1. Basic Information

ABB PKZM0-16-T (originally Moeller series) is a 1-pole thermal-magnetic circuit breaker specially designed for transformer and small motor protection. As a dedicated MPCB (Motor Protection Circuit Breaker) with T-type characteristic, it effectively resists transformer inrush current and provides reliable overload and short-circuit protection for control transformers and auxiliary industrial loads. Featuring compact DIN-rail mounting and adjustable current setting, it is widely used in control cabinets, MCC systems and automated equipment power distribution circuits.

2. Technical Specifications

2.1 Basic Parameters

• Model: PKZM0-16-T
• Brand: ABB (ex Moeller/Eaton)
• Type: 1P Thermal-magnetic Transformer/Motor Protection Circuit Breaker
• Adjustable Current Range: 10～16A
• Characteristic: T-type transformer anti-inrush trip curve
• Mounting: Standard 35mm DIN rail
• Operation: Rotary current setting + manual handle switching

2.2 Protection Characteristics

• Thermal Overload Trip: Bimetallic strip, Class 10 inverse time characteristic, 10～16A adjustable
• Magnetic Short-circuit Trip: Instant electromagnetic trip, 8.5～14×Ir fixed threshold
• T-type Special Feature: Optimized delay logic to avoid false tripping caused by transformer switching inrush current

2.3 Electrical Ratings

• Rated Operating Voltage Ue: 690V AC
• Rated Insulation Voltage Ui: 690V AC
• Impulse Withstand Voltage Uimp: 6000V
• Short-circuit Breaking Capacity: 10kA
• Frequency: 50/60Hz
• Terminal Type: Screw terminal for copper cable

2.4 Environmental & Mechanical Data

• Operating Temperature: -25℃～+60℃
• Storage Temperature: -40℃～+85℃
• Humidity: 5%～95%RH (Non-condensing)
• Protection Class: IP20
• Mechanical Endurance: ≥100,000 cycles
• Electrical Endurance: ≥10,000 rated-load cycles

3. Main Features

• Exclusive Transformer T-curve: Optimized anti-inrush performance prevents false tripping during transformer power-on, ensuring stable startup while retaining precise overload and short-circuit protection.
• Dual Thermal-magnetic Protection: Integrates inverse-time overload protection and instantaneous short-circuit protection to comprehensively safeguard transformers, cables and terminal loads.
• Precision Adjustable Current: 10～16A continuous rotary adjustment matches different transformer ratings and auxiliary load requirements.
• High Industrial Ratings: 690V high voltage tolerance and 10kA breaking capacity adapt to complex industrial power distribution environments.
• Space-saving Compact Design: Narrow 1P structure minimizes cabinet space occupation with fast DIN-rail installation.
• High Operational Stability: Wide temperature resistance, vibration and EMC interference resistance support long-term 7×24h continuous operation.
• Visual Status Indication: Clear manual handle position displays on/off/trip status for easy on-site inspection and maintenance.

4. Working Principle

1. Normal Operation: The breaker remains closed, and loads operate steadily within the rated current range.
2. Inrush Current Resistance: The optimized T-type delay logic tolerates instantaneous transformer switching surge current without false tripping.
3. Overload Protection: Sustained overcurrent heats the bimetallic strip, triggers mechanical latch release and trips the breaker to prevent overheating damage.
4. Short-circuit Protection: Extreme fault current instantly energizes the magnetic coil for millisecond-level rapid tripping to isolate short-circuit faults.
5. Fault Reset: After fault elimination, manually reset the handle to restore power supply.

5. Typical Applications

5.1 Control Transformer Secondary Protection

5.2 Small Single-phase Motor Protection

5.3 Auxiliary Power Distribution Circuits

5.4 Old Equipment Maintenance & Replacement