HMG Power Systems Pvt. Ltd. Offers In Tank Oil type OLTC - On Load Tap Changer. HMG Power Systems Pvt. Ltd. Manufactures HV circuit breaker and its auxiliary equipment, electrical and mechanical components and accessories, On Load Tap Changer [OLTC], High Voltage Disconnector, and Compact Switch gear etc. The In Tank Oil type OLTC - On Load Tap Changer is used for Oil immersed distribution transformers. The In Tank Oil type OLTC - On Load Tap Changer has different connections like Y for neutral point of star contention, D for any selectable winding position, Single phase apply to extinction coil.