RMC-131D-Synchronization with Circuit Breaker Closing DEIF-RMC-131D-Zhangzhou Fengyun Electrical Equipment Co., Ltd.

Automatically outputs relay signals to drive the generator circuit breaker to close, achieving safe parallel operation. Built-in dynamic synchronization logic: forced positive slip grid connection (generator frequency slightly higher than bus frequency), eliminating reverse power impact at the source and protecting the unit. The circuit breaker has an inherent mechanical closing time Tms. The module calculates the slip speed in real time and outputs the closing pulse in advance to ensure that the phase difference of the circuit breaker contacts is close to 0° at the moment of closing, eliminating grid connection inrush current. It is widely used in parallel systems of ships, diesel power stations, and standby generator sets.

Description

　　Many products are not yet listed. Please contact us for more product information.

　　If the product model differs from the displayed image, the model number shall prevail. Please contact us for specific product images; we will arrange to take photos in our warehouse for confirmation.

　　We have 76 shared warehouses worldwide, so it may sometimes take several hours to accurately return the information to you. We apologize for any inconvenience. Of course, we will respond to your inquiries as soon as possible.

　　Other names for RMC-131D:

　　RMC-131D Synchronizer Controller

　　RMC-131D Frequency Monitor

　　The RMC-131D is a dedicated automatic synchronization and grid connection module (ANSI 25 synchronization device) from DEIF. Its core function is to collect generator + bus voltage, frequency, and phase data; automatically adjust speed and voltage; and output a closing pulse after all synchronization conditions are met to drive the generator circuit breaker for safe grid connection. It is widely used in marine power plants and industrial diesel/gas generator sets.

　　II. Core Control Logic for Synchronous Closing

　　Grid connection requires four conditions to be met simultaneously; none can be missing. Only when all conditions are met will the circuit breaker closing signal be output:

　　Voltage Difference ΔU Qualified: The voltage difference between the generator and the bus ≤ the threshold value set by the panel VOLTAGE knob (default 2%)

　　Frequency Difference Δf Qualified: The slip frequency ≤ the FREQ knob setting value (adjustable 0.05~0.5Hz), while monitoring the frequency change rate dƒ/dt to prevent frequency overspeed oscillation.

　　Phase Angle Difference Qualified: The phase difference is stable within ±5° and remains stable for 1 second.

　　Phase Sequence Verification Normal: The phase sequence of the generator and bus input phases is consistent; incorrect phase sequence directly blocks closing.

　　Advanced Closing Compensation (Circuit Breaker Mechanical Delay TBC)

　　The circuit breaker closing has an inherent mechanical action delay. The panel TN (TBC) knob specifically compensates for this closing delay:

　　TN Setting Value = Circuit Breaker Inherent Closing Time (unit: ...) ms, 0~500ms)

　　The module will send a closing pulse TN milliseconds in advance, ensuring the phase of the circuit breaker's main contacts closes just close to 0°, avoiding inrush current and reverse power faults.

　　III. Panel Knob Functions (Synchronization/Closing Parameter Setting)

　　The panel has 5 adjustable potentiometers, all corresponding to synchronous closing logic:

　　Tₙ(TN): Circuit breaker closing delay compensation, 0~500ms, matching switch opening and closing speed

　　Xₚ: Maximum allowable phase difference, factory ±5°, not recommended to increase, as this can easily cause grid connection impact

　　FREQ(Δf): Maximum allowable slip frequency 0.05~0.5Hz; generally 0.1Hz for diesel generator sets, 0.2Hz for gas generators. If the slip is too fast, no closing signal will be sent; includes df/dt frequency change rate protection, prohibiting closing when the frequency fluctuates drastically;

　　VOLTAGE(ΔU): Allowable voltage difference range 1%~12%, standard setting 2%~5%, generator-bus voltage difference exceeds limit, closing is blocked;

　　BREAKER(tₘₛ): Closing relay output pulse width, fixed 400ms standard closing pulse, duration cannot be changed. The circuit breaker has an inherent mechanical closing time Tms. The module calculates the slip velocity in real time and outputs the closing pulse in advance to ensure the phase difference of the circuit breaker contacts is close to 0° at the moment of contact closure, eliminating grid inrush current.

　　Status LED Indicators

　　POWER: Normal power supply, normally lit; 2~3Hz flashing = module self-test fault, synchronous closing all locked

　　UG/UB: Generator voltage and bus voltage acquisition normal

　　Δf: Frequency difference over-limit alarm

　　ΔU: Voltage difference over-limit alarm

　　SG▲/SG▼: Automatic speed control output (speed increase/deceleration)

　　SYNC: All synchronization conditions met, closing pulse output in progress

　　IV. Terminal Wiring (Synchronous Acquisition + Closing Output)

　　1. Voltage Acquisition Terminals (Synchronous Judgment Signal)

　　Bus Voltage: 24=L1, 26=L2

　　Generator Voltage: 29=L1, 31=L2

　　Only two-phase voltage sampling, must be connected in the same phase sequence, missing phase/reversed phase directly prohibits closing

　　2. Circuit Breaker Closing Output Terminals (Core Closing Circuit)

　　Terminals 8, 9, 10 are SYNC Synchronous Closing Relay Passive Contacts

　　8-9: Normally open contacts. Close upon reaching synchronization threshold, outputting a 400ms closing pulse, which is then fed into the circuit breaker closing coil circuit.

　　Capacity: For low-voltage control circuits; cannot directly drive high-power closing coils. An intermediate relay is required for capacity expansion.

　　Terminals 8/9/10 are SYNC closing passive relay contacts. Only when voltage, frequency difference, and predicted phase angle are all within acceptable limits will the contacts close, outputting a closing command to the circuit breaker closing circuit. The green SYNC LED on the panel will illuminate, indicating that the closing pulse is being output. If any synchronization condition exceeds the limit, the closing signal will be immediately cut off.

　　3. Speed Control Output

　　SG▲, SG▼ Passive Contacts: Automatically output acceleration/deceleration signals when the frequency difference is too large, adjusting the diesel engine actuator to reduce the frequency difference to the synchronization range.

　　V. Complete Automatic Synchronous Closing Process

　　Module power-on self-test: POWER green light remains constantly on; collects two-phase voltages of the bus and generator; phase sequence errors directly lock out.

　　Continuously compare ΔU, Δf, and phase angle:

　　Excessive frequency difference: SG▲/SG▼ alternate operation to adjust generator speed and reduce slip.

　　Voltage deviation: corrects generator terminal voltage in conjunction with AVR voltage regulation circuit.

　　When ΔU, Δf, and phase difference all enter the set threshold and remain stable for 1 second, the SYNC light illuminates.

　　Based on the circuit breaker delay set by TN, drives contacts 8-9 to close milliseconds before TN, outputting a 400ms closing pulse.

　　The circuit breaker receives the pulse and closes, completing grid connection; the synchronization pulse automatically disconnects after closing.

　　If any parameter exceeds the limit (voltage, frequency, phase deviation), immediately cuts off the closing output and locks out grid connection.

　　VI. Typical Faults (Troubleshooting for Unable to Output Closing Pulse)

　　POWER Flashing light: Module hardware failure, synchronization function completely ineffective.

　　ΔU constantly on: Generator/bus voltage deviation too large, PT disconnection, loose wiring.

　　Δf constantly on: Unstable speed, speed controller actuator failure, slippage continuously exceeding limits.

　　SYNC light never on: Phase cannot be stabilized within ±5°, phase sequence reversed, TN parameter setting too high/too low.

　　SYNC on but circuit breaker does not close: Closing circuit disconnection, 8-9 contact damage, closing coil failure, insufficient pulse width.

　　VII. Application Differentiation and Advantages

　　Compared to HAS-111DG (semi-automatic synchronizing meter), RMC-131D is a fully automatic synchronous closing device: no manual operation required, automatic speed and voltage regulation + automatic closing pulse generation, built-in circuit breaker delay compensation, significantly reducing grid connection impact, suitable for multi-unit parallel power stations and ship main switchboards.

Previous: RSQ-3-Synchronization with Circuit Breaker Closing DEIF-RSQ-3 Next:DCP2-1205-Synchronization with Circuit Breaker Closing DEIF-DCP2-1205 Return to List