External (exposed but OK) location of pump. Appliance cable is 1.5 sq mm 2 core and a separate earth lead ( damn! separate issue.)

What power supply cable size should I run to the power outlet for the pump?

Suggested rating of combination CB and safety cut (combined)?

Approx 12 metres from supply board. Will be dedicated circuit.

Run it as a regular outlet, 2.5mm² on a 20A breaker.

Use a 20A/30mA RCBO if you're likely to be plugging garden tools into the outlet at any time.

Thank you for the information. The supply is good!

Of course changing the pump cable myself invalidates the warranty but think that safety is a higher consideration. Contacted the pump manufacturer and they refused to give details stating that Thai Standards don't allow for a three lead cable of 1.5 sq mm wires, two core cable is OK they refused information on the process of replacing the cable stating it was against their policy to give out manual's procedures. The access is hidden under the pump itself. I finally contacted the retailer (bigpump)for instructions and K. Piya was most supportive and made contact with the Thai distributor.

The engineers from the distributor factory arrived within 24 hours and replaced the cable onsite, free of charge, with a Thai molded cable and standard 3 pin plug with 3 x 1.5 sq mm leads all round, EU colour coding. The warranty remains valid.