What do you mean by emergency supply? The DC station supply (which operates under both normal and emergency conditions), or a standby generator used for emergency situations only?
If it is DC supply, relays emergency lighting inside the sub stations, breakers for tripping and closing etc. may be connected. If an emergency AC backup is provided then some critical equipments of the plant may also be supplied as per the requirment of the process.
We can also add the following to the mentioned above items:
1. Fire and Jockey Pumps.
2. Water Pumps.
3. Sewage Pumps.
4. Means of egress Lighting.
5. Computer Rooms Air Conditioning.
6. IT Server.
7. Selective number of socket outlets (According to application and function)
8. Portion of the lighting of the whole building.
9. Essential loads (EX. operational room equipment in hospitals and the same)
10. Security Systems.
11. Ticketing counters, loading bridges, conveying Systems etc. in airports.
And there may be other loads according to the type of application and the point of view of the designer and/ or client requirements.
Elecme