Danger
An electrostatic precipitator is a large, industrial emission-control unit. It is designed to trap and remove dust particles from the exhaust gas stream of an industrial process.
Such electrical equipment leaves no room for errors. Prohibiting access while the power is switched on or the equipment is electrically charged is vital.
When shutting down an electrostatic precipitator (high voltage) in a power station make sure that all main switches and earth switches are disconnected before access can be obtained through the access points (manholes, doors, etc.) to prevent death or injury to personnel.
Solution
To ensure safe operation bolt locks can be installed on all main- and earth switches and door locks to be installed on all access points (manholes, doors etc.).
In combination with a key exchange box it will not be possible to access the manholes and doors unless the complete power has been switched off.
The quantity of switches and access points may vary and is always depending on the client requirements.
Products
Bolt locks (SBL)
Door locks (SDL)
Key exchange boxes (KEB N-N)
Operation
During normal operation the main and earth switches will be switched ON while all access points (manholes, doors etc.) will be locked closed.
Switch OFF all 6 main switches and lock them by taking out all 6 keys A. Insert all 6 keys A in the earth switches and disconnect all 6 earth switches. Lock the OFF position by taking out all 6 keys B. The main switches and earth switches are all disconnected now with keys A trapped in the earth switches.
Insert all 6 keys B into the key exchange box KEB 6-3. Take out the 3 keys C.
All keys B are trapped once one of the keys C has been removed from the key exchange box KEB 6-3, consequently the power can not be connected and it is safe to start opening the access points.
To unlock the access points insert the keys C into the key exchange boxes KEB 1-30. Take out as many keys D as required and unlock the access points.
This can be done in random order. Insert the keys D into the access points and open the manholes, doors etc. The key D is trapped as long as an access point is open.
To go back to the normal operation mode the same sequence has to be mirrored.