Starting and stopping of reciprocating compressors

Personal understanding: 1. High starting torque； 2. The stable lubrication condition has not been achieved; coupled with high torque, this may cause wear of the bearing shells

Burned motor, burned bearings, damaged transmission components

Burn out the motor, damage the bearing shells, and ruin the transmission components

Burnt motor, damaged bearing shells, damaged connecting rod

Starting and stopping the compressor at full load does not necessarily cause damage to it, but each such mistake does result in some degree of damage, so it is essential to conduct inspections. Just like humans, minor illnesses don’t usually kill anyone; some illnesses aren’t even detected at all. But one day, those minor illnesses might develop into serious ones that prove fatal. Starting the motor at full load causes significant damage to it; the instantaneous starting current is very high, which can easily lead to motor burnout. Full-load shutdown causes the greatest damage to the compressor, affecting the main shaft bearings, the large and small end bearings, the crankshaft, the connecting rods, the crosshead, and the crosshead pins. Mainly, when the machine stops, the compressor stops after one or two rotations, with extremely high force

Starting under full load will result in an excessive starting current. Thanks to the current protection in place, the motor generally won’t get damaged. It’s important to be careful before turning it on, as damaging the motor could lead to serious problems

When starting at full load, the current at the moment of startup is very high; if there is motor protection in place, successful startup will not be possible. If not, 1. The inrush current at startup is too high, which may damage the motor, burn out the fuse, and cause disturbances to the power grid, leading to the shutdown of other equipment ； 2. Excessive torque at startup, combined with a lack of a proper oil film, can cause the coupling to bend, and it may also lead to severe wear on the crankshaft connecting rods in an instant ； It may be due to excessive vibration, causing the bearings and bearing shells to overheat and thus clamp the shaft ； The seal may have burned out, causing a leak ； The crosshead may have been burned and damaged ； If cranking is not performed for verification, it may cause cylinder collision and damage to the cylinders.

Pay attention to each parameter; we have a drive-side shaft here whose temperature is too high, preventing it from starting. In the end, we had no choice but to turn to the manufacturer