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This month I'm building a remote lab for specialist chemistry work, in a self-contained 'Portacabin' type building.
The cabin will have a new, Hager 3 phase board, with an 30mA RCCD main switch. It's only a single small room so I'm not bothered about the possibility of the whole installation tripping (one of the ceiling lights will be an emergency unit).
As the building's portable, its Hager board will be supplied from a 32A IP67 5-pin appliance inlet on the outside wall.
This will be fed from a new local external power post with a 5-pole IP67 32A socket. A short rubber extension lead completes the connection.
Here's the problem: How do I supply the power post? As it's outside, with a 400V socket continually being rained on, 30mA protection feels like a good idea. But then there would be two RCDs in series. Not good.
And if I do protect the power pole socket at 30mA, there's no real need for the upstream protection in the cabin. But then any tripping would mean a walk back to the potentially locked building where the main DB is.
I want the flexibility of 'plugging in' the cabin, so don't want to hard wire anything.
Is there an obvious solution? Am I missing something?
The cabin will have a new, Hager 3 phase board, with an 30mA RCCD main switch. It's only a single small room so I'm not bothered about the possibility of the whole installation tripping (one of the ceiling lights will be an emergency unit).
As the building's portable, its Hager board will be supplied from a 32A IP67 5-pin appliance inlet on the outside wall.
This will be fed from a new local external power post with a 5-pole IP67 32A socket. A short rubber extension lead completes the connection.
Here's the problem: How do I supply the power post? As it's outside, with a 400V socket continually being rained on, 30mA protection feels like a good idea. But then there would be two RCDs in series. Not good.
And if I do protect the power pole socket at 30mA, there's no real need for the upstream protection in the cabin. But then any tripping would mean a walk back to the potentially locked building where the main DB is.
I want the flexibility of 'plugging in' the cabin, so don't want to hard wire anything.
Is there an obvious solution? Am I missing something?
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