16A socket board fitted with non ISI marked 1.5 sq mm wire.
As per standard 1.5 Sq mm is not advisable for 16 Amps socket. Additionally Non ISI marked wires are less fire resistant and have tendency to melt with high loads. They also do not have good insulation. Non ISI marked wires could have less longevity, are less safer and ecofriendly as compared to ISI marked wire. So, it is better to have ISI marked wires which will be a step towards safer home and also would be better in longer run.
We recommend to provide ISI marked wire with required gauge as per standard.