Isolator in the outdoor electrical box

[Rokmais]

Hi there,

I'm planning to replace the MCB on my outdoor electrical box with a better quality one, and since there is already an isolator installed by ESB Networks, as a DIY I can safely do it myself. My question is, about the isolator marked inside the orange circle. Does anyone knows what key should I use to rotate it to the OFF position and is there any safe procedure for that I should be aware before touching it?

Any advice on this would be greatly appreciated!
Thank you in advance

 

[westward10]

It isn't a key the switch knob assembly is missing.

 

[Risteard]

These are Restricted Electrical Works. You must not interfere with the Main Overcurrent Device. By doing so you will be committing a criminal offence which is punishable by a fine of up to €50,000 and/or three years' imprisonment.

Only a Registered Electrical Contractor (REC) can carry out these works.

 

[westward10]

I had a feeling this was Ireland.

 

[brianmoooore]

Is that some kind of current limiting device then? More than an isolator with a missing knob?