The LV836300 is an ESM (Expansion Safety Module) I/O expansion module in the MasterPact range, designed as a safety logic controller for ERMS (Earth Return Management System) applications. It mounts on fixed MasterPact MTZ1, MTZ2, or MTZ3 air circuit breakers, providing a single NO signal contact rated at 3 A at 110 V AC and 3 A at 24 V DC. The minimum load it can reliably switch is 10 mA at 5 V DC, which matters when the downstream logic input has a low wetting-current requirement — below that threshold, contact oxidation can cause intermittent opens in a safety circuit.
Integration into the safety chain
This module sits physically on the breaker's fixed cradle, not on a separate DIN rail — the panel layout must allocate space for the MTZ frame itself, with the ESM occupying the accessory slot. The 1 NO contact is typically wired into the ERMS control loop, where the safety logic controller monitors the breaker position and earth-fault status. Because it's a safety logic controller, the contact output should be treated as part of the protection chain: verify that the 3 A rated operational current is adequate for the coil or input it drives, and that the 10 mA minimum load is below the lowest expected switched current to avoid contact film issues over the unit's service life.