DS200CVMAG3A | GE Speedtronic Vibration | In Stock

Description

Product Introduction

The GE DS200CVMAG3A is a legacy vibration monitoring module for the Mark V Speedtronic turbine control system. It is an enhanced version of the CVMAG3 with higher input over-voltage protection and improved input filtering. This board is for replacement in existing installations where field wiring may carry transient voltages.

Core advantage: The G3A revision adds ±30 V continuous input protection and TVS diodes on each channel. Standard CVMAG3 is damaged by 24 V DC applied accidentally (common in control panels where 24 V loops run near vibration cables). The G3A survives 24 V DC indefinitely and 120 V AC transients (1 ms). Field data shows G3A boards have 80% lower field failure rate than CVMAG3 in panels with mixed voltage wiring.

Key Technical Specifications

Key Selling Points & Differentiators

• Survives 24 V DC mis-wiring – Standard CVMAG3 input op-amps fail at 15 V. G3A withstands 30 V continuous. Technicians often accidentally connect 24 V loops to vibration inputs. G3A survives.
• TVS diodes for transient protection – Clamps 120 V AC to ±30 V. Protects against inductive kick from contactors, solenoids, and VFDs.
• Additional 1 kHz filter option – Software-selectable 1 kHz low-pass filter for high-frequency noise (e.g., VFD carrier frequencies). Standard CVMAG3 has 4.5 kHz only.
• Same pinout as CVMAG3 – Drop-in replacement. No wiring changes.
• Compatible with all Mark V firmware – Works with R1 through R4 racks, firmware v3.x through v7.x.
• Live tested with 24 V DC over-voltage – We apply 24 V DC to each input for 1 hour. Board must recover and read correctly when ±10 V signal reapplied.
• 30-day warranty with cross-ship – Input protection failure or channel drift? We send replacement same day.

Frequently Asked Questions (FAQ)

Q: What is the difference between DS200CVMAG3 and DS200CVMAG3A?
A: Input protection. CVMAG3: ±15 V max, no TVS diodes, fails at 24 V. CVMAG3A: ±30 V continuous, TVS diodes for transients, survives 24 V mis-wiring. The G3A draws 10 mA more current (510 mA vs 500 mA). For panels with mixed voltage wiring (24 V loops near vibration cables), use G3A. For clean panels with dedicated vibration wiring only, CVMAG3 is sufficient.

Q: Can I replace a CVMAG3 with a CVMAG3A without configuration changes?
A: Yes – drop-in replacement. The additional 1 kHz filter is software-selectable (default off). If you do not enable it, the board behaves exactly like CVMAG3. The TVS diodes are passive – no configuration needed.

Q: How do you test the over-voltage protection on refurbished G3A boards?
A: We apply 24 V DC to each input for 1 hour. Then we remove the over-voltage and apply 5.000 V DC. The board must read 5.000 V ±0.01 V. We also apply 120 V AC for 1 ms (simulated transient) using a surge generator. The TVS diodes must clamp to <35 V. About 8% of incoming G3A boards fail – TVS diodes shorted or open. Those are repaired (replace TVS array).

Q: I see a G3A board with a red sticker near the terminal block. What does that mean?
A: The red sticker indicates the board received an additional “repetitive surge” test: 1,000 surges at 120 V, 1 ms, 1 second apart. The TVS diodes must survive all surges with no degradation. Standard boards tested at 10 surges only. Red-sticker boards are for sites with frequent lightning or switching transients (steel mills, arc furnaces). We charge an extra $25 for red-sticker boards.

Q: My G3A board reads 0.5 V when input is grounded (should be 0 V). What failed?
A: The input protection TVS diode has leakage current (failed partially shorted). After a high-energy transient, the TVS may develop micro-shunts. Repair cost is $95. We replace the TVS array for that channel. Turnaround is 5 days. For multiple channels, replacement may be cheaper.

Q: Can I use the G3A board without an external signal conditioner (direct IEPE connection)?
A: No – same as CVMAG3. The G3A expects ±10 V from an external conditioner. IEPE accelerometers require 4 mA constant current and AC coupling – the G3A does not provide this. Use a separate conditioner (e.g., PCB 482C) between accelerometer and G3A. The G3A’s over-voltage protection will protect the conditioner output as well.

Q: How do I identify a counterfeit DS200CVMAG3A?
A: Genuine boards have “CVMAG3A” printed on the edge connector label. The TVS diodes are SMCJ30CA (surface mount, 8 total). Counterfeits often omit the TVS diodes or use smaller (SMBJ) devices with lower surge rating. Also check the input op-amps: genuine uses OPA4277 (precision). Fakes use LM324 (noisy, lower accuracy). We photograph the TVS diodes and op-amps on every board.

Q: What is the input impedance with the protection circuit active?
A: 50 kΩ nominal (CVMAG3 is 100 kΩ). The protection resistors (2x 25 kΩ in series) reduce impedance. For most external conditioners (output impedance <100 Ω), 50 kΩ load is fine (0.2% error). For high-output-impedance sensors (>1 kΩ), the 50 kΩ load may cause 2% error. In that case, use CVMAG3 (100 kΩ) or add a buffer amplifier.

Q: Does the additional 1 kHz filter affect phase response?
A: Yes – the 1 kHz filter (4-pole Bessel) adds 30° phase shift at 1 kHz. For orbit analysis (phase-matched channels), use the same filter setting on all channels. Do not mix filter settings. For amplitude-only monitoring, phase shift does not matter. The filter is optional – default off.

Q: What is the expected life of the TVS diodes?
A: TVS diodes degrade with each surge. Rated for 1,000 surges at 120 V (1 ms). For sites with frequent transients (e.g., daily contactor switching), the TVS may need replacement every 3-5 years. We offer a TVS refresh service ($45) – replace all 8 TVS diodes. For low-transient sites (office environments), TVS life exceeds 20 years.

Q: Can I use the G3A board with 4-20 mA vibration transmitters?
A: Yes – add a 250 Ω resistor across the input (convert 4-20 mA to 1-5 V). Scale in software. The G3A’s 50 kΩ input impedance will not load the resistor. The over-voltage protection protects the transmitter from accidental 24 V loops. For 4-20 mA, use DC coupling. The 1 kHz filter may be useful for noise.

Q: Do you offer a version with conformal coating for offshore use?
A: Yes – special order DS200CVMAG3AAB (acrylic coated). Lead time is 14-21 days. Cost adds 65. Coated version is recommended for offshore and coastal sites. The TVS diodes are sensitive to moisture leakage (can trigger at lower voltage). Coating prevents surface leakage. For offshore, also specify gold-plated terminal block (25 extra) to prevent screw corrosion. The G3A is often chosen for legacy offshore platforms where other boards cannot be used.

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