Diesel Generator Transformer Oil Level Too High or Too Low

When a diesel generator transformer operates in conjunction with a compensation cabinet, maintaining a normal oil level is critical. Operating personnel should regularly check the oil level gauge. If the oil level is too high (e.g., in summer), drain oil promptly; if too low (e.g., in winter), replenish oil to ensure safe transformer operation.

1. Excessively High Oil Level

The oil level may rise above the maximum line due to temperature increases, sometimes becoming invisible when exceeding the oil conservator capacity. Causes include:

Malfunctioning cooling system: High transformer temperature expands oil, raising the level. Inspect for cooling system issues such as dust blockage on coolers, unopened valves, pipeline clogs, abnormal fan/pump operation, or insufficient cooling medium flow/temperature.

Overfilling during maintenance: Excess initial oil volume expands significantly with temperature rises.

Solutions: If caused by cooling system faults, resolve the underlying issues. If due to overfilling, drain oil to the appropriate level. Confirm the oil level exceeds the maximum line before draining if visibility is lost.

2. Excessively Low Oil Level

A significantly low oil level (below the minimum line or invisible) relative to the current temperature indicates abnormal conditions. Causes include:

Oil leakage from the transformer.

Initially low oil level combined with sudden load reduction or ambient temperature drop.

Prolonged oil flow into coolers in forced oil-water cooled transformers.

Risks: Low oil levels trigger light gas relay alarms; float-type relays may even trip the heavy gas protection. Severe oil loss exposes core and windings to air, causing moisture absorption, insulation degradation, and potential breakdown.

Solutions: Replenish oil to normal levels immediately. For severe leakage, avoid switching gas protection from trip to signal mode; instead, stop leaks and restore oil levels. If leakage causes oil levels to drop below the gas relay or continue falling, shut down the transformer immediately.

3. False Oil Level

False readings may occur due to:

Non-bladder conservators: Blockages in the oil gauge tube, breather, or explosion-proof valve vents.

Bladder conservators: Trapped air, restricted bladder breathing, improper bladder installation, or bladder rupture.

Handling: First, disable the heavy gas protection before troubleshooting the root cause.

Guangxi Dingbo Power Equipment Manufacturing Co.,Ltd was founded in 1974 and is one of the earliest manufacturers of generators and diesel generator sets in China. The company has a registered capital of 218.88 million yuan. The company covers an area of 86,000 square meters and a building area of 55,000 square meters. There are more than 660 employees, including 456 professional technicians and 106 senior technicians. It has 46 sales and service outlets nationwide. The main products are diesel engines, generator sets, and diesel generators, providing users with a one-stop service of design, supply, debugging and maintenance at any time. Dingbo has always insisted on using first-class talents, building first-class enterprises, manufacturing first-class products, creating first-class services, and making every effort to build a first-class domestic enterprise. If any question please feel free to visit our website https://www.dieselgeneratortech.com/ or send email to [email protected].