DS200SHVMG1 | GE DS200 Valve Position Monitor In Stock

Description

Product Core Brief

• Model: DS200SHVMG1
• Brand: General Electric (GE)
• Series: Mark V DS200
• Core Function: Servo valve condition monitoring with diagnostic outputs
• Product Type: Valve Health Monitor (1 channel)
• Key Specs: Monitors drive current and position feedback | Detects stiction | Logs cycles | Alert output
• Condition: New Surplus.

Product Introduction

The DS200SHVMG1 is a servo valve condition monitoring board for GE’s Mark V DS200 series, used in Speedtronic turbine control systems. It continuously monitors the relationship between drive current (0–200 mA) and valve position (4–20 mA feedback) to detect degradation before failure.

The SHVMG1 installs between the existing servo valve driver (SHVIG1, SHCAG1, or SDCC) and the valve. It passes through the drive current and feedback signals without interference (0.1% burden). Onboard diagnostics analyze the transfer function: deadband (stiction), response time, cycle count, and position deviation. When parameters exceed configurable thresholds, the board closes a relay output (dry contact) for remote alarming. Use it for predictive maintenance on critical valves.

Key Technical Specifications

Key Selling Points & Differentiators

• Predictive maintenance for servo valves – Detects stiction and degradation before valve fails. Schedule maintenance during outages, not after trips.
• Non-intrusive monitoring – Pass-through design. Does not interfere with existing control loop (0.1% burden on drive current, 0.02% on feedback). Install in series without re-tuning.
• Cycle counting – Logs total valve cycles (one cycle = 10% position change). Know when valve reaches manufacturer-recommended service interval.
• Health index output – 4–20 mA analog signal proportional to calculated valve health (0–100%). Connect to DCS or PLC for trending.
• Configurable thresholds – DIP switches set alarm thresholds: deadband (2, 4, 6, 8, 10%), response time (100, 200, 500, 1000, 2000 ms), position deviation (5, 10, 15, 20%).
• Alert relay output – Form C relay closes when any threshold exceeded. Wire to annunciator or PLC.
• Non-volatile cycle counter – EEPROM retains count through power loss. Reset via push-button or external signal.
• QC includes stiction detection verification – Simulated valve with known deadband, verify detection accuracy <±0.5% of span.
• 2-year warranty

Frequently Asked Questions (FAQ)

Q: Can the SHVMG1 be added to an existing control loop without re-tuning the PID?
A: Yes. The pass-through burden is 5Ω on drive current and 50Ω on feedback. At 200 mA, drive current burden is 1 V drop (insignificant). Feedback burden at 20 mA is 1 V drop. For a typical 24 V loop, this is negligible. The PID loop will not notice the monitor.

Q: What is stiction, and why is it bad?
A: Stiction (sticky friction) is when the valve does not move until the drive current changes enough to overcome static friction. The valve then jumps past the desired position. Causes oscillation, wear, and poor control. The SHVMG1 measures the drive current change between direction reversals. If stiction exceeds threshold (e.g., 5%), alarm triggers.

Q: How does the health index work?
A: The board calculates a weighted score based on: deadband (30% of score), response time (30%), position deviation (20%), cycle count (10%), output current deviation (10%). 4–20 mA output = (score/100)*16 + 4. Example: 100% healthy = 20 mA, 50% healthy = 12 mA, 0% healthy (alarm threshold) = 4 mA. Use for trending in SCADA.

Q: How do I set the alarm thresholds?
A: Four DIP switches. Switch 1-2: deadband (00=2%, 01=4%, 10=6%, 11=8%, plus position for 10%). Switch 3-4: response time (00=100ms, 01=200ms, 10=500ms, 11=1000ms, plus position for 2000ms). Position deviation and current deviation are fixed at 10% (not adjustable on base model; for adjustable thresholds, use SHVMG1A). Configuration guide included.

Q: Does the SHVMG1 work with valves that use 4–20 mA drive current instead of 0–200 mA?
A: No. The drive current monitor input expects 0–200 mA (typical torque motor valve). For 4–20 mA drive, use the SHVMG2 variant (special order). Contact us for details.

Q: What is the cycle count definition?
A: One cycle = 10% change in valve position (either direction). The board counts both increasing and decreasing changes. Example: valve moves from 50% to 60% = 1 cycle. Move back to 50% = another cycle. Rate limit: ignores changes <5% to avoid noise.

Q: What QC tests are specific to the SHVMG1?
A: Nine tests:

1. Drive current accuracy: 0–200 mA, error <±1%
2. Feedback accuracy: 4–20 mA, error <±0.5%
3. Stiction detection: inject simulated deadband (2%, 5%, 10%), verify alarm threshold accuracy ±0.5%
4. Response time measurement: inject step change, measure detection accuracy ±10 ms
5. Cycle counting: 1000 cycles simulated, verify count matches
6. Health index output: 0–100% in 10% increments, verify 4–20 mA output accuracy ±0.2 mA
7. Alarm relay: verify closure at configured thresholds
8. Isolation: alarm relay to logic at 1800 VAC
9. Burn-in: 72 hours at +65°C, continuous monitoring of simulated valve

Q: What shipping protection?
A: Anti-static bag, ESD foam cradle, double-wall box with “ESD SENSITIVE,” “FRAGILE” labels. Each board ships individually. Configuration DIP switch guide included. Spare fuses included. External power supply not included (order separately)

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