Our air compressor trips off immediately after it powers on. Is this a mechanical or process issue?Jun-2021
Anant Chourikar, HCL Technologies Limited, firstname.lastname@example.org
Typically, it happens because of the motor overload due to very high starting current. It happens in centrifugal pumps as well if discharge valve is open and pump is started due to heavy current. Kindly check for compressor valves or mechanical interlocks which overloads the motor.
Elkin Anaya, KBC, Elkin.Anaya@kbc.global
There are different types of air compressors with different control systems and process configurations. Let us assume we are dealing with a process air centrifugal compressor which has been in operation for several years and trips off after it powers on.
In this case, the issue could be caused by the control system and motor protection. This type of unit starts with minimum load and as the compressor delta P increases the control system increases the load until reaching operating conditions. Most air compressor motors are not sized to start with the full load. If the valve controlling the load malfunctions, the unit would start with a full load, causing motor overload, which would trigger the motor overload protection to shut off the unit. Therefore, the issue is not related to a compressor mechanical problem. It is due to a combination of process conditions, load valve malfunction, and motor protection.