LHB (Linke Hoffmann Bosch) coaches — now manufactured by all Indian Railways production units — draw their 'hotel load' (AC, lighting, fans, pantry equipment) from one of two systems: End-On-Generation (EOG) or Head-On-Generation (HOG). Both differ fundamentally from the self-generating (SG) system covered earlier in this subject.
End-On-Generation (EOG)
Power cars sit at both the front and rear of the rake, each feeding coaches in between. Each power car carries two DG sets (one standby). Power is distributed via two feeders running the full length of the rake at 750V, 3-phase, 4-wire, 50Hz AC — every coach carries its own 60 kVA step-down transformer to bring this down to 415V, 3-phase, 4-wire, 50Hz for actual use.
The two power cars at each end take the ENTIRE load of the whole rake — air conditioning, light/fan circuits, emergency battery charger circuit, and pantry equipment all draw from this same feeder pair.
Head-On-Generation (HOG)
In HOG, the electric locomotive itself supplies the hotel load — no separate power car is needed at all. Power flows: OHE → pantograph → locomotive's traction transformer, which carries a dedicated hotel-load winding rated 2 × 622.5 kVA at a nominal 960V single-phase (this voltage varies with OHE fluctuations). This 960V feeds the Hotel Load Converter (2 × 500 kVA, i.e. two 500kVA units per locomotive), which outputs 750V 3-phase 50Hz — then transmitted to both feeders of the existing EOG-style train wiring via the inter-vehicular (IV) coupler.
Coach Classification
LHB variant coaches based on EOG/HOG broadly split into: LHB AC Coach, LHB Non-AC Coach, Power Car, and Pantry Car. Within LHB AC coaches specifically, the further split is AC Sleeper Coaches and AC Chair Cars — each with its own coded designation (e.g. First AC, Executive, Second-class sleeper codes, tracked by a standardised code system across Indian Railways).