Typical Protection/Accessories of a Transformer On-Load Tap Charger (OLTC)
On-load tap changer (OLTC) tank [5] of a main transformer is embedded to the transformer tank. The usual accessories and protection relays for OLTC includes;
1. Motorized tap changer (of course)
2. Pressure Relief Device (PRD) Relay
3. Buchholz Relay
4. Sudden (or Ramp) Pressure Rise Relay
These relays are separate from the main transformer protection relays. Also, OLTC has its own oil conservator.
Control box and mechanism for motorized, on-load tap changing.
Posted in Transformers and Accessories