1, what is the maximum working current? This depends on the maximum value set by the air compressor manufacturer in the PLC control system.
Whether the phase current of 2.56A is normal or not, I can tell you clearly that the current of the unit has been changing. With load, with the increase of the internal pressure of the compressor, the load increases accordingly, and finally the current also increases. The working current at 1 kg is definitely different from that at 10 kg.
3. Is there a good way to reduce the current after overload? It can only be said that you can reduce the current only after you find out the fault and solve it, or you can modify the current imbalance set in the manufacturer's parameters and increase it by several amperes.
The landlord asked these questions, is the air compressor overloaded and stopped?
Overload is actually the protection of PLC control system and automatic shutdown of the unit after the current exceeds the set value.
Then let's think about it, why does the current increase?
1, overloaded
2. Contact problem of contactor
3, the voltage itself.
To find out which problem it is, the landlord must first find out a few things.
1, when is the overload protection of the unit, and the first startup every day is still irregular.
2. When providing overload protection, what state is the unit in, such as starting and loading.
3. What is the voltage when the unit stops? The voltage of three-phase electricity can be measured by multimeter, which meets the requirements of motor.
The cold weather in winter now leads to an increase in the viscosity of lubricating oil inside the air compressor. When the air compressor is turned on for the first time every day, it will trip if the load is too heavy.
If the unit has been running and overload protection occurs under abnormal conditions, you can check whether there is carbon deposition on the contacts of the three contactors. Because of carbon deposition, the contact surface size of the contact is different, the three-phase resistance is different, and the current will be different. It is also necessary to check whether other large equipment is turned on at this stage, which leads to the voltage drop of the power grid.
There are many other factors that will be reflected in the increase of current. Here are a few simple examples.
1, replaced with a new belt, the belt was too tight, and the load increased during operation.
2. When the unit is empty, the pressure relief valve does not work, and the internal pressure cannot be minimized.
3. The internal bearing is damaged, resulting in friction during operation.
The above answers are only personal opinions. If there is anything wrong, please ask other friends to point it out.
I hope it is useful to the landlord.
Where did the landlord get the PLC control? Is there no display panel?
My personal understanding of the screw machine is basically equipped with PLC, which may not be the case if I have never touched it.
The landlord opened the electric control box to see if there were any plastic square individuals slightly larger than other things. When running, a row of small lights and several groups of small red lights are flashing. If there is, then this thing is the PLC master controller.