neptronic ST080S Actuator Instruction Manual

June 3, 2024

neptronic ST080S Actuator


  • Mounts easy on round & square shaft (with option –8).
  • External clutch for manual adjustments.
  • Maintenance free.
  • Position indicator.
  • Fail safe by Enerdrive System1 (on model 60, 65 & 80).
  • Auxiliary switches (on model 20 & 80).

Technical Data| __


| __


| __


| __


| __


| __


Auxiliary switches| No| No| Yes (2)| No| No| Yes (2)
Feedback| No| Yes| No| No| Yes| No
Fail safe – Enerdrive| No| Yes
Power consumption| 8 VA| 20VA Max, 8VA
Control signal| 3 wire / 2 position, 3 wire / 3 point floating| 2 wire / 2 position, 4 wire / 3 point floating
Power supply| 22 to 26 VAC or 28 to 32 VDC
Running time through 90º| 90 – 110 sec. (Fail-safe 20-35 sec)
Torque| 70 [8 Nm] at rated voltage
Electrical connection| 18 AWG [0.8 mm2] minimum
Inlet bushing| 2 inlet bushings: 13/16” [20.6mm]
Angle of rotation| 0 to 90 degrees, mechanically adjustable (factory set with 90º stroke)
Direction of rotation| Reversible, Clockwise (CW) or Counterclockwise (CCW) (factory set with CW direction)
Ambient temperature| -22ºF to +122ºF [-30ºC to +50ºC]
Storage temperature| -22ºF to +122ºF [-30ºC to +50ºC]
Relative Humidity| 5 to 95 % non condensing.
Ingress protection| IP22 equivalent to Nema type 2,

IP54 equivalent to Nema type 3R if water tight inlet bushings (not supplied NEP617) are installed

Weight| 3 lbs. [1.4 kg]
Warning: Do not press the clutch when actuator is powered

Dimension Inches Metric (mm)
A 1.50 38.1
B 3.64 92.5
C 6.60 167.5
D 3.02 76.8

We strongly recommend that all Neptronic® products be wired to a separate transformer and that transformer shall service only Neptronic® products. This precaution will prevent interference with, and/or possible damage to incompatible equipment.
When multiple actuators are wired on a single transformer, polarity must be observed. Long wiring runs create voltage drop which may affect the actuator performance.

Mechanical installation


  1. Manually close the damper blades and positioned the actuator at 0º or 90º.
  2. Slide the actuator onto the shaft.
  3. Tighten the nuts on the “U” bolt to the shaft with a 8mm wrench to a torque of 60 [6,7 Nm].
  4. Slide the mounting bracket under the actuator. Ensure free movement of the slot at the base of the actuator. The bracket pin must be placed in the mid distance of the slot.
  5. Fix the bracket to the ductwork with #8 self-tapping screws.

Wiring Diagramsneptronic-ST080S-Actuator-03 PC Board neptronic-ST080S-Actuator-04

Stroke adjustment
To adjust the stroke, move the adjustment screws at the desired position.

Read User Manual Online (PDF format)


Download This Manual (PDF format)

Download this manual  >>

neptronic User Manuals

Related Manuals