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The following figure shows the MPU avoidance configuration with the NEC 120% rule. There may also be situations where the site complies with a subsection of the 2020 NEC 705.12 rule other than 705.12(B)(2) or 705.12(B)(4), which Enphase Power Control uses to auto-calculate the maximum allowable backfeed current. Enphase Power Control features 35 © 2025 Enphase Energy Inc. All rights reserved. August 2025 TEB-00269-2.0-EN To account for such situations, the Enphase Installer App provides installers with the ability to define the maximum allowable backfeed current by setting the Current Limit Directly Entered parameter in the Enphase Installer App. If the Current Limit Directly Entered parameter is set, the system uses this value and does not auto-calculate backfeed current limits based on the NEC 120% rule. As shown in the following figure, the installer can directly set the PCS export current limit based on their discretion with this option. The following figure shows the MPU avoidance configuration using direct current limit input. NOTE: For safety, the Current Limit Directly Entered parameter must still comply with the NEC 705.12 rules to keep the main panel within safe limits. See Busbar Overload Control if you need to increase the backfeed current limit. For example, if a site has an Enphase Energy System and a third-party PV system connected to a main panel, the main service breaker rating is 200 A, and the main panel busbar rating is 200 A. The maximum allowed continuous current from both the PV systems is 32 A. If the third-party PV system supplies a maximum continuous current of 16 A, then the installer can manually set the maximum continuous current for the Enphase Energy System to 16 A, that is, 32 A–16 A using the Current Limit Directly Entered parameter in Enphase Installer App. The Enphase Power Control feature does not start functioning until the meters are enabled and the site is commissioned in the Enphase Installer App. If the main DER breaker has the risk of tripping before the commissioning has finished, turn off the breakers on 1 or 2 PV branches while enabling the main panel upgrade avoidance feature and turning the PV breakers back on after successful commissioning. 5.3.6 Configuring MPU avoidance through the Enphase Installer Portal Go to Systems > Activations > Configuration > PCS Export Limiting > Main Panel Upgrade Avoidance. The following figure shows the configuration screen of the Enphase Power Control feature. Enphase Power Control features 36 © 2025 Enphase Energy Inc. All rights reserved. August 2025 TEB-00269-2.0-EN