GE DS3820EOMA

Key Parameters

• Channels: 8 digital outputs (sourcing – positive switching)

• Output Voltage: 24 V DC nominal (18–32 V DC)

• Output Current: 0.5 A per channel (continuous), 2 A peak (short duration)

• Total Current: 4 A per module (all channels combined)

• Isolation: 1500 V RMS (field-to-backplane); 500 V RMS between channels (optically isolated per channel)

• Protection: Per-channel electronic overcurrent protection (auto-restart after fault clears), short-circuit protection, thermal protection

• Diagnostics: Open-wire detection, short-circuit detection, per-channel LED status, over-temperature alarm

• Fail-Safe States: Software-configurable per channel (hold last state, go to ON, go to OFF) on communication loss

• Power: 24 V DC backplane power, ≤2.5 W (logic); external 24 V field supply required for outputs

• Operating Temperature: –40°C to +70°C

• Terminals: Screw-type (suffix-dependent)

Advantages

• Per-channel optical isolation – 500 V isolation between channels; prevents cross-talk and ground-loop issues when driving loads on different power supplies or phases.

• Electronic short-circuit protection – per-channel auto-restart protection eliminates external fuses; reduces downtime.

• Open-wire detection – detects broken output wiring or disconnected loads for proactive maintenance.

• Per-channel diagnostics – each output provides feedback on status (ON/OFF, short-circuit, open-wire, over-temperature) via the backplane.

• Software-configurable fail-safe – define output behavior (hold, ON, OFF) on communication loss for safe system shutdown.

• High channel density – 8 isolated outputs in a single slot; saves rack space.

• LED status indicators – per-channel visual indication for quick troubleshooting.

• Hot-swappable – replace without rack power-down.

Applications

• Solenoid control with mixed power sources – actuating valves powered from different 24 V supplies or in floating ground systems

• Relay control in distributed panels – driving interposing relays on different power distribution buses

• Motor control centers (MCC) – start/stop commands for motors with isolated control circuits

• Alarm annunciation – horns, beacons, and visual alarms on different ground references

• Packaging machinery – output control for actuators with separate power zones

• Building automation – lighting and HVAC damper control on different phases

• Offshore & marine – driving loads with potential ground potential differences

Competitor Comparison

The DS3820EOMA is the isolated-channel variant of the protected output family. Compared to the standard DS3820EMMA, it adds per-channel optical isolation (500 V) – critical for applications with mixed power supplies, floating grounds, or potential ground potential differences. Against competitor isolated output modules, the DS3820EOMA offers superior diagnostics (open-wire detection) and per-channel fail-safe configuration at a lower cost. For systems with distributed power sources or ground loops, the DS3820EOMA ensures reliable operation without cross-talk or ground-loop interference.

Selection Tips

• Choose DS3820EOMA when your loads are powered from different 24 V supplies or when ground potential differences exist between channels.

• Ideal for applications with floating grounds, distributed panels, or mixed power zones.

• Verify the output current requirement – provides 0.5 A per channel; use external relays for higher loads.

• Consider the fail-safe behavior – configure each channel for the safe state on communication loss.

• Not suitable for AC loads – use dedicated AC output modules.

• Ensure your PLC/DCS can read and process diagnostic data from the DS3820EOMA.

Precautions

• Isolated grounds: Do not tie the isolated commons of different channels together – this defeats the isolation and can create ground loops. The DS3820EOMA maintains 500 V isolation between channels only when commons are kept separate.

• Output current: Do not exceed 0.5 A per channel continuously. The auto-restart protection trips on overload – repeated trips may reduce lifespan.

• Inductive loads: Use external flyback diodes or surge suppressors for inductive loads (solenoids, relays) to prevent back-EMF damage.

• Wiring: Use appropriately sized wiring for 0.5 A output current. Keep output wiring separate from sensitive input signals.

• Power: Requires external 24 V field supply for outputs – ensure supply capacity for total current demand (up to 4 A per module).

• Fail-safe testing: Test fail-safe behavior during commissioning – confirm outputs go to the desired state on communication loss.

• Open-wire detection: Requires a minimum load current – very high-impedance loads may not trigger open-wire detection.

• Spare: Keep one spare DS3820EOMA for critical isolated output applications – the per-channel isolation may have longer lead times.