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AC and DC isolators

DC Isolators

These DC isolators from Kraus and Naimer are designed specifically for PV installations. With interlocked lids (the lid cannot be removed if the switch is in the 'on' position), padlockable switches, and IP66/67 rated enclosures, they are an excellent, safe choice - and for a quality switch from a European manufacturer, remarkably well priced.


The KGD40 can cope with up to 50A at 1000V and new permanent magnet technology in the contact body greatly reduce arcing time, improving safety standards. They are also non-polarity sensitive.


The ratings given in the table below are in accordance with the requirements of IEC/EN 60947-3, utilization category DC-21B. Ratings in accordance with DC-21B are suitable for use in the selection of an isolator to isolate a PV string input to a PV inverter.

DC 21B Ratings

450V 500V 650V 800V 920V 1000V Product Code
25A 21A 20A 18A 11A KG20 T104/D-P003 KL51V
25A 23A 15A 12A KG32 T104/D-P003 KL11V
30A 30A KGD40 TD102/D-P003 KL11V
40A 40A 30A 20A 20A KGD40 TD103/D-P003 KL11V
50A 50A 40A 40A 30A 30A KGD40 TD104/D-P003 KL11V
50A 40A 40A KGD40B TD106/D-P003 KL11V
50A 50A 50A KGD40B TD108/D-P003 KL11V

AC Isolators

Traditional rotary-switch isolators also from Kraus and Naimer offer excellent value.

We also have larger isolators for the higher current three-phase installations.