Series-285

Supported Applications

The Series 285 is a Smart Rotary Valve Positioner that accurately controls the valve stroke of rotary motion valves using a 4-20 mA DC input signal from the controller. A built-in microprocessor performs auto calibration, PID control and alarm functions and communicates over the HART protocol, while an analog feedback signal is output to stabilize the valve system.

• Rotary motion control valve and damper positioning
• Process loops requiring 4-20 mA input with HART communication
• Installations needing field-adjustable PID and valve characterization (linear, quick open, equal percentage)

The positioner is rated NEMA 4X (IP66) and can manually actuate the valve or damper. An air filter regulator can be mounted directly to the positioner, and tight shut-close and shut-open can be set in the programming menu. HART is a registered trademark of Fieldcomm Group, Inc.

Operating Conditions & Performance

The Series 285 takes a 4-20 mA DC input signal with an input impedance of 460 Ω max @ 20 mA DC, and runs on an air supply of 35 to 116 psi (2.4 to 8 bar). Ambient operating temperature is -30 to 85°C, and the rotary stroke is 0 to 90°.

• Linearity: ±0.5% FS
• Hysteresis: ±0.5% FS
• Sensitivity: ±0.2% FS
• Repeatability: ±0.3% FS
• Air consumption: .0004 scfm (.01 LPM) at 20 psig (1.4 bar) supply
• Flow capacity: 2.1 scfm (60 LPM) at 20 psig (1.4 bar) supply

The low air consumption reduces operating cost during steady control. The Series 285 weighs 6.4 lb (2.9 kg). Pneumatic and electrical terminations are an Air Connection of 1/4" NPT, a Gage Connection of 1/8" NPT and a Conduit Connection of 1/2" NPT. Split ranges such as 4 to 12 mA, with 12 to 20 mA, are available.

Configuration Options

Series 285 models share the same rotary-motion control electronics and HART communication, and differ by base designation and enclosure material to suit the actuator and installation environment.

• Aluminum enclosure models provide the standard housing.
• 316 SS enclosure models provide stainless steel construction for corrosive or washdown environments.

Mounting to a rotary actuator uses a fork lever and lever spring with a bracket, secured with four M8x1.25P hex bolts and four M8 plate washers.

Key Product Differences

The model number is built as 285ER-<base> - <communication> - <enclosure>. The lineup is:

• 285ER-S5 — HART communication, Aluminum enclosure.
• 285ER-D5 — HART communication, Aluminum enclosure.
• 285ER-S5SS — HART communication, 316 SS enclosure.