The 9065SSDO18 needs to be upgraded to the current Series of overloads
Melting alloy overloads
NEMA size 5 starter with melting alloy overloads
The current Series of device uses a different overload relay.
The customer will have to convert to the Series B CT driven overload.
For melting alloy ( same overload technology as the original), the overload relay is the separate mount 9065SEO5. This will mount on the CT package part number 31102-084-50. The CT package has a 300:5 ratio and will come complete with the exception of the overload relay and thermal units.
The external reset will also have to be changed. Without knowing the enclosure, make a selection from the 9066 choices.