Beckwith Electric M‑0245B High Speed Sync‑Check Relay
The Beckwith Electric M‑0245B is a high‑speed sync‑check relay designed to verify synchronism conditions before closing a circuit breaker or automatic transfer switch. It provides fast and accurate voltage magnitude, phase angle, and frequency matching between two independent sources, enabling safe paralleling of generators or transfer between utility and emergency power.
This relay is built with solid‑state technology, offering response times of less than 100 ms. It features adjustable voltage, frequency, and phase angle windows, as well as a built‑in timer for dead‑bus closure. The M‑0245B is compact and suitable for panel mounting.
Key Features
Voltage match: 80–120% of nominal (adjustable)
Phase angle window: ±5° to ±20° (adjustable)
Frequency difference: 0.1–2.0 Hz (adjustable)
High‑speed operation: < 100 ms
Dead‑bus and live‑bus closure capability
Output relay with form‑C contacts
LED status indicators
Technical Specifications
Input: 120/240 VAC, 50/60 Hz; burden: < 5 VA; accuracy: ±1% for voltage, ±0.02 Hz for frequency; output contacts: 1 x SPDT, 5 A; operating temperature: -20°C to +65°C.
Applications
Used in generator paralleling switchgear, automatic transfer switches, and breaker control schemes. It ensures that two AC sources are in synchronism before closing, preventing equipment damage from out‑of‑phase switching.
Installation and Setting
Mount the relay on a panel. Connect the voltage sensing leads from both sources. Adjust the voltage, phase angle, and frequency windows using the front‑panel potentiometers. The relay includes a test switch for commissioning.
Reliability and Maintenance
The solid‑state design provides long life with no moving parts. The relay is protected against transients and surges. Periodic verification of settings is recommended.
Why Choose the M‑0245B?
This relay offers a cost‑effective, high‑speed solution for synchronism verification, backed by Beckwith Electric’s expertise. Its compact size and easy adjustment make it ideal for retrofit and OEM applications.
In summary, the Beckwith Electric M‑0245B ensures safe and reliable switching between AC sources, enhancing system integrity.
