Variable frequency speed single girder overhead travelling crane in the installation, commissioning, use and maintenance process, it is necessary to strictly comply with the following precautions, otherwise it will form personal injury and equipment damage.
After the power is applied to the control system, commissioning and maintenance personnel in the operation is necessary to be very careful. After disconnecting the power supply, the inverter charging indicator can only touch the components in the cabinet after it has subsided. It is forbidden to connect the input power to the inverter output terminals u, V and W, otherwise the inverter will be burned. It is forbidden to ground the insulation resistance between output terminals u, V and w, otherwise the inverter will be damaged. It is forbidden to measure the insulation resistance between the output terminals u, V, w or to ground with a megohmmeter, or else the inverter may be damaged.
When a frequency converter control multiple parallel motors, such as single girder overhead crane operation organization, it is necessary to heat the relay between the frequency converter and each motor, the contact of the relay should enter the control circuit in order to suspend the operation of the frequency converter when a certain motor, to maintain the motor overheating. When the lifting organization uses the inverter to control only one motor, because the inverter has a variety of maintenance functions such as overcurrent, overheating, and so on, and therefore do not need to set up a thermal relay.
The thickness of the steel plate used in the manufacture of single girder overhead cranes is generally 6-12mm, plus the negative public service of the steel plate itself. Thus, the rust layer on the single girder overhead travelling crane should not be ignored. Together, the appearance of the oxide layer and rust on the crane's painting life also has a great impact, because the rust layer and oxide layer is simple to fall off, so if you do not eradicate the oxide layer and rust layer before painting, the back of the paint will appear oxide layer flaking, flaking, peeling, etc. FF, not only affect the crane's beauty, and. As a result, the steel exterior loses maintenance and further rusts, posing a threat to the structural safety of the crane.
After the wiring of the inverter is completed, the correctness of the wiring of each line should be checked first. Under the premise of ensuring correct wiring, first cut off the power supply of each organization's inverter, and then connect the total power supply. Check the correctness of the main control circuit, limiters, auxiliary power supply, lighting power supply and other auxiliary power supplies, and connect the power supply of the corresponding organizations in turn, and debug the inverter and its speed control system.
The main structure of the single girder overhead crane is a steel structure welded parts, commonly used manufacturing materials are steel plates, sections, etc. These materials are generally purchased from the steel market, there will be a layer of rust. Rust is caused by the oxidation layer formed when the exterior reacts with oxygen and water in the air.
The steel for manufacturing single girder overhead cranes is pretreated before welding, i.e. the exterior finishing reaches Sa2.5 specification. In order to satisfy the requirements of crane spraying rust removal grade and exterior roughness, manual rust removal cannot satisfy the requirements. It is necessary to use spray method, i.e. dry sandblasting, shot blasting and shot peening. The longest of the three methods is shot blasting. After shot blasting, the steel exterior should be coated with anti-rust primer within 2 hours. Epoxy zinc-rich primer is the commonly used primer in China. The primer has little effect on the subsequent welding of the steel and maintains the steel exterior for a longer period of time.
