The Ministry of New and Renewable Energy (MNRE) on August 12, 2026, invites comments on the Draft Specification of Solar Pump Controllers.
The following has been stated:
• The Draft proposes detailed technical, safety, performance and monitoring requirements for solar pump controllers used in agricultural applications. The draft requires controllers to be capable of continuously delivering their declared rated power/current for at least 2 hours without tripping or overheating, and the controller rating shall be equal to or greater than the peak power of the connected PV array. Controllers shall incorporate Maximum Power Point Tracking (MPPT) to optimise power extraction despite changes in solar irradiance, temperature and module conditions. The proposed efficiency requirements are stringent, with static MPPT efficiency of at least 98%, dynamic MPPT efficiency of at least 97%, and minimum overall system efficiency of 90.2% for controllers below 5 HP and 91.2% for controllers of 5 HP and above at the specified operating conditions.
• The draft also prescribes motor-control and power-quality requirements. Controllers shall support suitable control techniques such as V/f or flux control and provide stable operation from zero to rated speed. A Universal Solar Pump Controller capable of operating agricultural equipment other than pumps shall withstand 150% torque overload for 30 seconds and shall provide selectable load outputs with proper electrical interlocking. For sinusoidal output, voltage THD shall not exceed 10%, with no individual harmonic exceeding 6% of the fundamental; for intentionally non-sinusoidal outputs, THD shall not exceed 40%, while voltage transition slopes and peak voltage are also controlled. For 415 V systems, motor-terminal voltage spikes after cables exceeding 60 metres shall not exceed 620 V and shall have a duration below 1 microsecond.
• For electrical and environmental safety, the proposed specification requires adequate protection against electric shock, insulation withstand and insulation resistance testing in accordance with IS 16221 (Part 1):2016. Following humidity preconditioning, leakage current shall not exceed 5 mA, insulation resistance shall exceed 100 MΩ at 500 V DC, and touch-current limits are prescribed. Stored electrical energy shall also discharge to below 60 V within 10 seconds after PV disconnection. The draft further introduces mandatory marking, display and remote-monitoring requirements. Controllers shall carry permanent, weatherproof rating plates containing manufacturer details, model and serial number, manufacturing date, PV voltage/current and power ratings, MPPT range, motor ratings, supported motor types, IP rating, pollution degree and overvoltage category. Mandatory safety warnings include instructions to disconnect PV supply before servicing, protective-earth identification, hot-surface warnings and hazardous DC-voltage warnings where applicable.
• The last date to submit comments is August 28, 2026.
[Notification no. - 313-12/2/2026 -S&QC]
