A non-isolated circuit is one not shielded from the AC power source, which makes electrocution possible. This type of design is mainly for double-insulated products, such as LED replacements for bulbs, in which the LED and the whole product are integrated and sealed in the non-conductive plastic, making the light fixture safe.
Usually, the driver efficiency of non-isolated driver can reach 91% or more, which is higher than isolated driver whose driver efficiency is usually around 88%. Due to the absence of isolation transformer, non-isolated driver cost less.
As mentioned above, the structure of the non-isolated driver makes the electrocution possible, so as to guarantee the safety of the lamp adopting this type driver, the lamp shell must be insulation. Besides, non-isolated driver has poor performance in surge, thus leading the driver a bad choice for outdoor lighting fixtures.