This is the digital module "ANSI 51 - IDMTL overload protection" for Micrologic X trip unit on MasterPact MTZ offer. A digital module is an advanced function that can be uploaded in Micrologic X trip unit at any stage of the product life cycle. Digital modules allow you to customize MasterPact MTZ circuit breaker to your specific needs. The digital modules are available 24/7 on the Schneider Electric GoDigital store (godigital.schneider-electric.com). The upload of the digital modules is made without interrupting power, using EcoStruxure Power Commission software and a USB cable. This digital module provides overcurrent protection based on one of the selected IDMTL tripping curve IEC 60255-151 (DT, SIT, VIT, EIT, HVF). Long-time overcurrent protection (ANSI 49RMS/51) remains active when IDMTL overcurrent protection (ANSI 51) is configured. IDMTL overcurrent protection (ANSI 51) is based on the true RMS current with thermal memory. This protection is implemented independently for each phase and the neutral. The IDMTL overcurrent protection requires the Micrologic X control unit to be supplied by an external 24 V dc power supply. The Micrologic X control unit firmware (greater than or equal to V003.000.xxx) is compatible with this digital module. Earlier firmware versions need to be upgraded. SIT or VIT tripping curve improves selectivity with an upstream low voltage protection relay where the long time protection is set at very low level. HVF tripping curve improves selectivity with upstream fuses (High Voltage Fuse). DT tripping curve improves protection with certain types of loads where the level of short circuit is very low.