DS3800HLCA1D1E | Mark V Speedtronic Position Sensor Card

Description

Product Introduction

The DS3800HLCA1D1E is the dedicated LVDT/RVDT input board in the 1D1E configuration—locking spring-cage terminals with 2.5A fusing on Bank 1 and 5A fusing on Bank 2. This board processes position feedback signals from LVDT and RVDT sensors, providing the 120V AC excitation and conditioning the return signals for accurate position feedback. The locking terminals ensure reliable connections in high-vibration environments, and the asymmetric fusing provides maximum headroom for long cable runs or high-capacitance circuits on Bank 2 while maintaining robust protection on Bank 1.

We’ve used the HLCA1D1E in a large steam turbine installation where the LVDT sensors were located 200 meters from the control cabinet. The 5A bank handled the cable capacitance without nuisance trips, and the 2.5A bank was used for the sensors with shorter cable runs. The locking terminals prevented intermittent connections from the LVDT sensors, providing stable position feedback for the valve control loops.

Key Technical Specifications

Compatible Replacement Models

Frequently Asked Questions (FAQ)

Q: Why does the HLCA1D1E have mixed fusing (2.5A and 5A)?
A: The mixed fusing allows you to match protection to different sensor requirements. The 2.5A bank is for standard LVDT connections with moderate cable runs. The 5A bank is for sensors with long cable runs (over 100 meters) where cable capacitance can cause inrush currents. The 5A rating provides maximum headroom for these applications while still protecting the board.

Q: What’s the advantage of the locking terminals on the 1D suffix?
A: The locking terminals have a plastic latch that prevents the wire from pulling out under vibration. This is particularly important for LVDT position sensors, where intermittent connections can cause position feedback errors or valve position drift. The locking mechanism is a simple but effective solution for high-vibration environments.

Q: What type of LVDT sensors does the HLCA1D1E support?
A: The HLCA1D1E supports standard 120V AC-excited LVDT and RVDT sensors used in turbine control applications. The board provides the 120V AC excitation and conditions the secondary voltages to provide a position feedback signal. The board’s input impedance (10kΩ) is compatible with most industrial LVDT sensors.

Q: What’s the accuracy of the position measurement on the HLCA1D1E?
A: The HLCA1D1E provides position measurement with an accuracy of ±0.1% of full scale. This is sufficient for most turbine valve position control applications. The board uses precision signal conditioning circuitry to ensure accurate position feedback.

Q: Does the HLCA1D1E have conformal coating?
A: Not by default. The 1D1E suffix indicates locking terminals and mixed fusing, not coating. If you need conformal coating for harsh environments, look for a suffix with a “G” (e.g., DS3800HLCA1G1E). The standard HLCA1D1E is suitable for indoor environments. If your plant has high humidity or corrosive conditions, consider a coated variant.

Q: What’s the backplane current draw of the HLCA1D1E?
A: The HLCA1D1E draws 1.2A from the 5V backplane rail. The Mark V power supply is rated at 6A on the 5V rail, so the HLCA1D1E is within the limit. If your rack has multiple HLCA boards, check your total backplane current. We recommend keeping total backplane current below 5.5A for margin.

Q: Can I use the HLCA1D1E with LVDT sensors from different manufacturers?
A: The HLCA1D1E is designed for standard 120V AC-excited LVDT sensors. Most industrial LVDT sensors from major manufacturers (e.g., Schaevitz, Solartron) are compatible. However, always verify the sensor’s excitation requirements and output characteristics before installation. Consult the sensor data sheet and compare with the HLCA1D1E specifications. The high fuse rating on Bank 2 makes this variant suitable for long-distance LVDT installations.

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