A 3kva buck-boost autotransformer is connected to raise the voltage from 208 to 240 for a 7 1/2 HP motor.
Autotransformer manufacturers tables indicate a 1 kva would be sufficient, but as discussed in my previous post, the 3 kva unit will be OK.
Article 450-4 requires OCPD installed on the input conductors at a maximum of 125% of full load xfmr input.
The original installer fused only the output side.
If I fuse the input according to manufacturers tables (maximum 40 amp), I assume that secondary protection is still required, but I am not sure because of the common connection.
Thanks for the help.
[This message has been edited by Redsy (edited 02-13-2005).]
