Interference suppressor filters to protect measuring relays on frequency converters

Frequency converters are now common in many installations, and their outputs produce steep switching edges. These cause strong EMC interference and high-frequency compensating currents in connected switching components, which can disturb or even damage devices such as measuring relays. DOLD interference suppressor filters sit in the line from the converter to the measuring relay or other device being protected. They provide suppression across a wide range up to high frequencies, preventing both malfunctions and destruction of the connected equipment.

Two filter versions are listed, the MK 5130N and the LG 5130. Both are 22.5 mm wide, three-phase, rated up to 3 AC 1000 V nominal and fitted with a PE connection for a higher suppression level. They differ in depth: 97 mm for the MK 5130N and 121 mm for the LG 5130. The category also includes the OA 5640 standard probe, made of stainless steel with a PG 9 cable entry and a temperature range of 0 ... +60°C.

• Suppresses EMC interference from frequency converter outputs
• Installed between converter and measuring relay
• MK 5130N (97 mm deep) or LG 5130 (121 mm deep)
• Three-phase, rated up to 3 AC 1000 V
• OA 5640 stainless steel standard probe