Description
ABB DO820
- Technical Specifications:
- Output Type: Electromechanical relay, SPST-NO (Form A)
- Channels: 8, each fully isolated from others and ModuleBus
- Rated Switching Voltage: Max 250 V AC, max 110 V DC (check label — some versions 125 V DC)
- Rated Switching Current: 3 A resistive @ ≤250 V AC / 110 V DC; cos φ > 0.4 for AC
- Minimum Applicable Load: 10 mA / 5 V DC
- Contact Material: Silver alloy (AgCdO or AgSnO₂)
- Operate / Release Time: Typ. 10 ms / 5 ms
- Mechanical Life: >10⁷ operations; Electrical life ≈10⁵ ops @ rated load
- Isolation Voltage: 2000 V AC channel-to-coil and channel-to-channel
- Relay Coil Supervision: Monitors 24 V ModuleBus; warning on loss
- Power Dissipation: Typ. 2.5 W (all relays ON)
- ModuleBus Current: +5 V typ. 70 mA; +24 V typ. 80 mA
- Max Field Cable Length: 600 m
- Operating Temp.: 0 °C to +55 °C
- MTU: S800 terminal unit (TU8xx series)
- Dimensions: 45 mm (W) × 119 mm (H) × 102 mm (D); weight ≈0.2 kg
- Certifications: CE, UL/cUL, ATEX Zone 2, marine
- Functional Features / Application / Material / Structure / Working Principle / Installation / Precautions: Same principles as DO802 — main differences: 3 A rating (vs 2 A), slightly higher coil power draw, same independent isolation per channel.
- Extra Precaution: 3 A resistive rating — for motor / lamp loads apply appropriate de-rating (motors: 3× inrush; tungsten lamps: 10–15× inrush). Use contact-protected version or interposing SSR/contactor for high inrush.
- Relay replacement interval should follow electrical life estimate based on actual switching frequency and load type.
