What are the disadvantages of reclosers?

Answered by James Porterfield

As an expert in the field, I have encountered several disadvantages of reclosers that should be carefully considered before incorporating them into power distribution systems. These drawbacks can have a significant impact on the overall efficiency and reliability of the system.

1. Increased stress and wear on equipment: Reclosers operate by closing and opening circuit breakers in response to faults in the system. This repetitive action can lead to increased stress and wear on the power system equipment, including circuit breakers, transformers, and other components. Over time, this can result in higher maintenance and replacement costs.

2. Impact on conductors: The repeated fault currents and voltage fluctuations caused by reclosers can have a detrimental effect on the conductors in the power distribution system. These fluctuations can lead to increased heating and stress on the conductors, potentially reducing their lifespan and increasing the risk of failures or outages.

3. Voltage flicker and fluctuations: Reclosers can cause voltage flicker and fluctuations during their operation. This can have a negative impact on sensitive electronic equipment connected to the power distribution system, such as computers, telecommunication devices, and sensitive industrial machinery. Voltage fluctuations can lead to malfunctions or damage to these devices, resulting in costly repairs or replacements.

4. Impact on power quality: Reclosers can also affect the overall power quality in the distribution system. The repeated opening and closing of circuit breakers can introduce harmonic distortion and other power quality issues. This can lead to interference with other electrical devices connected to the system and affect the performance of sensitive equipment.

5. Increased fault clearing time: While reclosers are designed to automatically restore power after a temporary fault, there can be instances where the fault persists or reoccurs. In such cases, the recloser may go through multiple attempts to restore power before finally tripping and isolating the fault. This delay in fault clearing time can result in prolonged outages and inconvenience to customers.

6. Limited fault isolation capability: Reclosers are primarily designed to detect and clear temporary faults. However, they may not be as effective in identifying and isolating permanent faults or faults located further down the distribution system. This can lead to extended outages and difficulties in locating and repairing faults.

7. Safety concerns: Reclosers can present safety concerns, particularly during maintenance or repair activities. Since they are designed to automatically restore power, there is a risk of unexpected re-energization during work, potentially endangering the safety of maintenance personnel.

While reclosers offer benefits in terms of rapid fault detection and restoration of power, they also come with several disadvantages that need to be carefully considered. These include increased stress and wear on equipment, impact on conductors, voltage flicker and fluctuations, impact on power quality, increased fault clearing time, limited fault isolation capability, and safety concerns. It is important to weigh these drawbacks against the advantages of reclosers to determine their suitability for specific power distribution systems.