Contactor technical parameters
1. Rated Voltage (1) The rated voltage on the contactor's nameplate refers to the voltage applied across its main contacts. For DC contactors, common ratings include 110V, 220V, 440V, and 660V. AC contactors typically have ratings such as 127V, 220V, 380V, and 500V. If you're controlling a 380V three-phase induction motor, it's essential to select an AC contactor rated for 380V. (2) Rated Operating Voltage The rated operating voltage is the voltage value that determines the contactor’s performance along with its rated current. Parameters like contact capacity, breaking capability, working system type, and usage category are all influenced by this voltage. In multi-phase circuits, the rated voltage refers to the line-to-line voltage of the power supply. Contactors can also be specified with multiple sets of rated voltage and current based on different working conditions and usage categories. For example, the CJ10-40 AC contactor has a rated motor voltage of 220V (capable of controlling up to 11kW) and 380V (capable of handling up to 20kW). (3) Rated Insulation Voltage The rated insulation voltage is a nominal voltage used in dielectric testing and for determining clearance and creepage distances. Unless otherwise stated, it represents the maximum operating voltage the contactor can handle. Importantly, the rated operating voltage must never exceed the rated insulation voltage to ensure safe operation. 2. Rated Current (1) The rated current on the contactor’s nameplate refers to the current that the main contacts can carry under normal operating conditions. For DC contactors, typical values range from 25A to 600A, while AC contactors usually go from 5A to 600A. These values assume the contactor is mounted on an open control panel, the contacts don’t exceed their rated temperature rise, and the load is intermittent. The term "intermittent-long-term" means the contactor is energized for no more than 8 hours at a time. If it runs longer, it should be de-energized and operated at no load at least three times to remove surface oxidation. Adjustments may be needed depending on these conditions. When installed inside a cabinet, the current rating is typically reduced by 10–20% due to poor ventilation. If the contactor operates continuously with a duty cycle below 40%, it can handle a slightly higher current—up to 10–25% increase if it's installed in an open environment, or 5–10% if in a cabinet. Adjustments should be made based on specific installation conditions. 2. Rated Working Current (1) The rated working current of the main contact is determined based on the rated voltage, power, working system, usage category, and the type of enclosure. It ensures the contactor can handle the expected load without overheating or failing. (2) Auxiliary Contact Rated Current The auxiliary contact’s rated current is defined considering the rated voltage, operating frequency, usage category, and electrical life. It is generally limited to a maximum of 5A, as these contacts are not designed for high-current applications. (3) Usage Category The usage category defines how the contactor performs when controlling different types of loads. Each category has specific requirements regarding switching capacity, breaking ability, and electrical lifespan. For example, contactors used for motor control will have different specifications compared to those used for lighting or resistive loads. Double Acting Hydraulic Cylinder
A double-acting hydraulic cylinder is a type of hydraulic cylinder that has two ports for fluid entry and exit. It is capable of performing work in both directions, providing both extension and retraction forces. Double Acting Hydraulic Cylinder,Cylinder Jack,Hydraulic Cylinder Jack,Hand Pump Hydraulic Cylinder Yantai Dongyue Hydraulic Technology Co., Ltd , https://www.deeleap.com
The operation of a double-acting hydraulic cylinder involves the use of hydraulic fluid, typically oil, which is pressurized to move a piston inside the cylinder. When fluid is supplied to one port, it pushes the piston in one direction, extending the cylinder. When fluid is supplied to the other port, it pushes the piston in the opposite direction, retracting the cylinder.
This type of hydraulic cylinder is commonly used in various applications, such as construction equipment, agricultural machinery, and industrial machinery. It provides the ability to exert force in both directions, allowing for more versatile and efficient operation.