Electrical Sub Station : Indoor v/s Outdoor Substations

In Basics of Electric Sub Station, we discussed basics of Electric sub station and need of electric sub station and different types of electric sub stations. In current article we'll discuss the differences between Indoor and Outdoor sub stations.

Differences Between Indoor and Outdoor Sub Station

• Capital Cost : The Capital required to install indoor substation is very high because a lot of buildings are to be manufactured in case of Indoor substation while the capital required for outdoor sub station is small as compare to Indoor sub station.
• Civil Work : In case of Indoor substation, first we have to prepare building to host larger electrical equipment like Transformers and have to make cut outs for power cables that are bringing power to the sub station. these requires a lot of civil work and hence increasing time required to install the sub station in opposition to this only a small construction work is required in outdoor sub stations.
• Fault Location : Indoor substations are very compact in arrangement and hence if there is any fault then the location of fault become very difficult while in outdoor sub stations the equipment are placed at different locations so the fault can be sensed easily.
• Future Expansion : In Indoor sub stations the buildings are constructed according to the size of present transformer so if in future we want to increase the rating of sub station then we have to demolish or make some civil works in the building to host new transformer while in outdoor substations transformers are placed outside so they may be replaced by just increasing the area of fencing.
• Safety : Indoor substations are more safe as they restrict the entry of animals or any unauthorised person near the transformer while outdoor substations are not much safe.
• Appearance : Indoor sub stations looks good because there is not and electrical equipment that is visible from outside while in outdoor sub stations appearance is not very good.
• Maintenance : Maintenance of Indoor substation is not easy. It require both time and specialised labour so it is costly while maintenance of outdoor substation is cheap.