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Technical Instructions
Document No. 155-717
September 25, 2018
SKB/C/D 62UA Series
Electronic Valve Actuator 24 Vac
Proportional Control
Advanced Features
The Flowrite 599 Series SKB/C/D62UA Electronic Valve Actuator requires a 24 Vac
supply and receives a 0 to 10 Vdc or a 4 to 20 mA control signal to proportionally control
a valve. This actuator is designed to work with valves with a 3/4-inch (20 mm) or 1-1/2inch (40 mm) stroke.
• Direct-coupled installation requires no special tools or adjustments
• Visual and electronic stroke indication
• Die-cast aluminum housing
• Manual override
• Spring return to fail-safe position
• Automatic stroke calibration
• Direct or reverse acting
• Adjustable start and span
• Stroke limit control
• Choice of linear or equal-percentage flow characteristic
• Maintenance-free
These electronic actuators are designed to be used with Flowrite 599 Series valves with
either 3/4-inch (20 mm) stroke (SKB/D) or a 1-1/2 inch (40 mm) stroke (SKC) in liquid
and steam service applications; or other manufacturer's valves with appropriate
Universal Valve Linkage Kits.
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Technical Instructions Flowrite 599 Series SKB/C/D 62UA Electronic Valve Actuator Advanced Features
Document Number 155-717
September 25, 2018
Page 2 Siemens Industry, Inc.
Table 1. Product Numbers.
Warning/Caution Notations
Personal injury or loss of life may occur if you do not
perform a procedure as specified.
Equipment damage or loss of data may occur if you
do not perform a procedure as specified.
Operating voltage (SELV,PELV) 24 Vac ± 20%
Frequency 50 or 60 Hz
Power consumption
SKB62UA 17 VA/12W
SKC62UA 28 VA/20W
SKD62UA 17 VA/12W
Type of control (proportional) 0 to 10 Vdc; 4 to 20 mA;
or 0 to 1000 ohms
Running time Opening: Closing:
SKB62UA 120 seconds 15 seconds
SKC62UA 120 seconds 20 seconds
SKD62UA 30 seconds 15 seconds
Spring-return time Closing:
SKB62UA 15 seconds
SKC62UA 20 seconds
SKD62UA 15 seconds
Nominal stroke
SKB62UA 3/4-inch (20 mm)
SKC62UA 1-1/2-inch (40 mm)
SKD62UA 3/4-inch (20 mm)
Position force
SKB/C 62UA 2800N
SKD62UA 1000N
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Flowrite 599 Series SKB/C/D 62UA Electronic Valve Actuator Advanced Features Technical Instructions
Document Number 155-717
September 25, 2018
Siemens Industry, Inc. Page 3
Terminal Y
Voltage 0 to 10 Vdc
Input impendence 100K ohm
Current 4 to 20 mA
Input impedance 240 ohm
Signal resolution <1%
Hysteresis <1%
Terminal Z
Resistance 0 to 1000 ohm
Override control functions
Z not connected No function (priority at Terminal Y)
Z connected directly to G Maximum stroke 100%
Z connected directly to G0 Minimum stroke 0%
Z connected to M via 0 to 1000 ohm Linear or equal percentage
Terminal U
Voltage 0 to 9.8 Vdc ± 2%
Load impedance >500 ohm
Current 4 to 19.6 mA ± 2%
Load impedance <500 ohms
Media temperature
SKD 20°F to 300°F (-7°C to 150°C)
SKB/C 20°F to 337°F (-7°C to 170°C)
Operation To IEC 721-3-3
Environmental conditions Class 3K5
Temperature
SKD 5°F to 122°F (-15°C to 50°C)
SKB/C 5°F to 130°F (-15°C to 55°C)
Humidity 5% to 95% rh
Transport To IEC 721-2-1
Environmental conditions Class 3K5
Temperature 22°F to 149°F (-5°C to 65°C)
Humidity <95% rh
Storage To IEC 721-3-1
Environmental conditions Class 1K3
Temperature
SKD 5°F to 122°F (-15°C to 50°C)
SKB/C 5°F to 130°F (-15°C to 55°C)
Humidity 5% to 95% rh
UL Listed to UL873
C-UL Certified to Canadian standard
C22.2 No. 24-93
Meets CE requirements:
EMC Directive 89/336/EEC
C-tick N474
Protection standard IP54 to EN 60 529
Protection Class III to EN 60 730
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Technical Instructions Flowrite 599 Series SKB/C/D 62UA Electronic Valve Actuator Advanced Features
Document Number 155-717
September 25, 2018
Page 4 Siemens Industry, Inc.
Materials
Actuator housing and bracket Die-cast aluminum
Housing box and manual adjustor Plastic
Conduit opening 1/2-inch NPSM
Dimensions See Figure 23, Figure 24, Figure 25
and Figure 26.
Weight
SKB62UA 18.9 lbs (8,60 kg)
SKC62UA 22.5 lbs (10,00 kg)
SKD62UA 8.5 lbs (3,85 kg)
NEMA Rating NEMA 1 (Interior only)
See Accessories
Direction of Operation
Direct acting / reverse acting 0 to 10 Vdc; 10 to 0 Vdc
4 20 mA; 20 to 4 mA
0 to 1000 ohm/1000 to 0 ohm
Stroke Limit Control
Range of lower limit 0% to 45% adjustable
Range of upper limit 100% to 55% adjustable
Sequence Control
Starting Point of Sequence (Start) 0 to 15V adjustable
Operating Range of Sequence (Span) 3 to 15V adjustable
Figure 1. Auxiliary Switch.
ASC1.6 Auxiliary switch
• Sends a signal to indicate that the valve is
in the 0% stroke position.
• The switching point is fixed at the 0%
stroke position.
Switching capacity 24 Vac
4A resistive,
2A inductive
Lowest recommended current 10 mA
Figure 2. Stem Heating Element.
ASZ6.6 The stem heating element prevents
the formation of ice on the stem when the
medium temperature drops below 32°F (0°C).
It is suited for universal use with valves having
a stem or spindle diameter of 10 or 14 mm.
Operating voltage 24 Vac/dc ± 20%
Power consumption ≤ 40 VA/30W
Figure 3. SKB/C Weather Shield.
599-10065 The SKB/C actuator is UL listed to
meet NEMA Type 3R requirements (a degree
of protection against rain, sleet, and damage
from external ice formation) when installed with
this weather shield and outdoor-rated conduit
fittings in the vertical position. See Service Kits
for replacement ultraviolet resistant cable ties.
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Flowrite 599 Series SKB/C/D 62UA Electronic Valve Actuator Advanced Features Technical Instructions
Document Number 155-717
September 25, 2018
Siemens Industry, Inc. Page 5
Figure 4. SKD Weather Shield.
599-10071 The SKD actuator is UL listed to
meet NEMA TYPE 3R requirements (a degree
of protection against rain, sleet, and damage
from external ice formation) when installed with
this weather shield and outdoor-rated conduit
fittings in the vertical position. See Service Kits
for replacement ultraviolet resistant cable ties.
Figure 5. Valve Retrofit Kit.
Universal Retrofit Kit
Kit contains the parts needed to adapt a valve
to the following Siemens 599 Series Flowrite
actuators: SKB, SKC, SKD, SQX. Selected
valves from the following manufacturers can
also be accommodated: Honeywell, Johnson
Controls, and Siebe. See your local Siemens
representative for details.
Circuit board replacement 4 668 5751 8
Manual override kit 4268 5510 8
Plastic wiring compartment cover 4 104 5582 8
Stem retainer kit
Contains one stem nut (Figure 7, Item 6) and one stem retainer clip.
2-1/2 and 3-inch valves 599-10048
4, 5, and 6-inch valves 599-10049
Retainer clamp kit 599-10200
Ultraviolet (UV) resistant cable ties (pkg. of 8) 538-994
WARNING:
This product contains a spring under high compression. Do not
attempt to disassemble the actuator.
Figure 6. SKB/C Valve Parts.
1. Manual Adjuster
2. Pressure Cylinder
3. Piston
4. Reservoir
5. Pressure Chamber
6. Pump
7. Return Spring
8. Bypass Valve
9. Coupling
10. Valve Stem
11. Inner Valve
12. Position Indicator (0 to 1)