What it is and where it sits
The ABB 1SAZ421201R1002 is a thermal-overload heater pack sized for the 80-110 A current range, catalogued under Thermal Overload Heaters for Starters within the Contactors and Starters family. It mounts to a matching ABB contactor or starter to provide the bimetallic, current-driven trip element that protects a downstream motor from sustained overload — the heater, the contactor, and the overload relay base together form the motor-starter assembly a panel builder wires into the MCC line-up.
Specify it into the BOM
For the BOM line: confirm the motor nameplate full-load current falls inside the 80-110 A window this heater pack covers, and mount it to the matching ABB contactor/overload-relay base per the assembly's mechanical fit. Compliance documentation — RoHS, REACH, UL, IEC — is issued at the ABB product-family level and travels with the franchised-channel shipment; request the declaration pack with the RFQ so it lands with the heater rather than chasing it after delivery.