Siemens Flowrite 599 Series Owner's manual

599 Series
Zone Valve Actuator
Technical Instructions
Document No. 155-710
February 7, 2023
SSA81U 24 Vac Electronic Valve
Actuator: Floating Control
Fail-in-Place
Siemens Industry, Inc.
Description
The 599 Series SSA81U Electronic Valve Actuator requires a 24 Vac power supply and
receives a floating control signal to control a valve. This actuator is designed to work
with 599 Series Zone Valves with a 1/10-inch (2.5 mm) stroke and a threaded valve
bonnet that fits the actuator.
Features
•Direct-coupled installation without tools
•Manual override with hex wrench
•Visual position indication
Application
For use in heating and cooling HVAC applications with Siemens 599 Series Zone
Valves that need 24 lb (105N) nominal force.
Product Number
Part Number
Description
Prefix Code
SSA81U
24 Vac
Floating
Normally Closed
244
Ordering
Information
To order a complete valve plus actuator assembly from the factory, combine the
actuator prefix code with the suffix of the valve product number.
To order a single actuator, use the product number (for example, SSA81U).

Technical Instructions SSA81U Electronic Valve Actuator
Document Number 155-710 24 Vac Floating Control
February 7, 2023
Page 2 Siemens Industry, Inc.
Warning/Caution Notations
WARNING
Personal injury/loss of life may occur if you do not perform a
procedure as specified.
CAUTION
Equipment damage may occur if you do not perform a
procedure as specified.
Specifications
Power supply
Operating voltage 24 Vac 20%
Frequency 50/60 Hz
Power consumption 0.8 VA
Function
Running time 150 seconds
Nominal stroke 1/10-inch (2.5 mm)
Nominal force 24 lb (105N)
Ambient conditions
Ambient temperature
Operation 41°F to 122°F (5°C to 50°C)
Transport and storage -13°F to 158°F (-25°C to 70°C)
Agency certification
Conformance
UL
EMC directive 89/336/EEC
Low Voltage direction 73/23/EEC
UL873, cUL Certified to Canadian
Standard C22.2 No. 24-93
Miscellaneous
Medium temperature 34°F to 230°F (1°C to 110°C)
Dimensions Inches (mm) 3.26 H×3.26 W×1.9 D (82×83×48)
Weight 9 oz (0.25 kg)
Accessory
Figure 1. Conduit Connector.
ASY97: Conduit connector, quantity one (1).
Service Kits
Figure 2. Terminal Plug and
Block Cover
ASY99: Terminal plug and terminal block
cover for SSA81U, quantity one
each.

SSA81U Electronic Valve Actuator Technical Instructions
24 Vac Floating Control Document Number 155-710
February 7, 2023
Siemens Industry, Inc. Page 3
Operation
The actuators can be driven manually to any position between 0 and 1 with a 3 mm hex
wrench. The control signal from the controller; however, will take priority over any
manual position.
Mounting and
Installation
Figure 3. Mounting Position.
Mount the actuator in one of the allowable positions shown in Figure 3.
NOTE: Vertical is the recommended 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.
Installation Instructions are included with the actuator.
Wiring
Figure 4. SSA81U Wiring Diagram.
•Do not use autotransformers.
•Use earth-ground isolating, step-down, Class 2, power supplies.
•Determine supply transformer rating by summing total VA of all actuators used.
•Use one transformer to power up to 10 actuators.

Technical Instructions SSA81U Electronic Valve Actuator
Document Number 155-710 24 Vac Floating Control
February 7, 2023
Page 4 Siemens Industry, Inc.
Manual Override
The actuators can be driven manually to any position between 0and 1with a 3 mm hex key.
The actuator will maintain its position until power is provided or restored. A control signal
from the controller, however, will take priority over any manual position.
NOTES:
•Do not perform a manual override while the power supply is connected: The actuator
will not track properly when the control signal is applied. A short power-off/power-on
sequence is recommended to recalibrate the actuator.
•To hold the actuator in the manually set position, the connecting cable must be
unplugged.
Position Indicator at 0
Position Indicator at 1
Figure 5. Position Indicator.
NOTE:
The 0and 1position
markings are for
reference only and not
for stroke measurement.

SSA81U Electronic Valve Actuator Technical Instructions
24 Vac Floating Control Document Number 155-710
February 7, 2023
Siemens Industry, Inc. Page 5
Start-Up
Check the wiring and the position indication. See Figure 5 for referred positions 0and 1on
the position indicator disc.
SSA81U Normally Closed
•When the position indicator disc is at the 0position the output shaft is extended
(two-way valve closed).
•When the position indicator disc rotates to position 1, the output shaft is retracted
(two-way valve open).
Figure 6. SSA81U Normally Closed.
(A) Turn the hex wrench counterclockwise and spindle retracts.
(B) Turn hex wrench clockwise and spindle extends.

Technical Instructions SSA81U Electronic Valve Actuator
Document Number 155-710 24 Vac Floating Control
February 7, 2023
Information in this publication is based on current specifications. The company reserves the right to make changes in specifications and models as
design improvements are introduced. Other product or company names mentioned herein may be the trademarks of their respective owners.
© 2005 Siemens Building Technologies, Inc.
Siemens Building Technologies, Inc.
1000 Deerfield Parkway
Buffalo Grove, IL 60089-4513
U.S.A.
Your feedback is important to us. If you have
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Document No. 155-710
Printed in the U.S.A.
Page 6
Troubleshooting
See Wiring for proper connections.
If the actuator does not provide full flow or full close off, check that the actuator is
properly attached to the valve. If not, turn power off, tighten the bonnet ring on to the
valve completely, and power up to recalibrate.
If the actuator becomes inoperative, replace it.
Disposal
The device is considered electrical and electronic equipment for
disposal in terms of the applicable European Directive and may not be
disposed of as domestic garbage.
•Dispose of the device through channels provided for this
purpose.
•Comply with all local and currently applicable laws and
regulations.
Dimensions
Inches (Millimeters)
Figure 7. Dimensions of the SSA81U Actuator in Inches (mm).
Service envelope
Minimum access space recommended:
8-inches (200 mm) above the actuator and beside the terminal plug.