Basler Electric PRP210-1 – Reverse Power Relay for Generator Protection

The Basler Electric PRP210-1 (catalogue 9056300102) is a solid‑state directional power relay that monitors the real power flow in a synchronous generator. It trips when the generator absorbs power from the grid (motoring) instead of supplying it, preventing damage to the prime mover and ensuring safe operation of the unit.

Operating Principle

The relay measures the voltage and current of each phase and computes the active power. A directional element compares the phase angle between voltage and current; when the power vector reverses, the relay triggers after a user‑selectable time delay. The PRP210-1 offers both definite‑time and inverse‑time characteristics, allowing coordination with other protection devices. The pickup level is adjustable from 0.5% to 20% of the generator rated power.

• Power measurement range: 0–100% of nominal, accuracy ±2%

• Pickup setting: 0.5–20% (continuous adjustment)

• Time delay: 0.1–10 seconds (definite) or inverse curves

• Voltage input: 120 V AC, 50/60 Hz (sensing)

• Current input: 5 A from CT secondary

• Output contacts: 2 Form‑C relays, 5 A at 250 V AC

• Power supply: 120/240 V AC or 125/250 V DC (optional)

• LED indicators: power direction, alarm, and trip

• Operating temperature: –20 °C to +65 °C

Application Scenarios

The PRP210-1 is commonly installed in generator protection panels for steam, gas, and hydro turbines. It prevents motoring, which can cause turbine blade overheating and bearing damage. It is also used in industrial cogeneration plants where multiple generators share a common bus, ensuring that a failed unit is disconnected promptly.

Installation and Configuration

Mounting is via a standard panel cutout with front‑accessible controls. All settings are made using DIP switches and potentiometers, with a test jack for secondary injection. The relay can be configured for either single‑phase or three‑phase measurement, and includes a blocking input for external interlocking.

Reliability and Standards

Built with Basler’s proven analog/digital hybrid technology, the PRP210-1 offers high surge withstand and thermal stability. It meets ANSI/IEEE C37.90 and IEC 60255 requirements. Its compact design and robust construction make it a reliable choice for protecting critical generating assets.

In summary, the Basler Electric PRP210-1 reverse power relay provides accurate, adjustable protection against motoring, ensuring the longevity and safety of generators and their prime movers.