Basic Specifications

• Manufacturer: Emerson (Westinghouse)

• Model: 3A99795H18

• Type: Analog Output Module (Ovation DCS I/O)

• Channels: 8 isolated channels, 14‑bit resolution

• Output Ranges: 4–20 mA (default), 0–10 VDC, ±5 VDC (software‑configurable)

• Isolation: 1500 V channel‑to‑channel and channel‑to‑ground

• Operating Temperature: 0 °C to 65 °C

• Power Consumption: 5.5 W typical (24 VDC ±10%)

• Mounting: Standard DIN rail, cabinet‑mounted

• Dimensions: 220 mm × 120 mm × 45 mm

• Weight: 1.42 kg

• Country of Origin: United States

• Certifications: CE, UL, cUL, EMC compliant

Key Features

1. High‑Accuracy Output: 14‑bit resolution with ±0.075% full‑scale precision for closed‑loop control.

2. Multi‑Range Flexibility: Configurable for 4–20 mA, 0–10 VDC, or ±5 VDC to drive diverse field devices.

3. Enhanced Isolation: 1500 V isolation reduces cross‑talk and improves noise immunity in high‑EMI environments.

4. Hot‑Swap Capability: Online replacement without system shutdown, minimizing maintenance downtime.

5. Comprehensive Diagnostics: Onboard LEDs (PWR, COMM, FAULT) and register‑based status for open‑circuit, short‑circuit, and over‑range detection.

6. Software‑Configurable: Set ranges, alarm limits, and failsafe states via Ovation tools; supports split‑range and redundant configurations.

7. Robust Hardware: Industrial‑grade components and conformal coating for long life in harsh conditions.

Installation & Configuration

1. Mounting: Install on DIN rail in a cabinet; ensure 50 mm clearance top/bottom for airflow.

2. Wiring: Connect field devices with shielded twisted‑pair cables; follow Ovation standards for analog signals.

3. Software Setup:

   • Launch Emerson Ovation configuration software.

   • Select 3A99795H18 from the device library.

   • Configure output type, failsafe values, and alarm thresholds.

   • Download configuration and verify with real‑time data.

4. Maintenance: Use Ovation diagnostics to reset faults, back up/restore configurations.

Safety & Compliance

• Electrical Safety: Disconnect power before installation/maintenance to avoid shock.

• Environmental: Dispose per local e‑waste regulations.

• Quality: Manufactured under Emerson’s ISO 9001 system, meeting EMC and safety standards.

Troubleshooting

• No Power: Check 24 VDC supply, connections, and user‑replaceable fuse.

• Communication Errors: Verify network wiring, termination, and controller compatibility.

• Output Inaccuracy: Check wiring, shielding, and device calibration; confirm range matches actuator.

• Fault LED On: Use Ovation diagnostics to isolate internal/external faults.

Warranty & Support