Beckwith M-0388/M-0389 synchronous verification relay

Beckwith M-0388/M-0389 synchronous verification relay

Overall positioning of the product

1. Product composition

The entire device is composed of M-0388 phase synchronization verification main relay and optional matching M-0389 voltage verification unit, belonging to the Syncrocloser synchronization product line, providing synchronization locking criteria for power circuit breaker closing.

2. Core purpose

As a backup interlock for the M-0193 automatic synchronization device, it provides dual protection to prevent large angle grid impact;

Synchronous monitoring of manual closing of power grid interconnection switches and generator outlet circuit breakers;

Parallel verification of islanded power grid during system fault recovery;

Can directly replace GE IJS/SLJ and Westinghouse CVE old-fashioned electromechanical synchronous relays.

M-0388 Phase Verification Unit Core Parameters and Functions

（1） Voltage input specifications

Line and Bus PT input rated at 120Vac; Long term withstand voltage of 150Vac, 1-second short-term withstand voltage of 200Vac; Load: 4VA on the high voltage side, 1VA on the low voltage side; at least one input device with a voltage greater than 100Vac is required to operate.

（2） The front panel can be adjusted

Phase Limit Window

On board code switching range: X1 (0~± 45 °)/X2 (0~± 90 °), the corresponding X2 indicator light on the panel lights up, and the scale accuracy is ± 5% of the full range; The phase exceeds the window timer and is immediately reset.

Time Limit Delay Window

On board code switching: X1 (0~1.5s)/X10 (0~15s), X10 indicator light on, accuracy ± 10%; Only when the phase continuously falls within the set window and the timer is completed, the closing output will conduct.

Operational/Test Switch

The TEST gear isolates the external PT input and locks the closing output. The device can be verified separately through the panel test socket without affecting the primary circuit.

（3） Output and remote signaling circuit

Closing main output (standard type 2 sets of Form A normally open)

Single short-term connection 10A, 125Vdc inductive disconnect 0.9A, 250Vdc disconnect 0.4A; two parallel connections can reach 20A; ground withstand voltage 1500Vac/1min.

Dedicated output for voltage loss (dead wire/dead bus optional)

1 normally open closing contact+1 normally closed light load contact: any contact of the line/bus with a voltage greater than 80V is disconnected, and both contacts with a voltage less than 50V are closed, with a capacity of 3A@240Vac .

State remote signaling contact (Form C conversion)

Phase qualified remote signaling of PHARE STATION, used for SCADA local indicator lights, 3A resistive @ 120Vac.

Analog transmission output (compatible with SCADA)

Phase 0~180 ° dual mode:

Voltage type: 0~10Vdc, accuracy ± 1 °, load ≥ 5k Ω;

Current type: 0~1mA DC, accuracy ± 3 °, load ≤ 10k Ω;

No electrical isolation, shared common negative pole.

（4） Logical optional configuration (synchronous enable terminal TB2)

Two types of internal timer logic:

Enable the contact to only control the output, and the phase standard timer will time normally;

When the enable contact is disconnected, the timer continuously resets and only starts counting after it is closed.

Optional M-0389 voltage verification unit function

It must be installed in conjunction with M-0388, with superimposed voltage upper and lower limits and voltage loss closing criteria. If all voltage conditions are not met, it can be directly locked and synchronously closed.

1. Panel setting knob

UPPER VOLTAGE LIMITED Voltage Upper Limit: 110~140Vac, Accuracy ± 5%; The voltage of both the wire and bus must not exceed this value;

Lower voltage limit of LOWER VOLTAGE LIMIT: 90~120Vac, accuracy ± 5%; Both wires and busbars must be higher than this value;

DEAD LINE/BUS LIMIT voltage loss threshold: 0~60Vac, accuracy ± 10%; If the voltage of the line/bus is lower than this value, ignoring the phase, it is allowed to close directly (fault system recovery, no-load bus closing scenario).

2. Action response timing

Normal synchronization (under voltage): When both voltage and phase conditions are met, the output will conduct in approximately 0.2 seconds;

Dead line/dead bus closing: If the voltage is below the threshold, output immediately within 0.5 seconds without verifying the phase.

3. Voltage remote signaling and analog transmission

Remote signaling contact for voltage qualification status;

Wire/bus simulation transmission: 0~150V corresponds to 0~7.5Vdc/0~1mA dc, with a full temperature accuracy of ± 5%;

4. Voltage interlock logic options

Mode 1: If the voltage exceeds the limit, the phase timer will not be reset and only the final closing output will be locked;

Mode 2: If any voltage exceeds the upper and lower limits, the phase timer will be reset directly.

Hardware and testing matching

1. Modular design

The phase board and voltage board can be plugged and unplugged with power on, without the need for power-off maintenance of the entire machine; Equipped with M-0292 testing cable, maintain electrical connection after unplugging, and perform offline verification in the laboratory/on-site.

2. Immunity and environmental indicators

Transient protection: meets the ANSI/IEEE C37.90.1 oscillation surge standard;

RF anti-interference: 20V/m multi band RF without misoperation;

Working temperature: -40 ℃~+85 ℃ (analog output upper limit+60 ℃);

Humidity: 85% without condensation; PCB anti mold coating;

No need for factory/on-site calibration, all solid state precision components, no temperature compensation circuit drift.

3. Physical installation

Half embedded panel installation, compatible with GE S1 and Westinghouse FT-21 plug-in relay cabinets;

The whole machine contains M0389 with a net weight of 4.1kg and is transported at 5.4kg. It is equipped with a transparent protective cover to prevent accidental adjustment of the knob;

All terminals are gold-plated dry contacts, and gold-plated contacts must be used for external enable/lock circuits to reduce contact failures.

Typical application wiring scheme

Option 1: Cooperate with M-0193 automatic synchronization device (grid connected power plant generator)

The closing output of M-0193 is connected in series with the output of M-0388 to form a dual phase lock; M0388 provides static phase window backup protection, while M0193 is responsible for dynamic slip zero phase prediction, significantly reducing the risk of grid impact.

Option 2: Grid interconnection switch/system restoration

M-0388 is used independently and enables the Dead Line/Dead Bus voltage loss closing function; SCADA reads phase and voltage analog signals, and schedules remote judgment of closing safety conditions.

Maintenance, Safety, and Standardization

Maintenance requirements: It contains MOS sensitive chips inside and releases human static electricity before opening the cover; Prohibit live plugging and unplugging of backplane terminals, measuring circuit board resistance, as it may cause permanent damage to components;

On site testing process: Turn the dual TEST switch to the bottom, isolate the external PT, input 120V test voltage into the dedicated socket on the front panel, and the TEST C light is on to indicate normal logic;

Fault repair: There is no on-site adjustable calibration point, and the fault requires the entire machine to be returned to the factory for repair; Only damaged fuses are not covered by the warranty;

Safety warning: The terminal contains lethal high voltage. Only licensed electrical personnel should operate it after power off and discharge. It is prohibited to use it in flammable and explosive environments.