5 - Use of Lock-out Equipment

Question 1

The ability to identify and explain the different types of pad-locks used under WTSR.

Answer 1

As stated in the MAN WTSR IMPLEMENTATION MI P0 there are…

Safety Lock/Keys
- Red in colour
- Used by the AT for Isolations
- Must be insulated for electrical isolations
- Only one key to prevent the isolation being removed by anyone other than the AT – This key will be placed in the lock box and all members of the team will apply their personal locks to the lock box. This prevents any access to the box without having everyone else’s consent – Safety measure
Personal Locks/Keys
- Blue in colour (Sometimes yellow for contractors is responsible manager deems it necessary)
- Used by all personnel working on Plant/LV apparatus
- Used by all persons in the party to secure the lock box
Control Lock/Key
- Red in colour
- Used by the AT in order to surrender the AWP to another AT – All personal locks will be removed prior to handover
General Safety Lock/Key
- Orange in colour
- Used by AT/CT and required as stated on the AWP or ROP – Key then retained by the AT/CT
- Used at the HV SCADA switch to prevent SCADA from operating the switchgear

Why the different colours?
The difference in colours determines who holds and uses the lock/keys and their uses. For example, an AT will control the red locks (Safety locks – for Isolations, Control lock – for lock box (Surrendering)) and CT’s/contractors will possess the blue (or yellow) personal locks (to secure the lock box.

Question 2

The ability to identify and use the correct type of lock-out equipment for any isolation point found in the WTG.

Answer 2

Can be Used

• Padlocks
• CB/RCD hasps
• Caution notices
• Caution tape

If the device can’t be isolated
The AE must be informed and with consultation from the responsible manager must investigate alternates to lock-out the device. This could be the isolation of an upstream device or a specialist manufacture.

Question 3

The ability to define the term “Safe Custody” and what type of Safe Custody may apply.

Answer 3

Safe Custody during work on the WTG

• Prior to their use, safety locks/keys/isolating devices must be kept within the workplace and remain with the AT
• Safety key/devices will remain in safe custody within an approved lock box
• AT will secure lock box with the control lock and retain the control key along with AWP until removal of safety precautions

Safe Custody on WTG when work is temporarily suspended
- When AWP is surrendered temporarily and the AT remains on WTG, safe custody will remain with the AT

Safe Custody off the WTG

• When work stretches beyond a working day, the AWP will be surrendered
• All personal locks removed from lock box leaving only the control lock on the box
• AWP, control lock key and associated documents shall be returned to either the Deputy Commissioning Manager/Service Supervisor or nominated AT at the site and will be secured until required
• Arrangements for safe custody will be decided locally by each site i.e. a lockable cabinet, key safe or drawer to retain AWP, control lock key and documents

Question 4

The ability to explain and identify the correct use of Caution Notes and markings.

Answer 4

Caution notices always to be used with a safety lock.

MVOW WTSR POI Caution Notice
-	SSoW – WTSR
MVOW WTSR CRofHVCB Caution Notice
-	SSoW – WTSR
MVOW WTSR Caution Tape
-	SSoW – WTSR
MVOW ENSR POI Caution Notice
-	SSoW – ENSR
MVOW ENSR CME Caution Notice
-	SSoW – ENSR
MVOW ENSR Danger Notice
-	SSoW – ENSR

Question 5

The ability to demonstrate the use of a Lock-out box.

Answer 5

After identification, isolation and testing of POI…

• The ‘precautions’ section of the AWP must be signed, timed and dated
• All keys, fuses, isolation devices relating to the AWP must be placed into the lock box
• Each member of the working party will then apply their personal locks to the lock box and retain their own key in safe custody
• The AT will apply a control lock and retain the key
• The individual locks MUST remain in place at all times, unless carrying out a ROMP or the POI is required as specified in the AWP

When performing a ROMP

• After the work has been carried out to the point of a ROMP all work shall stop
• The working party will remove their personal locks from the lock box
• The party will move into a safe zone as specified/agreed by the AT
• The AT will remove the control lock, remove isolations, date and sign when the isolation is removed and then get ready for testing
• After testing, isolations will be reinstated, control lock applied, personal locks applied and the AWP will instruct on further steps