Document No. 129-253
Installation Instructions
August 2, 2007
Siemens Building Technologies, Inc.
Page
3 of 4
Calibration Stroke
The SSC Series 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 (Figure 5).
3.
With power applied to the unit, insert and gently twist
a flat-blade screwdriver to electrically connect the
shorting bars. The SSC… 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 5. Manually Clearing Calibration Stroke from
SSC61U and SSC61.5U Nonvolatile Memory.
Wiring
•
All wiring must conform to NEC and local codes
and regulations.
•
Use earth ground isolating, step-down Class 2
transformers. Do
not
use autotransformers.
•
Determine the supply transformer rating by
summing the 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 with one
transformer.
NEUT
CONTROLLER
ACTUATOR
EARTH GROUND
ISOLATING CLASS 2
TRANSFORMER FOR
24 Vac POWER
120 Vac
1
0
Y2
Y1
G
24
Vac
EA0795R1
Y2: Retracts actuator
shaft
Y1: Extends actuator shaft
G: System potential
Figure 6. SSC81U NSR Floating Control.
EA1235R1
NEUT
CONTROLLER
EARTH GROUND
ISOLATING CLASS 2
24 Vac TRANSFORMER
120 Vac
24 Vac
ACTUATOR
G
Y2
Y1
G0
1
0
0
G, G0: 24 Vac
operating voltage
Y2: Retracts actuator shaft
Y1: Extends actuator shaft
G: System potential
G0: System neutral
Figure 7. SSC81.5U Floating Control SR
Hot-Switch.
CAUTION:
Terminals must be properly wired for
correct function and full life of the actuator.
EA1234R1
NEUT
CONTROLLER
EARTH GROUND
ISOLATING CLASS 2
24 Vac TRANSFORMER
120 Vac
24 Vac
ACTUATOR
G
Y2
Y1
G0
1
0
0
G, G0: 24 Vac operating voltage
Y2: Retracts actuator shaft
Y1: Extends actuator shaft
G: System potential
G0: System neutral
Figure 8. SSC81.5U Floating Control SR Neutral
Switching Applications.
NOTE:
For proper operation, it is recommended no
more than three actuators be assigned to any
single one control signal.
+
-
Y
G0
G
R1
24
Vac
NEUT
ACTUATOR
EARTH GROUND
ISOLATING CLASS 2
TRANSFORMER FOR
24 Vac POWER
120 Vac
ELECTRONIC
CONTROLLER
G, G0: 24 Vac operating voltage
Y: *0 to 10 Vdc control signal
G: System potential
G0: System neutral
R1: 500 ohm resistor
(optional for 0-20mA
operation)
Figure 9.
SSC61U, NSR and SC61.5U, SR,
0 to 10 Vdc Proportional Control Wiring Diagram.
*4 to 20 mA with
optional
resistor