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A question regarding the use of a mccb as a 3 phase main isolation switch to a DB.
Is it a necessity?
Current set up is I have a 3 phase 70mm supply feeding a DB.
The origin of this supply is unknown, hence I’m getting northern power out to investigate as the main cut out earthing arrangement and metering is unknown
As I do not know the primary OCPD protecting the 70mm swa and lets assume for the minute that they are adequately protected via bs 1361 or bs 88 fuses, is the mccb totally necessary protecting the DB final circuits?
The existing one is broken and does not isolate the DB.
Spoken to Hager and the range is now obsolete and can’t be retro fitted.
It’s a 250 amp mccb with its In set to 200 amp minimum setting so it’s rated to high for the 70mm swa anyway.
Comments welcome:mtongue:
Is it a necessity?
Current set up is I have a 3 phase 70mm supply feeding a DB.
The origin of this supply is unknown, hence I’m getting northern power out to investigate as the main cut out earthing arrangement and metering is unknown
As I do not know the primary OCPD protecting the 70mm swa and lets assume for the minute that they are adequately protected via bs 1361 or bs 88 fuses, is the mccb totally necessary protecting the DB final circuits?
The existing one is broken and does not isolate the DB.
Spoken to Hager and the range is now obsolete and can’t be retro fitted.
It’s a 250 amp mccb with its In set to 200 amp minimum setting so it’s rated to high for the 70mm swa anyway.
Comments welcome:mtongue: