Industrial grade connector with safety switch

[sysrq]

Seems like can't find any industrial grade panel connectors with built in safety switch (when removing plug safety switch gets actuated and switches on or of contactors, relays or anything else). I need some protection against accidental or intentional removal of a plug. Interlocked commando sockets can't be used cause then it will be possible to plug it in any other socket.
I could make an enclosure with the socked inside and a safety door switch, only thing is then I will need another enclosure for it besides the one for control panel.
I could use multi-pole ILME connector with jumpers across some terminals, only thing is they need to be disconnected at least one second before the other terminals.

 

[Spoon]

I did something similar for a contract. I used a 10 way connector and put 2 links in it so that we detected when the plug was removed.

 

[Darkwood]

Lets get this right ....

You need to know when a plug has been removed....
You need to know 1 second in advance of it removal....

The only way I can see is a 2 stage process to remove it, as we are lacking so much info here its hard to give plausable answers, you could have a key lock system where to access the plug in an enclosure you have to switch a key in the main panel to either release the door or to access another key to open the enclosure... the switching of the panel key will act as your signal and gives you plenty of time before they can pull the plug once the enclosure has been released.

The issue here is we have no info on what exactly any of this set-up is for and a risk assessment may be required and a system to suit may have to be part of the safety system with timed release lock or it may just need a simple solution but without us knowing we cannot really guide you much more.

 

[sysrq]

Lets get this right ....

You need to know when a plug has been removed....
You need to know 1 second in advance of it removal....

The only way I can see is a 2 stage process to remove it, as we are lacking so much info here its hard to give plausable answers, you could have a key lock system where to access the plug in an enclosure you have to switch a key in the main panel to either release the door or to access another key to open the enclosure... the switching of the panel key will act as your signal and gives you plenty of time before they can pull the plug once the enclosure has been released.

The issue here is we have no info on what exactly any of this set-up is for and a risk assessment may be required and a system to suit may have to be part of the safety system with timed release lock or it may just need a simple solution but without us knowing we cannot really guide you much more.

It's a horizontal drum mixer, actually two of them. There will be a VFD for smooth start-up otherwise the barrel could fall off as well as speed adjustment to adapt to viscosity of the fluid with regular automatic reversing.
As I understand they want to unplug them after mixing and afterwards move it where needed (whole thing is on wheels). They will use them alternately so one VFD is enough.


And I think it would be better if the male socket would be on the drum mixer itself to avoid damaging the lead while moving it somewhere (the lead should be permanently attached to the control panel then). It would be better to use some circular shielded plug with three symmetrically arranged pins. Old type three phase plug could suit to some degree. I could order some similar plug as well but then it would be an over-engineering for such a small project, so I will have to use some rectangular ILME connector.

 

[Spoon]

Yes you have to have the male socket on the mixer. If it was on the end supplying power you would have pins that are live and able to be touched.
I think you may be over engineering this. Why do you "need some protection against accidental or intentional removal of a plug."? Is there something you are not telling us? If you unplug it the mixer will stop. Does the place where the mixer is being used employ muppets that have a craving to unplug anything that is plugged in?
What current rating does the socket need to be? Can't you just find something like a 5 way socket. Then they can't plug it in anywhere else.

 

[Darkwood]

Without going into the design nature of your intentions, why not use Harting connectors?

 

[Deleted member 78588]

Check out Marechelle.

They have a wide range of interlocked plugs and sockets.

MARECHAL® ELECTRICAL PLUGS & SOCKET-OUTLETS - Marechal Electric

They're not the cheapest but they're good quality.

 

[Deleted member 78588]

Sorry bout the double post.

 

[sysrq]

Yes you have to have the male socket on the mixer. If it was on the end supplying power you would have pins that are live and able to be touched.
I think you may be over engineering this. Why do you "need some protection against accidental or intentional removal of a plug."? Is there something you are not telling us? If you unplug it the mixer will stop. Does the place where the mixer is being used employ muppets that have a craving to unplug anything that is plugged in?
What current rating does the socket need to be? Can't you just find something like a 5 way socket. Then they can't plug it in anywhere else.

Well it's considered bad for the VFD to disconnect the load while there is a PWM signal on the output.
If I don't protect against it then I can rely on the fact that they will not unplug it while the drum is turning. They will see it when it's running anyway so I hope they will unplug it only when they have switched it off.

Harting or Ilme connectors should have sufficient current carrying capacity cause it's only a 0.5kW motor.

 

[Marvo]

Well it's considered bad for the VFD to disconnect the load while there is a PWM signal on the output.
If I don't protect against it then I can rely on the fact that they will not unplug it while the drum is turning........

Label the socket accordingly that the VFD must be isolated before unplugging. You can't design to accommodate stupidity, stupidity will always win.

 

[Spoon]

You can't design to accommodate stupidity, stupidity will always win.

haha sooo true.

 

[sysrq]

The issue here is we have no info on what exactly any of this set-up is for and a risk assessment may be required and a system to suit may have to be part of the safety system with timed release lock or it may just need a simple solution but without us knowing we cannot really guide you much more.

Yeah normally these things are behind a industrial safety fence. The drum mixer can be turned on only when the fence is closed. It prevents from possibility of barrel falling on to the feet, another option is to wrap around some loose chains/ropes so it can't detach itself from the rollers.

 

[Darkwood]

Yeah normally these things are behind a industrial safety fence. The drum mixer can be turned on only when the fence is closed. It prevents from possibility of barrel falling on to the feet, another option is to wrap around some loose chains/ropes so it can't detach itself from the rollers.

So you now express there is usually a safety fence due to risk assessed hazards but there is no longer one, well I would personally walk away from this or ensure the original required safety precations are reinstated, to not do so you alone take on the responsisbilty of any injuries or deaths resulting from lack of safety measures been implemented as you are the one doing the electrical control works, If you cannot see this as a issue then you should not be involved with any new, additions or extensions to any such control systems.

 

[sysrq]

So you now express there is usually a safety fence due to risk assessed hazards but there is no longer one, well I would personally walk away from this or ensure the original required safety precations are reinstated, to not do so you alone take on the responsisbilty of any injuries or deaths resulting from lack of safety measures been implemented as you are the one doing the electrical control works, If you cannot see this as a issue then you should not be involved with any new, additions or extensions to any such control systems.

There wasn't any safety fence before as it's a completely new machine made from scratch. According to international requirements there should be a safety fence with a safety interlock switch.

 

[Darkwood]

There wasn't any safety fence before as it's a completely new machine made from scratch. According to international requirements there should be a safety fence.

Your own documented risk assessment should also hi-light the requirement for one backed up by the relevent safety standards, without it meeting these standards the machine cannot be sold as a working model and only as a project for upgrade - something very dodgy is going on here if you have been sold this machine as a complete unit yet it basic safety features missing.

 

[sysrq]

Your own documented risk assessment should also hi-light the requirement for one backed up by the relevent safety standards, without it meeting these standards the machine cannot be sold as a working model and only as a project for upgrade - something very dodgy is going on here if you have been sold this machine as a complete unit yet it basic safety features missing.

Let this case serve as a severe warning for anyone else. Sooner or later accident will happen.

This is not a commercial project.

 

[Darkwood]

Let this case serve as a severe warning for anyone else. Sooner or later accident will happen.

This is not a commercial project.

I'm sorry, I'm getting a tad confused here, your recent history shows a lot of similar questions so exactly where are these questions coming from, when asked you seem to supply relevent info as though these are active projects, if anyone is to use these machines and control systems then they have to meet all relevent regulation for safety standards and machine control guidelines regardless of where this machine is installed - your concerns on this thread are others pulling the motor plug while it is running - this suggests it is not a private garage project for your own use only.

 

[sysrq]

Label the socket [:smartass: ] accordingly that the VFD must be isolated before unplugging. You can't design to accommodate stupidity, stupidity will always win.

Is there anything in BS 7671 about safely disconnecting the motor from the VFD if there is connector in the load side? I don't know if Toshiba vf-s11 is protected against it cause in the manual there isn't anything about it. Nowadays we have a fly-back diode across each transistor in the VFD as a protection against stupidity.
I guess if nobody makes EMC connectors (good 360 degree connection) with simple early break contacts for the VFD then it's not allowed to use them (few available only for high power VFD's). There are many who don't care about correct impedance mach or EMC compliance (VFD acts as a high power radio transmitter in wide spectral coverage) and put all sorts of switches in-between the motor and VFD.

It seems strange that there aren't any Harting type connectors with early brake pins or auxiliary switches either. We have only isolators with with an early break auxiliary conntacts.

 

[Darkwood]

Is there anything in BS 7671 about safely disconnecting the motor from the VFD if there is connector in the load side? I don't know if Toshiba vf-s11 is protected against it cause in the manual there isn't anything about it. Nowadays we have a fly-back diode across each transistor in the VFD as a protection against stupidity.
I guess if nobody makes EMC connectors (good 360 degree connection) with simple early break contacts for the VFD then it's not allowed to use them (few available only for high power VFD's). There are many who don't care about correct impedance mach or EMC compliance (VFD acts as a high power radio transmitter in wide spectral coverage) and put all sorts of switches in-between the motor and VFD.

It seems strange that there aren't any Harting type connectors with early brake pins or auxiliary switches either. We have only isolators with with an early break auxiliary conntacts.

Why are you asking about the BS7671 - this is outside the scope of the BS7671, if you had the appropriate guidelines/standards which are based on the European L.V.D. then you would be aware of this, can you clarify exactly what standards you are following when doing this work?...

 

[Barry White]

Use a harting conector and see post 2
Are you building this machine? or modifying it if so be careful as you the designer/installer will be liable