Cause Analysis and Methods of Eliminating Unstable Rotation Speed of Diesel Generator Set

The unstable speed of diesel generators is also called traveling or surging. Such failures will not only affect the actual power supply effect of the diesel generator set, but also reduce the life of the diesel generator parts, resulting in the reduction on the lifespan of the diesel generator. The main reasons for the unstable speed of diesel generator sets are oil circuit failure, governor failure and fuel injection pump failure. Generator manufacturer-Dingbo Power Dingbo Power will analyze for you one by one as following.

1. Oil circuit failure

(1) The low-pressure oil circuit is blocked and the oil supply is not smooth. The elimination method is to clean and unblock the low-pressure oil circuit.

(2) Insufficient fuel in the fuel tank or blockage of the vent of the fuel tank cap causes insufficient fuel supply. Remedy add enough fuel and dredge the vent hole of the fuel tank cap.

(3) The oil pipe is cracked, the pipe joint is loose, etc., causing the low pressure oil circuit to enter the air. In addition, the wear and tear of the hand oil pump of a multi-cylinder diesel engine can easily cause the oil circuit to enter the air. The troubleshooting method is to replace the oil pipe and hand oil pump, and tighten the pipe joints.

(4) The sealing performance of the outlet valve of the fuel injection pump becomes poor or the positioning screw is loose. Remedy: Grind the delivery valve and tighten the positioning screw.

(5) The fuel injector works unstable. Remedy: Replace the needle valve assembly of the injector.

2. The governor failure

(1) The elasticity of the speed control spring is weakened. Insufficient spring force will reduce the speed governor's speed control sensitivity and increase the stable range of diesel engine speed. At this time, the speed regulating spring should be replaced.

(2) Excessive wear of the oil pump oil volume adjustment arm and the fork groove of the speed control lever, the excessive wear of the cone surface of the drive plate and the thrust plate, etc. will cause the adjustment of the governor to lag and cause traveling. At this time, the worn parts should be replaced to restore the normal fit clearance.

(3) Poor internal lubrication of the governor or excessively dirty or thick oil in the governor or damage to the surface of the moving parts causes seizure, which hinders the movement of moving parts, lags behind the speed regulation, and causes unstable diesel engine speed. The troubleshooting method is: clean the interior of the governor with diesel, replace the oil in the governor, repair or replace damaged parts.

3. Fuel injection pump failure

The wear of the plunger pair, the delivery valve pair, and the roller of the multi-cylinder diesel engine causes the fuel supply pressure of each cylinder to be inconsistent, and the improper adjustment of the fuel injection pump will cause the fuel supply inconsistency. At this time, it should be re-adjusted on the test bench. In addition, a cylinder head gasket of a multi-cylinder diesel engine is burnt, poor valve sealing, excessive wear of the piston ring, etc., resulting in poor compression or failure of the cylinder, which will make the diesel engine speed unstable. The solution is to replace the cylinder gasket, piston ring and grinding valve.

The above is the reason analysis and troubleshooting methods of diesel generator set speed instability organized by Guangxi Dingbo Electric Power Equipment Manufacturing Co., Ltd. For generator sets, maintaining a reasonable speed can effectively reduce the wear of the components of the generator set and extend the use of the generator set. Life, so when you find that the diesel generator set has unstable rotation speed, you must stop it for maintenance in time; if you have any questions about the diesel generator set, please write us at dingbo@dieselgeneratortech.com.