Attachment - B

CB Type CB Purpose Operation

BOP MV * Common Unit Air

1. Feeder Protection Control
Switchgear 6.3 Compressor (as Protection device and CB local operation)

kV, ABB 2. Lamp Indicator

(Voltage supply, CB Closed/Open)
Unigear, * Common Flay
Ash Handling Air
Medium 3. Circuit Breaker and Earting Switch Operation Indicator
Compressor
Voltage Circuit-
Breaker (ABB
VD4)

7. CB Compartment
door

5. CB Observe
9. Operating lever for
Earthing Switch
8. Mechanical Push
button and Knob
10. Operating lever for
6. Sliding and Knob for CB racking In/Out
Insertion of the lever

4. Hexagonal shaft for Earthing

Switch operating mechanism

Operation
Opening --> Isolate De-Isolate --> Closing
Sequence to Isolate BOP MV Switchgear ( draw-out VCB from Sequence to De-Isolate BOP MV Switchgear ( draw-in VCB
Service to TEST/disconnected Position) and Earth Switch Applied : from TEST/Disconnected to Service Position) If Earth Switch
1. Check the KKS and Equipment description of VCB that Applied:
will be isolate on MV Switchgear Panel and then 1.Check the KKS and Equipment description of
Inform to CCR (Pointing and Calling) VCB that will be isolate on BOP MV Switchgear
2. Check and ensure VCB status / Equipment is in the OFF Panel and then Inform to CCR
Position by : (Pointing and Calling)
- Check lamp indicator on LV compartment door ② 2.Ensure High voltage door is close properly ⑦
and on the operating indicator ③ VCB status 3.Check and ensure VCB status / Equipment is not
is OPEN Operate/OFF by :
3. Turn the knob clockwise and hole for insertion of the - Check lamp indicator on LV compartment
lever will be open ⑥ door ② and on the opera ng indicator ③ VCB
4. Insert the operating lever for CB racking In/Ou t⑩ to status is OPEN
the hole and turn it counterclockwise to the limit - Check Earthing switch status on operating
place (TEST Position) indicator ③ is closed
5. Ensure that VCB status on operating indicator 4. Check Earth switch indicator, ensure that earth
③ is changed from Service (red) to TEST/disconnected switch position is applied (“I”) ④
Position (green) 5. Open the padlock (option) on the sliding plate of
6. Take out the operating lever and sliding earthing switch ④
plate for insertion will close automatically 6. Push the slide of the operating earthing switch
7. Contact CCR operator for check CB indicator on DCS mechanism downwards ④
or BOP PLC control room (Available indication on 7. Insert the operating lever to the Hexagonal shaft
Equipment faceplate should be missing) ⑨ of earthing switch mechanism and then
8. After confirm CB status on DCS or BOP PLC control rotate counter-clockwise by 90ᵒ gently
room. Applied padlock, caution to the knob for 8. Ensure the indicator for switch status displays
operational and insertion of the lever ⑥ “O”, earthing switch is open ④
10. Push the slide of the operating earthing switch 9. Ensure that Earthing switch status on operating
mechanism downwards ④ indicator ③is in Dis-connected/Open posi on
12. Insert the operating lever to the Hexagonal shaft 10. Take out the operating lever and sliding
⑨ of earthing switch mechanism and then rotate block of operating hole is closed
clockwise by 90ᵒ 11.Remove Padlock that applied on the knob and
13. Ensure the indicator for switch status displays “I”, sliding plate ⑥ and remove Caution notice
earthing switch is close ④ 12.Turn the knob clockwise and hole for insertion
14. Ensure that Earthing switch status on operating of the lever will be open ⑥
indicator ③is in Connected/Closed position 13. Insert the operating lever for CB racking
15. Take out the operating lever and sliding block of In/Out ⑩ to the hole and turn it clockwise to
operating hole to upwards the limit place (Service Position)
16. Lock up the Padlock with caution notice at the sliding 14. Ensure that VCB status on operating indicator
CB Type CB Purpose Operation
16. Lock up the Padlock with caution notice at the sliding 14. Ensure that VCB status on operating indicator
plate of earthing switch ④ ③ is changed from TEST/Disconnected (green) to
service Position (red)
(Isolate MV switchgear where the Earthing switch 15. Take out the operating lever and sliding
Applied is COMPLETED ) plate for insertion will close automatically
16. Contact CCR operator for check CB indicator
on DCS or BOP PLC control room (Available
indication on Equipment faceplate should be
appear)

(De-Isolate MV switchgear where the Earthing switch

Applied is COMPLETED )

Additional Information
CB Type CB Purpose Operation