Even although its fixed to a bench, it's plugged into a normal single socket in the spare room which acts as my workshop.

I'm sorting out the workshop and am planning to change it to one of those MK neon-switched fused outlets, rather than the plug (to stop my wife unplugging it )

Have you not considered an A4 sheet of paper with "DO NOT UNPLUG" written on it in big letters stuck to the wall above the plug?

 

[chuckkey]

@plugwash/@winston1 - I see where you are coming from about a switched outlet being knocked by accident . The reason I don't like the wife unplugging things in the workshop, is because I don't want her to come in and end up hurting herself leaning over and cutting herself on things like the 4 way tool post when looking for somewhere to plug in the hoover etc. A fixed installation would prevent that, hopefully. But good point.

On the second point, agreed - I would also rather not have long lengths dangling flex anywhere near the chuck for obvious reasons, I was planning to keep it short (coming up from floor level) and mounting the button on the side of the bench at the headstock end (the wire from the plug currently goes in the back of the headstock)

Right now there is no RCD protection on the socket circuit as the fusebox is prehistoric. The house is in need of a rewire tbh (old CU, old colour wiring, unearthed lighting circuit etc...)

@Taylortwocities - i've got an incandescent bulb in the room, and halogen work lamps on the benches which seem to work ok (heve heard before of fluorescents strobe effect making a spinning chuck look stationary)

 

[ban-all-sheds]

The reason I don't like the wife unplugging things in the workshop, is because I don't want her to come in and end up hurting herself leaning over and cutting herself on things like the 4 way tool post when looking for somewhere to plug in the hoover etc. A fixed installation would prevent that, hopefully.

So would installing a socket for her to use for the hoover, which you'll have to do anyway if you swap the one she uses now for an FCU.

 

[stillp]

You can also get NVR switches with hinged covers e.g. http://www.axminster.co.uk/axminster-kjd12-switch (that one would need mounting on a suitable enclosure if you wanted to use it standalone) which require a very deliberate action to turn on and can be locked off.

That isn't lockable. I think they mean that it latches, but latching on those devices is very hit and miss, just one of the reasons why they don't meet the standards for emergency stop devices. The one the OP linked to is much better http://www.axminster.co.uk/axminster-nvr-switch

 

[JohnW2]

That isn't lockable. I think they mean that it latches, but latching on those devices is very hit and miss, just one of the reasons why they don't meet the standards for emergency stop devices. ...

The yellow hinged cover looks as if it's designed to be padlocked - is there an 'on' button beneath it? (if so, it could presumably be 'locked off'??).

Kind Regards, John

 

[stillp]

That isn't lockable. I think they mean that it latches, but latching on those devices is very hit and miss, just one of the reasons why they don't meet the standards for emergency stop devices. ...

The yellow hinged cover looks as if it's designed to be padlocked - is there an 'on' button beneath it? (if so, it could presumably be 'locked off'??).

Kind Regards, John

Where do you see anywhere to put a padlock John? That silly red/yellow cover has beneath it something very much like the OP's link http://www.axminster.co.uk/axminster-nvr-switch
I suppose it might be possible to get a thin padlock into that yellow loop that the red part is supposed to latch into, but it will fail the robustness test for disconnectors. HSE don't like padlockable emergency stops by the way, their view is that it encourages people to rely on the e-stop to prevent unexpected start-up, whereas they should be using a padlocked switch-disconnector.

 

[JohnW2]

Where do you see anywhere to put a padlock John? ... I suppose it might be possible to get a thin padlock into that yellow loop that the red part is supposed to latch into ....

There appears to be one 'yellow loop' going through another 'yellow loop'. I assumed that was for a padlock. If not, what is the purpose?

Kind Regards, John

 

[stillp]

As I said above, it is supposed to be the latching mechanism.
Its purpose is to fool people who know no better that it is suitable for use as an emergency stop device.

 

[JohnW2]

As I said above, it is supposed to be the latching mechanism. Its purpose is to fool people who know no better that it is suitable for use as an emergency stop device.

I see!

Kind Regards, John

 

[chuckkey]

Anyway, I've ordered the NVR switch. I've decided not to fit a fused switched outlet for the time being. Ps the machine already has a prominent emergency stop button so that won't be required, but thanks for the replies anyway (it's an older model of the Warco WM240B).

 

[ericmark]

Using a RCD FCU active type will stop restart after a power cut so would seem best option.

 

[ericmark]

Warning on the safety front.
What type of lights do you have in the room? Certain types of fluorescent lights have a flicker that the eye does not detect. It does have a stoboscopic effect on moving items (your lathe) which may appear to be stationery when in fact it is running.

If you have florries, change them for an HF type that does not have this "feature"

You have a valid point. Never thought about LED lamps will they cause the stroboscopic effect? I would guess where a switch mode regulator is used no. But how does one know what the unit contains?