Capacitive Contactor with Damping Resistor

The CJ19C Capacitive Contactor with Damping Resistor is a purpose-engineered switching device tailored for the controlled connection and disconnection of low-voltage shunt capacitors. It is a cornerstone component in automatic compensation equipment used for reactive power management. This advanced product is perfectly suited for 50Hz AC electrical systems with rated operational voltages reaching 380V, capably switching capacitor loads up to 90kvar to deliver consistent power factor enhancement. Its design incorporates a modular, stacked layout. A defining characteristic is the integration of a damping resistor circuit, configured in three separate paths, positioned strategically above the main power contact assembly. The main contacts benefit from a logical design that ensures robust and reliable operation under individual capacitive loads. To achieve its promised performance and durability, the Capacitive Contactor with Damping Resistor must be utilized within these explicit normal working and installation boundaries: a) The permissible ambient air temperature spans from -5°C to +40°C, provided that the average temperature over any consecutive 24-hour interval does not go beyond +35°C. b) The installation site should be at an altitude no greater than 2000m. c) Humidity conditions dictate that when the air temperature is +40°C, the relative humidity must not exceed 50%.

Furthermore, the average minimum temperature recorded during the wettest month of the year should be ≤+25°C, and the corresponding average maximum relative humidity for that month should be ≤90%. d) The operational environment is classified as pollution degree 3. e) The applicable installation category is III. f) Installation must be performed in an area free from significant shaking, impact forces, or vibration. g) The contactor should be mounted so that its installation surface has an inclination of 5° or less relative to vertical. The operational intelligence of the product is captured in Figure 1. The circuit diagram above the dashed line illustrates the capacitor switching mechanism, while the section below shows the connected capacitor bank. Central to its function is the integrated damping resistor circuit, which consists of early-make contacts in series with current-limiting resistors. Upon energization of the electromagnetic coil, this damping circuit closes first. The initial flow of current is thereby directed through the resistors to charge the capacitors, effectively damping and suppressing the harmful switch-on inrush current. Once this is accomplished, the main contacts close to carry the steady-state capacitor current. A critical protective feature of this Capacitive Contactor with Damping Resistor is the automatic disconnection and reset of the resistor circuit after it completes its inrush suppression task. This design greatly minimizes the opportunity for the damping resistors to overheat or fail during the capacitor disconnection phase, ensuring long-term reliability, enhanced safety, and reduced maintenance needs for your critical power quality infrastructure.

The circuit connections and terminal markings for the CJ19C type are shown in Figure 2.

The CJ19C-150 contactor has one auxiliary contact, available in two combinations; auxiliary contact combinations are shown in Table 1. Auxiliary modules can be installed on both sides of the contactor to increase the number of auxiliary contacts.

Two types of auxiliary modules are available:

LA8-DN11 (one normally open and one normally closed)

LA8-DN20 (two normally open); selected by the user when ordering.

Appearance and Installation Dimensions:

The CJ19C-150 contactor can be installed with M6 screws and lock washers, or with two 35mm mounting rails, with a center distance of 105mm between the two rails. The appearance and installation dimensions of the CJ19C-150 are shown in Figure 5.