Eaton PKZM0-0.4-T Transformer Protection Circuit Breaker, 3-Pole, 0.25-0.4 A, Thermal-Magnetic, Rotary Handle 088909

In industrial control panels and machine tool electrical cabinets, the Eaton PKZM0-0.4-T safeguards small transformers from overloads and short circuits. This 3-pole motor-protective circuit breaker is manually operated via a rotary handle and features a thermal-magnetic trip unit with a fixed instantaneous release at 6.2 A. Its adjustable thermal overload range (0.25–0.4 A) allows precise matching to transformer primary currents, ensuring reliable protection without nuisance tripping.

Key specifications

• Number of poles: 3
• Rated operational current (Ie): 0.4 A
• Thermal overload release setting range: 0.25 – 0.4 A
• Instantaneous short-circuit release: 6.2 A (fixed)
• Rated operational voltage (Ue): up to 690 V AC
• Rated insulation voltage (Ui): 690 V
• Rated impulse withstand voltage (Uimp): 6 kV
• Short-circuit breaking capacity (Icu) at 400 V: 80 kA
• Actuation type: Rotary handle (manual)
• Mounting type: DIN rail / screw mounting
• Degree of protection (front): IP20
• Ambient operating temperature: -25 to +55 °C
• Release characteristic: Thermal-magnetic (for transformer protection)
• Connection type: Screw terminals
• Terminal capacity (solid/stranded): 1 x (1–6 mm²) / 2 x (1–2.5 mm²)
• Standards: IEC/EN 60947-2, IEC/EN 60947-4-1
• Mechanical life: 100,000 operations

Why choose it

The PKZM0-0.4-T is engineered for reliable transformer protection in industrial environments. Its precise thermal adjustment and high breaking capacity ensure dependable operation, while the compact design saves space in control panels. The rotary handle provides clear ON/OFF indication and allows manual isolation, enhancing safety during maintenance. With screw terminals and DIN rail mounting, installation is straightforward and secure.

Ideal use cases

• Protection of control transformers in machine tools and production lines
• Primary-side protection of small transformers in HVAC and pumping systems
• Motor and transformer protection in conveyor and packaging machinery
• Use in control cabinets requiring manual reset and high short-circuit ratings

Good to know

The PKZM0 series is widely used in industrial automation and complies with international standards. The breaker is suitable for three-phase systems up to 690 V and can be mounted on standard 35 mm DIN rails or screwed directly to a panel. Its IP20 front protection is intended for installation in enclosed electrical enclosures. For auxiliary contacts or shunt trips, compatible accessories are available separately.