UK regs for Vehicle Wash

Hi all,
I have been asked to look at refurbishing the control system of an automatic vehicle wash used in a bakery in the UK. Could any one give me some hints as to what regulations would apply to this machine.
At the moment the control voltage (including external sensors) is 110v ac I am going to reduce this to 24vdc But the motors will remain 415V ac.

I am not only interesed in the electrical regs but also regs for automated machinery.

There is only one E-stop which interupts the motor contactor control so I am going to put an e-stop on each corner controlling an E-Stop contactor so that the three phase supply to the contactors is diconnected as well as the coil control voltage. The plc inputs will remain live but all motion will stop. is this adequate?


I am bit inexperienced at this so any help would be appreciated.
cheers
ian.

ian,

Sounds like you have a good start on what needs to be done.

Make sure that the E-stop shuts off a MCR (Master Control Relay) and that this only gets turned back on when the E-stop is released and a Start pushbutton or momentary keyswitch is activated (not just releasing the E-Stop to restart the machine.)

To start an automatic cycle you may need to provide:
1. A 2 step start-up PB1 = ACTIVATE (starts a 5 second timer) PB2 starts operation & must be pushed within the earlier mentioned timers time.
2. 2-Hand buttons (to make sure both of the operators hands are clear - on the buttons.) If there are 2 operators this would require 4 buttons interlocked. This may need the 2-Step above also.

Along with your e-Stop pushbuttons, you may require a Cable-Pull E-Stop with a cable running the length of the process.

Also, you are keeping the PLC inputs active when the E-Stop is "OFF" - just make sure that the 120V power going into your PLC outputs gets interupted when the MCR is off so nothing can get power if there is any PLC failure (triacs do short out)

If there is a danger of a person entering the area you may have to have a light curtain or pressure mat for safety.

Also, above any regulations or common sfety practices: think along the lines of "Idiot Proofing" the machine, because if it is remotely possible, for some unskilled, high-school dropout operator hired by the bakery, to wrongly activate or access any operation & have his hand (or worse) removed - he will make it happen (and hire a lawyer to sue you, the bakery, the manufacturer, the equipment dealer, the installer, his trainer, Allen-Bradley [or Siemens}, etc., etc.)