Installing Mitsubishi inverter FR-E520S-2.2K-EC

[Colin Barron]

I have purchased a single phase 240v 2.2kw inverter and the instructions say use a 30AF 30A 2 pole magnetic circuit breaker. What is the benefit of 2 pole as opposed to a single pole in the live wire? Single pole are much cheaper. Also what does 30AF mean?
Thanks
Colin

[GeorgeD]

Also what does 30AF mean?

30Amp Fuse. :smile:

[Colin Barron]

30Amp Fuse. :smile:
The diagram shows a 30A mcb and a contactor after it. maybe when they put 30af 30a they were giving an option of a fuse instead of a 2 pole mcb which is quite expensive?
Also would it be ok just fitting a single mcb in the live input instead of an expensive 2 pole mcb
Thanks
Colin

[irving2008]

30AF means its a 30A 'frame' even though it might be fitted with say a 16A breaker. A 30A breaker in a 30A frame cannot be upgraded to bigger, but thats probably not an issue here.

Brekaers come in various types depending on their overcurrent trip rating... you need a Type C for motors (trip at 5 to 10x rated current) and these will usually need to be mounted in a small consumer unit. Do not get confused between an MCB (overcurrent) and a single pole RCD (residual current) although you can get them combined as an RCBO.

Under more recent wiring regs (at least the last 10y I think) it is necessary to break both live and neutral lines for fixed circuit breakers which are also used as isolating switches, single pole breakers are only now allowed for fuse replacement in legacy units or when used on a subcircuit and protected by an overall dual-pole master breaker and isolating switch as in a modern consumer unit. The regs here are quite complex. I beleive a single pole MCB is acceptable as long as it is in a unit with an dual pole isolating switch.

[GeorgeD]

Search ebay for a Dpole 30amp,there's 2?

[GeorgeD]

http://cgi.ebay.co.uk/MK-LN-6348s-RCBO-B-32-30ma-RCD-MCB-6-ka-2-POLE-DOUBLE-/280565016401?pt=UK_BOI_CircuitBreakers_RL&hash=item4152fa6751