ANSI 195 – Supervision Relay

The ANSI 195 Supervision Relay is designed to continuously monitor critical signals, power supplies, or trip circuits to ensure system readiness and reliable protection performance.

Where is the ANSI 195 Relay Used?

The 195 Supervision Relay is typically employed in:
✅ Line Panels → For monitoring breaker trip circuits.
✅ Busbar Panels → To supervise DC control supplies.
✅ Transformer Panels → For ensuring relay protection circuits are healthy.
✅ Control & Protection Panels → For monitoring critical protection relay connections.

Key Functions of the ANSI 195 Relay:

  1. Trip Circuit Supervision:
    • Monitors the health of the circuit breaker’s trip coil wiring, ensuring no open circuit, loose connection, or power loss is present.
    • If a problem is detected, the relay triggers an alarm to alert the operator.
  2. DC Supply Supervision:
    • Continuously monitors the DC control supply voltage to ensure breakers, relays, and alarms receive uninterrupted power.
  3. Relay Protection Supervision:
    • Ensures critical protection devices like 87L, 87B, or 21 Distance Relays are receiving proper signals and are not disconnected or faulty.
  4. Alarm and Indication:
    • Provides clear fault indications for faster troubleshooting.

Example Scenario 1: Trip Circuit Supervision in Line Panel

Suppose a 132kV transmission line uses a 195 relay to monitor the breaker trip circuit.

➡️ If the trip coil wiring gets damaged or disconnected, the 195 relay detects the fault and triggers an alarm before an actual fault occurs.
✅ This ensures operators can take preventive action before the breaker fails to trip during a real fault.

Example Scenario 2: DC Supply Monitoring in Busbar Panel

In a busbar panel, the 195 relay supervises the DC control supply.

➡️ If the DC voltage drops below a safe level (e.g., due to battery failure), the 195 relay alerts the operator to ensure prompt restoration.

Key Benefits:

  • Prevents breaker failure by ensuring trip circuits are healthy.
  • Improves system reliability by detecting wiring faults, loose connections, or DC power issues.
  • Provides early warning for potential faults, reducing downtime and improving maintenance response.

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