1. Prolonged Overload Operation
One of the most common causes of DP current transformer overheating is overload operation time. When the actual operating current exceeds the transformer's rated current, the load on the inner winding and core increases significantly, generating a substantial amount of heat.
Prolonged overload can lead to:
- Rising winding temperatures
- Aging insulation
- Decreased measurement accuracy
- Shortened service life
In severe cases, it can even burn down transformers.
2.Abnormal Overheating caused by secondary circuit opening
During operation, the secondary circuit of the current transformer cannot be opened, which is an important safety requirement in industry.
When the DP Current Transformer secondary circuit is accidentally opened, it causes:
- a sharp increase in secondary voltage
- Severe core saturation
- Abnormal increase in internal magnetic flux
In this situation, the transformer can quickly overheat, potentially damaging the insulation system and even endangering human safety.
Therefore, it is necessary to ensure reliable secondary circuit connections during operation.
3. Poor terminal contact
Loose, oxidized or poorly touched terminals of DP current transformers are also prone to local overheating.
When the current flows through the contact resistance, the increase in the contact resistance results in the generation of heat.
Common causes include:
- Loosen wiring screws
- metal terminals oxidation
- Improper installation
- Long-term vibration leads to unstable contact
This heat production is usually concentrated at the wiring points and can lead to further combustion if not addressed in a timely manner.
4. Increase in core losses
During operation, the core of DP Current Transformer produces magnetic loss. If the performance of the core material declines or ages over time, it can also lead to an increase in heat.
For example:
- Core ageing
- Abnormal magnetic flux density
- Material quality issues
All of this increases the loss of iron, leading to abnormally high overall temperatures.
This phenomenon is especially evident in high-frequency or high-load conditions.
5. Fever caused by insulating aging
After a long period of operation, the insulation material of transformer will gradually age.
When insulation performance deteriorates, the following may occur:
- Increased leakage current
- Partial discharge
- Increased dielectric loss
These problems can lead to the development of internal heat.
Especially in the environment of high temperature and humidity, the aging of insulation is usually faster, so it is necessary to carry out regular inspection of insulation condition.
6. High Ambient Temperature
The DP Current Transformer can also reduce their heat dissipation capacity of the transformer if the ambient temperature is too high during operation.
For example:
Summer heat, poor ventilation, limited installation space, distribution cabinet internal heat buildup.
All of this can significantly increase transformer temperature.
If heat dissipation conditions are not good, even under normal operating current, it is possible to overheat.