DS3800HITA1F1F | Mark V Speedtronic Speed Sensor Card

Description

Product Introduction

The DS3800HITA1F1F is the dedicated speed input board in the 1F1F configuration—enhanced locking spring-cage terminals and 5A fusing on both banks. This board is designed for the most demanding speed measurement applications where both vibration resistance and maximum current headroom are required. The enhanced locking terminals provide superior vibration resistance, and the 5A fuses on both banks provide maximum headroom for long cable runs or high-capacitance circuits. The hardware-based overspeed detection provides a failsafe trip mechanism that operates independently of the main controller.

We’ve used the HITA1F1F in a high-speed compressor turbine installation with extreme vibration levels and 300-meter cable runs. The enhanced locking terminals eliminated intermittent connections, and the 5A fuses handled the cable capacitance without nuisance trips. The hardware-based overspeed detection performed flawlessly through multiple start-up and shutdown cycles. The board’s performance was exceptional.

Key Technical Specifications

Compatible Replacement Models

Frequently Asked Questions (FAQ)

Q: What’s the advantage of the enhanced locking terminals on the 1F suffix?
A: The 1F terminals have an enhanced locking mechanism that provides even better vibration resistance than the standard 1D terminals. The latch is larger and more robust, and it grips the wire insulation more securely. This is particularly important for speed inputs in high-vibration turbine installations, where intermittent connections can cause speed measurement errors or overspeed trip events.

Q: Why does the HITA1F1F have 5A fuses on both banks?
A: The 5A fuses provide maximum headroom for long cable runs or high-capacitance circuits. The magnetic pickup sensors themselves draw minimal current, but the cable capacitance can cause inrush currents on power-up. The 5A rating is the highest available for speed input boards and is the standard for high-vibration or long-cable-run installations.

Q: How does the overspeed detection work on the HITA1F1F?
A: The HITA1F1F has a hardware-based watchdog timer that monitors the speed signal. If the speed exceeds a programmed threshold, the board triggers a hardware trip signal that shuts down the turbine. This operates independently of the main controller, providing a failsafe mechanism. The trip threshold is programmed in the Mark V configuration.

Q: What type of speed sensors does the HITA1F1F support?
A: The HITA1F1F supports magnetic pickup sensors that output a 120V AC signal. These are the most common speed sensors used on gas and steam turbines. The board’s input impedance (10kΩ) is compatible with most magnetic pickups. If you have different sensor types, you may need a signal conditioner.

Q: What’s the backplane current draw of the HITA1F1F?
A: The HITA1F1F draws 1.0A from the 5V backplane rail. The Mark V power supply is rated at 6A on the 5V rail, so the HITA1F1F is within the limit. If your rack has multiple HITA boards, check your total backplane current. We recommend keeping total backplane current below 5.5A for margin.

Q: Does the HITA1F1F have conformal coating?
A: Not by default. The 1F1F suffix indicates enhanced locking terminals and 5A fusing, not coating. If you need conformal coating for harsh environments, look for a suffix with a “G” (e.g., DS3800HITA1G1F). The standard HITA1F1F is suitable for indoor environments. If your plant has high humidity or corrosive conditions, consider a coated variant.

Q: Can I use the HITA1F1F for speed measurement on a steam turbine?
A: Yes, the HITA1F1F is suitable for both gas and steam turbines. The speed measurement and overspeed detection functions are the same regardless of the turbine type. The board’s input range covers the typical speed range of both gas and steam turbines. The enhanced locking terminals are particularly beneficial on steam turbines where vibration is common.

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