DC Isolator Switches for Solar PV Array Isolation | 16A-63A | Up to 1200V DC

Rooftop PV Array String-Level Isolation

On commercial flat-roof PV installations with 100-500 kW total capacity, UKP3-500V 4P DC isolators are installed in IP65 enclosures at the end of each row of modules, providing string-level isolation for maintenance crews cleaning panels or replacing module-level power electronics. The padlockable OFF position allows the crew leader to personally lock out the strings being worked on and retain the key, satisfying the site-specific LOTO procedure required by OSHA and equivalent international workplace safety regulations. The transparent IP65 enclosure cover allows the crew to visually confirm all isolators are OFF before beginning work, without opening any enclosure.

Inverter DC Input Main Disconnect

String inverters (10-100 kW) and central inverters (500 kW and above) integrate a UKP3 DC isolator as the main DC disconnect switch inside the inverter enclosure, wired between the DC input terminals and the DC bus capacitors. The IEC 62109-1 safety standard for PV inverters requires a DC disconnect device that isolates all poles of the PV source from the inverter power conversion circuit, and the UKP3 double-break per pole design satisfies this requirement with margin. The early-make auxiliary contact signals the inverter controller that the DC supply has been reconnected after maintenance, allowing the controller to execute its soft-start sequence that pre-charges the DC bus capacitors through a current-limiting resistor before closing the main DC contactor.

Battery Storage System DC Service Disconnect

Residential and commercial battery storage systems (5-100 kWh) use UKP3-500V 2P DC isolators as the service disconnect between the battery rack and the hybrid inverter DC input. This isolator allows a service technician to completely isolate the battery from the inverter before replacing a battery module or performing firmware updates on the BMS. The compact DIN-rail footprint integrates inside the battery cabinet alongside the BMS controller, and the screw-clamp terminals accept the 25-35 sq mm fine-stranded battery cable typically used for DC connections in storage systems.

EV Charger DC Input Isolation

DC fast chargers with local battery buffering use UKP3-1000V DC isolators between the battery buffer DC bus and the charger power modules. During scheduled maintenance of the power modules, the isolator provides a visible air-gap between the energized battery and the de-energized power electronics compartment. The rotary handle color coding (red for ON, green for OFF) provides intuitive status indication for charger maintenance technicians who may not be electrical specialists but need to verify isolation before accessing the power module compartment.

Solar Pumping System DC Motor Isolator

Off-grid solar water pumping systems in agricultural and remote community applications deploy UKP3 DC isolators between the PV array and the DC pump motor controller. These systems typically operate at 48-96V DC with pump motor currents of 10-30A, well within the UKP3-250V rating. The isolator provides the manual disconnect point required for pump servicing (impeller cleaning, seal replacement) without the technician needing to climb onto the roof to cover or disconnect the PV modules. The IP65 enclosure variant withstands the dust, humidity and temperature extremes of outdoor agricultural environments across sub-Saharan Africa, South Asia and outback Australia.

Specify DC Isolation for Your PV System

• Application Review: Send us your single-line diagram and we confirm the correct UKP3 model, pole count and enclosure rating for every isolation point in your system.
• DC-PV2 Test Reports: Obtain IEC 60947-3 type-test certificates for AHJ permit submissions and project technical due diligence packages.
• Sample Evaluation Program: Request pre-production samples for mechanical fit-check in your combiner box or inverter enclosure design.