ABB T-1521Z protective relay

ABB T-1521Z

The ABB T-1521Z is a protective relay from ABB’s T1 series, designed for overcurrent and earth-fault protection in medium-voltage (MV) and high-voltage (HV) systems. Below are its typical technical parameters:

General Specifications:

• Supply Voltage:
  • 48–250 V AC/DC (depending on model)
• Frequency: 50/60 Hz

Protection Functions:

1. Overcurrent Protection (50/51):

• Current Setting Range: 0.1–30 A (adjustable)
• Time Delay (DT/IDMT):
  • Definite Time (DT): Adjustable (e.g., 0.05–300 s)
  • Inverse Time (IDMT): Standard curves (IEC, IEEE, etc.)

2. Earth-Fault Protection (50N/51N):

• Current Setting Range: 0.02–5 A (adjustable)
• Time Delay: Similar to overcurrent (DT/IDMT)

3. Optional Functions:

• Directional Overcurrent (67/67N) (if supported)
• Thermal Overload (49)

Current Inputs:

• Rated Current (Iₙ): 1 A or 5 A (configurable)
• Burden: < 0.1 VA per phase

Binary Inputs/Outputs:

• Binary Inputs: 4–8 (for control signals, e.g., trip, reset)
• Relay Outputs: 4–6 (NO/NC contacts for tripping, alarms)

Communication & Interfaces:

• Optional Protocols:
  • Modbus RTU (RS485)
  • IEC 60870-5-103 (some models)
• Front-Panel Display: LCD/HMI for settings & status

Mechanical & Environmental:

• Operating Temperature: -25°C to +55°C
• Humidity: Up to 95% RH (non-condensing)
• Enclosure: IP20–IP54 (depending on model)

Standards & Certifications:

• Compliance: IEC 60255, IEEE C37.90
• EMC: IEC 61000-4 (surge, EFT, RF immunity)

Typical Applications:

• Motor protection
• Feeder & transformer protection
• Industrial & utility power systems