Sorry, no coffee yet. I should have wrote...

Often the basic test voltage 1250VAC is applied from input to
ground (chassis) and the double insulation test voltage of
2500VAC is applied from input to output. Because the output
is not tied to the safety ground.


Grumpy The Mule wrote in
:

Often the basic test voltage 1500VAC is applied from input to
ground (chassis) and the double insulation test voltage of
2500VAC is applied from input to output. Because the output
is not tied to the safety ground.