1.5mm or 2.5mm, 3 core SWA cable

[saveasteading]

I asked the Marsh rep what cable we needed and he said "Generally, a 2.5mm 3 core armoured cable will need to be ducting out to the tank."

 

He also attached the installation manual which says "A single run of 1.5mm (or greater dependent on distance/voltage drop considerations) 3 core SWA cable".

and "Cable protection via 10amp MCB/RCD or RCBO, rated 230V AC and tripping current 30mA."

 

 

The length of cable will be about 25m from fuse board to tank.

I don't know what power the pump draws to make air bubbles but I seem to recall it is under 100W.

 

It's only worth about £15 difference in cable. But put it another way and it is 20% and wouldn't that be nice through the whole job.

Plus the skinnier one will be easier to manipulate.

 

And does it really need a duct? I was planning to put it in the drain trench. 

 

Electricians' advice welcomed.

 

Edited 4 hours ago by saveasteading