Heater identification
The 1SAZ721201R1031: As a thermal overload heater it pairs with a contactor to form the thermal element of a motor starter — current through the heater bends the bimetal strip, and the auxiliary switch then drops the contactor coil on sustained overload. The setting range is the number the MRO and the panel specifier both act on, because the heater's job is to sit at the motor's full-load current and not above it.
Setting range drives fit
The 1.7-2.3 AMP SETTING RANGE sets the band the heater sits in for thermal overload pairing with a contactor. Matching that range to the motor nameplate FLA is what avoids nuisance trips on start and stops a real overload from passing unchecked.
Stocking and adjacent heaters
Stocking placement belongs with the matching ABB contactor frame; the setting range is keyed to the bimetal geometry and is not adjustable across families. Adjacent codes 1SAZ721201R1043 and 1SAZ721201R1028 in the Thermal Overload Heaters for Starters line serve as MRO min/max alternates for motors whose FLA lands a band away.