Do E Stops Need a manual reset or not

[netblindpaul]

BS 7671 doffs its hat to BS EN 60204-1.
The release of an emergency stop button must not re-initate operation of the device in question full stop.
This is also a breach under PUWER98.
The fan motor can have a local e-stop, thus must act on the control system.
It should also have a local isolator to comply with BS7671.
The control voltages etc must comply with statutory legislation.
The e-stops must comply with PUWER98.
It is dubious whether it is acceptable for an e-stop to simply control one device in a system.
For example a machine e-stop would shut down the complete machine, thus an AHU e-stop should shut down the complete system connected to the AHU as this is the button of last resort!
As a parting shot, to be an e-stop under PUWER then MUST be latching end of.
The reset, prior to start, the illuminated reset button and the reference to BS EN 418 could be a red herring dependent upon the macinery in question and the design FMEA & RA carried out by the original designer, which the installer must comply with to ensure that they comply with law.

 

[xraytek]

I have just had a look for 2006/42/EC which are the latest statutory regulations for european machinery, and have found a copy here
Page 16-17 deals with emergency stops and states the following:

1.2.4.3 "Once active operation of the emergency stop device has ceased following a stop command, that command

must be sustained by engagement of the emergency stop device until that engagement is specifically overridden;
it must not be possible to engage the device without triggering a stop command; it must be possible
to disengage the device only by an appropriate operation, and disengaging the device must not restart the​

machinery but only permit restarting."

 

[Guest123]

disengaging the device must not restart the[/LEFT]
machinery but only permit restarting."

That seems to be the winning statement.