Siemens Powermite 599 MT Series Owner's manual

Powermite 599
Technical Instructions
Document No. 155-313P25
EA 599-15
January 12, 2018
MT Series SSC Electronic
Valve Actuator, 24 Vac/dc
Proportional Control
Siemens Industry, Inc.
Description The Powermite 599 MT SSC61U and SSC61.5U electronic valve actuators require a
24 Vac or 24 Vdc supply and a 0 to 10 Vdc control signal. They proportionally control
Powermite 599 MT Series valves with a 7/32-inch (5.5 mm) stroke and a threaded
valve bonnet that fits the actuators.
Features •UL listed for plenum installations.
•Direct-coupled installation without special tools.
•Manual override.
•Visual position indication.
Application The Powermite 599 MT SSC61 series electronic actuators and MT Series valves are
used in closed loop heating and cooling applications. They control hot or chilled water
or steam (<5 psi) for convectors, fan coil units, unit conditioners, radiation, reheat coils,
and similar terminal units. The SSC61 series actuators accept a plenum cable or 3/8-
inch flex conduit connection.
Product Numbers
Table 1. Product Numbers.
Actuator Operating Mode Actuator Prefix Code
SSC61U Non-spring Return
(Fail-in-Place) 261
SSC61.5U Spring Return
(Fail-Safe) 262
Ordering a Valve
Plus Actuator
Assembly
To order a complete valve plus actuator assembly from the factory, combine the
actuator prefix code with the suffix of the valve product number. See Technical Bulletin
TB251, Powermite 599 Series MT Series Terminal Unit Valve and Actuator Assembly
Selection (155-306P25) for selection procedures.
To order an actuator only, use the product number.

Technical Instructions MT Series SSC Electronic Valve Actuator, 24 Vac/dc Proportional Control
Document Number 155-313P25
January 12, 2018
Page 2 Siemens Industry, Inc.
Specifications
Power requirements Operating voltage 24 Vac ±20%, 24 Vdc ±20%
Frequency 50/60 Hz ±2 Hz
Power supply 24 Vdc or earth ground isolating,
Class 2, 24 Vac transformer
NOTE: Do not power more than
10 actuators with one
transformer.
SSC61U power consumption 2 VA
SSC61.5U power consumption 3 VA at ultra cap load,
2 VA at normal operation
Control characteristics Control signal (Y)
Voltage 0 to 10 Vdc (default) or 0 to 20 mA with
external 500 ohm, 0.2W resistor
Current 0.1 mA
Functional operation Running time
at 50/60 Hz 30 sec ±10%
Spring return, SSC61.5U only (Figure 1) ≈30 seconds
Nominal stroke 7/32-inch (5.5 mm)
Nominal force 67 lb (300N)
Stroke/signal relationship Linear
Capacitor charge time (Figure 1) maximum 180 seconds
Spring return (SSC61.5U only) Non-mechanical, electronic return fails
to stem up (0 position)
Agency certification UL UL873 Listed
cUL Certified to CSA C22.2 No. 24-93
Ambient conditions Ambient temperature
Operation 41°F to 122°F (5°C to 50°C) with
Transport and storage -13°F to 158°F (-25°C to +70°C)
Ambient humidity 0 to 90% rh (non-condensing)
Media temperature 35°F to 230°F (2°C to 110°C)
Physical characteristics Wiring Connection Plenum cable or 3/8-inch flex conduit
Weight 0.61 lb (0.27 kg)
Dimensions See Figure 7

MT Series SSC Electronic Valve Actuator, 24 Vac/dc Proportional Control Technical Instructions
Document Number 155-313P25
January 12, 2018
Siemens Industry, Inc. Page 3
Operation The stroke of the actuator shaft is proportional to the control signal on terminal Y.
A 0 Vdc control signal retracts the shaft. In the event of a power failure with no control
voltage, the SSC61U fails-in-place and holds its last position.
In the event of a power failure, the SSC61.5U returns to the stem up position. The
SSC61.5U includes an electronic return mechanism that functions as follows (Figure 1):
•At power-up (t0), a capacitor
must charge to its maximum
capacity (Max, tc). This will take
a maximum of 180 seconds,
during which time no actuator
movement occurs.
•Once the capacitor is fully
charged (tc), normal actuator
operation occurs.
•If a subsequent power failure
occurs (tn) longer than 5
seconds, the capacitor
discharges (td) and the actuator
returns to its normal spring
return position.
Figure 1. SSC61.5U Electronic Spring Return
Mechanism.
CAUTION:
Before applying power, make certain a valve
is connected to the actuator.
If applying power to the actuator when a
valve is not connected, the actuator will
respond to a control signal and the shaft will
extend until it reaches its maximum end stop.
Thereafter, it will not respond to any signal.
If this occurs:
1. Disconnect power.
2. Turn the manual position indicator (see
Figure 5 and Figure 6)on the top of the
actuator to the 0position and verify that
the actuator shaft retracts completely.
3. Connect a valve to the actuator, and
reapply power. The actuator will return to
normal operation.

Technical Instructions MT Series SSC Electronic Valve Actuator, 24 Vac/dc Proportional Control
Document Number 155-313P25
January 12, 2018
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 the 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 SSC61x
then performs a new calibration stroke.
4. Secure the terminal cover back in
place.
Figure 2. Manually Clearing Calibration
Stroke from Memory.
Mounting and
Installation Mount the actuator in one of the allowable positions shown in Figure 3.
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 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 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.

MT Series SSC Electronic Valve Actuator, 24 Vac/dc Proportional Control Technical Instructions
Document Number 155-313P25
January 12, 2018
Siemens Industry, Inc. Page 5
Wiring Diagrams
Figure 4. SSC61U and SSC61.5U Wiring.
G, G0 24 Vac or 24 Vdc operating
voltage
Y 0 to 10 Vdc control signal
G0 System neutral
G System potential
R1 500 ohm resistor
(optional for 0 to 20 mA
operation)
Manual Override For manual positioning, use the
manual override knob in the
center of the position indicator,
See Figure 5.
Figure 5. Manual Override.
Start-up Check the wiring and the position indicator
(Figure 6).
Figure 6. Top View of Position Indicator
(Shown in the 0 Position).
Position Indicator Output Shaft
0Retracted
1 Extended

Technical Instructions MT Series SSC Electronic Valve Actuator, 24 Vac/dc Proportional Control
Document Number 155-313P25
January 12, 2018
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. Product or company names mentioned herein may be the trademarks of their respective owners.
© 2018 Siemens Industry, Inc.
Siemens Industry, Inc.
Building Technologies Division
1000 Deerfield Parkway
Buffalo Grove, IL 60089-4513
USA
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Document No. 155-313P25
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Page 6
Troubleshooting Check the wiring for proper connections.
Service If the actuator is inoperative, replace the unit.
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
Figure 7. SSC61 Series Actuator Dimensions in Inches (Millimeters).
Service Envelope Minimum access space recommended:
8 inches (200 mm) above the actuator and beside the terminal cover.