3 Circuits Into A Drive Cabinet.

[Spoon]

Hi people,

Can you please help me out.
I guy on site has sent back some marked up sketches of changes done on site.
On is a change to some 3rd party grease systems we added. 2 off. Each system has its own dedicated breaker and circuit.
What he has done, to stop them running all the time, is to add a relay in the press drive cabinet. This energises when the press is running. He has then fed the 230v supply from each grease system breaker through a NO contact of this relay in the drive cabinet, thus the grease systems only get powered when the press is running.
I know that this is against regs. E.G. EN 60204: 5.1 & 5.3.1. I thought there was more but just can’t find them. Any help would be appreciated.

 

[Bobster]

Those pretty much cover it.

Is it possible to pass the feeds through rated aux contacts on the press cabinet disconnector?

 

[Spoon]

You would have thought that would have been a good way to go Rob.
Not shown that way on the marked up sketch.

 

[Bobster]

It'll need to go through the disconnect.

Can the 240V feed not come from the main drive panel itself? Just fit the MCB's inside.

Also is a relay man enough to deal with the current needed to run the grease units? I'm presuming they are auto greasers? just consisting of a timer and a solenoid?

 

[Bobster]

However, so long as a suitable legend in accordance with 16.1, and he's used appropriate orange wiring that is separated from other circuits in the main panel.

There is no need to change it, only a recommendation from 60204.

 

[Darkwood]

As you have expressed, this set-up doesn't comply with both the BS7671 nor the BS60204, why can't you run the grease units of the press supply itself and just intergrate it into the control system, at present you have 3 seperate supplies running through one control system and also it means an inherent risk to any maintenance who isolate the press power upstream could be at risk they are not aware that power is still present from 2 other sources.

I would E-mail them back saying that you recommend disconnecting the set-up as it stands now and have it wired in correctly.

 

[Spoon]

However, so long as a suitable legend in accordance with 16.1, and he's used appropriate orange wiring that is separated from other circuits in the main panel.

No legend or orange cable used, as far as I know.

 

[Spoon]

As you have expressed, this set-up doesn't comply with both the BS7671 nor the BS60204, why can't you run the grease units of the press supply itself and just intergrate it into the control system, at present you have 3 seperate supplies running through one control system and also it means an inherent risk to any maintenance who isolate the press power upstream could be at risk they are not aware that power is still present from 2 other sources.

I would E-mail them back saying that you recommend disconnecting the set-up as it stands now and have it wired in correctly.

My Group Installation Manager sent me the marked up sketches, asking me to update the drawing. I have told him that I'm not willing to do that as they are against the regs. Have also asked who authorised the changes. Things have gone a bit quite for now. Just gatherings some ammo to use later on.

 

[Darkwood]

However, so long as a suitable legend in accordance with 16.1, and he's used appropriate orange wiring that is separated from other circuits in the main panel.

There is no need to change it, only a recommendation from 60204.

This option would depend on how the 2 grease circuits are fitted to the press, E-stops or Isolation for maintenance been of concern, using orange cabling within control systems usually denotes power that is not isolated with the main Isolation point and can relate to internal cab' lighting or external control links but doesn't usually associate with bringing in LV seperate power circuits like above.

 

[Darkwood]

Personally if there exists no risks or confusion of the grease units been seperate from the press control system then you would probably run each grease unit supply to its own little control box, you would then establish a global start/stop circuit that would interlink between the control boxes (in pretty orange colours) where the control power is derived from the main press control supply.

This way isolation of the press control drops out power on the global start/stop circuit, thus power to the grease units cannot be established, stopping of the press also drops out the power to the grease units and all that is needed then is appropriate marking of grease control boxes and where they can be isolated and caution or steps taken to make any dangerous interlinking low voltages be run through the controls with finger safe options and clearly marked up or a SELV approach taken for extra safety.
The exact requirements depends alot on the existing set-up and may vary slightly but its a general shot in the dark to an appropriate method.

 

[Darkwood]

Just to add, simple changes can make the set-up safer and rather than having 2 seperate supplies to each press then fit a double pole mcb and run them both to one control box, spending £20 on a DP mcb may save £100 on a seperate control box and contactors etc.

 

[Spoon]

This is the thing darkwood. This could have been done controlled locally to the grease system by fitting a contactor to each system and controlling it with a 24v signal from the drive cabinet. That way you don't have to alter the existing controls. I'm surprised the grease systems don't have a start/stop signal anyhow. We have no manual or any paper work for these.
Lack of info from site....

 

[Bobster]

This is the thing darkwood. This could have been done controlled locally to the grease system by fitting a relay to each system and controlling it with a 24v signal from the drive cabinet. That way you don't have to alter the existing controls. I'm surprised the grease systems don't have a start/stop signal anyhow. We have no manual or any paper work for these.
Lack of info from site....

This maybe true, but now the work has been done. Your company bear responsibility for the safety of it.

 

[Spoon]

This maybe true, but now the work has been done. Your company bear responsibility for the safety of it.

Yes, I know. That is why I want it done properly. I'm hoping it's just a bad sketch and whoever did the change will tell us its all done correctly.

 

[Darkwood]

I dare say it took more work and materials to do it as suggested in the wiring diagram than it would have by intergrated it into the existing controls, the further the DB was the more time and money has been wasted through someone doing this work without knowledge of the what he is doing, functional does not mean safe and/or compliant.