Contactor K3-74K00-230V-75,00kVAr

The SCHRACK K3-74K00-230V-75 kVAr  contactor features high-quality, robust construction and is designed for installation in low-voltage, three-phase networks. These contactors can be equipped with auxiliary contact blocks. Installed auxiliary contacts with damping resistors (pre-contacts) provide:

• 4 HN.. or HA.. snap-on
• 2 HB.. on the left or right side and 7 HN.. or HA.. snap-on
• 2 HB.. on the left or right side and 4 HN.. or HA.. snap-on

Considerations:

• Minimum conductor cross-section under maximum load
• Maximum thermal current: Ith 130A

Type Specifications:

• Type 230 for AC and DC operation at 220-240 V, 50/60 Hz, and 220 V DC (with integrated coil suppressor).
• Type 230VS for AC operation at 220-240 V, 50 Hz (with integrated coil suppressor).

The auxiliary contacts ensure:

• Reduction of switching current surges to <70xIn,
• Protection of capacitors from current surges (which can typically reach up to 200xIn),
• Prevention of contact erosion,
• Overall improvement in current and voltage stability within the network, thus extending the lifespan of components.

Application

These contactors utilize a two-stage switching mechanism, achieved through auxiliary contacts. This design prevents arcing and subsequent welding of the main contacts, as was common with older contactors (e.g., V100, V13). Unlike conventional contactors, they also reduce transient phenomena that propagate through the network and can interfere with communication systems (telecommunications, PC networks).

Design

Auxiliary contacts (pre-contacts) are located on the contactor body and switch a few milliseconds before the main contacts. Using series-connected resistors, current surges are dampened to as low as 70 times Ie.

Due to their construction, these contactors are designed for high switching frequency and long service life, enhancing the reliability and lifespan of the entire compensation device. An added advantage is the high switching capacity of up to 100 kVAr. The contactor can be equipped with auxiliary contacts (NO, NC) for purposes such as remote communication. Installation options include DIN rail or screw mounting.