ABB's VMAX vacuum circuit breaker shares much of its underlying platform with the VD4 — the same tulip contact family, the same EL2-mechanism coil and relay parts — but it has its own distinct truck, mechanism, and insulation components that don't cross over. If you're sourcing spares for a VMAX breaker, here's exactly what to check for, model by model.
Contact System
Like the VD4, VMAX uses tulip contact assemblies rated from 630A to 3150A+ in 8, 10, and 12-finger configurations — these are shared part numbers across the VD4/VMAX family, so a VD4 tulip contact will fit a VMAX pole of the same rating. Where VMAX diverges is the contact arm assembly (1VCR005944G0001, rated 1250A, aluminium construction) — this is VMAX-specific and won't interchange with VD4's contact arm parts.
Truck & Mechanism
VMAX's common truck assemblies are sized the same way as VD4's (12.12.25, 12.12.40, 12.25.40, 12.31.40 and the 40°/50° ambient variants), but are separate part numbers from the VD4 truck family — always confirm against the breaker's frame size and mechanism generation before ordering. For older EL2-mechanism units, the ENBLOC assembly (1VCR002320G0001) is the complete drop-in mechanism-and-contact unit; the OPER. MECH EL2 (510507-810) is the standalone operating mechanism if only that needs replacement.
Insulation & Enclosure
VMAX has its own insulating cover parts — a central cover (1VCR007464F0001) and a side cover (1VCR007465F0001) — sized specifically to the VMAX enclosure profile, distinct from VD4's covers.
Coils & Relays (shared with VD4)
The full coil and relay lineup is common across VD4/VMAX/VBF-EL3 since they share the same EL/MO/MC mechanism platform:
- Opening coils (MO/MO1) — 24V, 30V, 48V, 110–132V, and 220–250V AC/DC variants
- Closing coils (MC) — same voltage range as opening coils
- Undervoltage coils (MU) — 24V, 48V, 110–132V, and 220–250V variants
- Additional-trip coils (MO2) — 24V, 48V, 110–132V, and 220–250V variants
- APPL-RL1 auxiliary relay — 110V and 220–240V AC/DC, used with the mechanism's control circuit
- Geared charging motors — 48–60V, 100–130V, and 220–250V AC/DC
Auxiliary Switches & Mechanical Spares
VMAX shares its auxiliary switch part numbers with VD4 (2O+3C and 3O+2C silvered contact configurations, plus a 5-contact BT1/BT2 variant). Other commonly stocked mechanical spares: the shock absorber assembly, the cable stem/64-pin plug assembly (VMAX-specific part number, not interchangeable with VD4's), the micro switch assembly for the closing spring, and the closing spring micro switch itself.
Ordering the Right Spare
Because VMAX and VD4 share so many coil/relay/contact part numbers but have distinct truck, mechanism, and cover parts, always confirm the exact breaker model from the nameplate before ordering — don't assume a VD4 part number is safe just because the breaker "looks the same." For coils and motors, the control voltage stamped on the mechanism or nameplate determines the correct variant.
TEKTOW stocks spares for both VD4 and VMAX platforms. See our VD4 spares guide for that platform's specifics, or the full ABB switchgear spares guide covering all our stocked breaker, RMU, and panel families. You can also download the part-number catalogue or send us your nameplate details for a quote.