Hager SBR399 Modular Switch Disconnector Isolator 125A 3 Pole 400V 3 Module Red Toggle DIN Rail

Description

The 125A three-phase isolator.

The Hager SBR399 is a 125A three-pole modular switch disconnector (isolator) with a red toggle, the top of the three-phase range, giving safe, visible manual isolation of a 400V circuit from a 3-module DIN rail body.

Key Features

• Rated current: 125A, three-phase (3P)
• Red toggle switch disconnector; 3NO poles
• Utilisation category AC22A (and AC21A) at 125A
• Rated voltage 400V AC, insulation voltage 440V
• 3-module width (52.5mm) DIN rail mount
• High-capacity terminals: rigid 6–50mm², flexible 6–35mm²
• Rated impulse withstand voltage 6000V; IP20; IEC 60947-3
• Icm 2.11kA making, Icw 1.5kA short-time withstand

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Why it Matters

Isolate the whole three-phase supply.
The SBR399 sits at the top of Hager's three-phase modular isolator range, disconnecting all three phases of a 400V circuit at up to 125A on a single red toggle. It is a switch disconnector, not a circuit breaker – built for positive manual isolation for maintenance and safe working rather than automatic tripping. Rated for AC22A duty to IEC 60947-3, it makes and breaks mixed resistive and inductive loads, backed by a strong 2.11kA making capacity and 1.5kA short-time withstand for heavy main-switch duty.

Main-switch cabling in three modules.
The SBR399 spans three DIN modules (52.5mm wide, 83mm high, 68mm deep) on standard 35mm rail. Its high-capacity terminals accept rigid conductors from 6 up to 50mm² and flexible from 6 up to 35mm² per pole at a 3.6Nm tightening torque, sized for the sub-main cabling a 125A three-phase feed runs, and it is rated for 40,000 mechanical operations for dependable long-term service.

Built for Australian switchboards.
With a 6kV rated impulse withstand voltage and IP20 protection, the SBR399 operates from -20°C to 70°C, covering meter boxes, plant rooms and commercial and industrial distribution boards across Australian conditions on standard 35mm DIN rail. With 24W dissipation at full load, plan board ventilation and spacing accordingly. Optional Hager accessories include the MZN175 padlockable locking kit, MZN121 inter-pole barriers, MZN120 terminal shield, KRN199 neutral connecting block and the ESC080 auxiliary contact.

Q: Is the Hager SBR399 a circuit breaker?
No. It is a three-pole switch disconnector (isolator) for safe manual isolation of a three-phase circuit; it does not provide automatic overload or short-circuit tripping like an MCCB.

Q: What voltage and load is the SBR399 rated for?
400V AC three-phase at 125A under the AC21A/AC22A utilisation categories, covering resistive and mixed inductive loads.

Q: What cable can the SBR399 terminals take?
Rigid conductors from 6 to 50mm² and flexible from 6 to 35mm² per pole, tightened to 3.6Nm – sized for a 125A three-phase sub-main.