Are you sure about the 4 markings.
To me you need 1'supply live' going into the unit,then through fuse
2'load live' going from unit to appliance
3'load neutral' from appliance back to unit
4'supply neutral' going from unit, back to fusebox.
1 & 4 are within the supply cable
2 & 3 are within the appliance or load cable.
You mention a second 'live' which could exist on a switched fcu where a switched 'live' is sometimes catered for.
More important you do not mention the 'supply neutral' and without this the electrical circuit is incomplete and cannot function.
If you need to find a tradesperson to get your job done, please try our local search below,
or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Please select a service and enter a location to continue...
Are you a trade or supplier? You can create your listing free at DIYnot Local