User Guide

Technical Instructions MT Series SSC Electronic Valve Actuator, 24 Vac Proportional Control
Document Number 155-313P25
June 7, 2013
Page 4 Siemens Industry, Inc.
Operation,
Continued
Calibration Stroke
The SSC61x writes its calibration stroke parameters to nonvolatile memory on the first
start-up of the actuator. Successive start-ups bypass the calibration stroke unless the
memory is manually cleared. If installing the actuator on a different valve (such as on a
replacement valve), manually clear the calibration stroke from memory as follows:
1. Remove the terminal cover using a
Phillips head screwdriver.
2. Locate hole on the circuit board with
the shorting bars.
3. With power applied to the unit, insert
and gently twist a flat-blade
screwdriver to electrically connect the
shorting bars (
Figure 2). The SSC61…
then performs a new calibration stroke.
4. Secure the terminal cover back in
place.
EA1155R1
WIRING TERMINAL
WITH REMOVABLE
TERMINAL BLOCK
Shorting
Bars
TERMINAL
COVER
AND SCREWS
Figure 2. Manually Clearing Calibration
Stroke from Memory.
Mounting and
Installation
Mount the actuator in one of the allowable positions shown in Figure 3.
EA0791R2
Figure 3. Mounting Position.
When mounting the actuator in a plenum, the proper cable must be attached to meet local
codes.
Allow 8 inches (200 mm) above the actuator and 8 inches (200 mm) behind the cable for
service.
Wiring
Use earth ground isolating, step-down Class 2 transformers. Do not use
autotransformers.
Determine supply transformer rating by summing total VA of all actuators used. The
maximum rating for a Class 2 step-down transformer is 100 VA.
Do not power more than 10 actuators by one transformer. (Use 0.5 amp fuse on
secondary per actuator.)
CAUTION:
Terminals must be properly wired for correct function and full life of the
actuator.