Siemens Powermite 599 MT Series, Powermite 599 MT SSC61.5U, Powermite 599 MT SSC61U Technical Instructions

Powermite 599

Technical Instructions

MT Series SSC Electronic

Valve Actuator, 24 Vac/dc
Proportional Control

Document No. 155-313P25

EA 599-15

January 12, 2018

Description

Features

Application

Product Numbers

The Powermite 599 MT SSC61U and SSC61.5U electroni c 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.

• UL listed for plenum installations.

• Direct-coupled installation without special tools.

• Manual override.

• Visual position indication.

The Powermite 599 MT SSC61 series electronic actuators and MT Series valves are
used in closed loop heat ing 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 t erminal units. The SSC61 series actuators accept a plenum cable or 3/8­inch flex conduit connection.

Table 1. Product Num bers.

Actuator Operating Mode Actuator Prefix Code

SSC61U

SSC61.5U

Non-spring Return

(Fail-in-Pl ace)

Spring Return

(Fail-Safe)

261

262

Ordering a Valve
Plus Actuator
Assembly

To order a com plete valve plus actuator assembl y 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 selecti on procedures.

To order an actuator only, use the product number.

Siemens Industry, Inc.

Technical Instructions MT Series SSC Electronic Valve Actuator, 24 Vac/dc Proportional Control
Document Number 155-313P25
January 12, 2018

Specifications

Operating voltage 24 Vac ±20%, 24 Vdc ±20%

Power requirements

Control characteristics

Functional operation

Agency certification

Ambient conditions

Physical characteri stics

Frequency 50/60 Hz ±2 Hz
Power supply 24 Vdc or earth ground isolating,

Class 2, 24 Vac transf ormer
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 operati on

Control signal (Y )
Voltage 0 to 10 Vdc (default) or 0 to 20 mA with

external 500 ohm, 0. 2W resi stor
Current 0.1 mA
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)
UL UL873 Listed
cUL Certified to CSA C22.2 No. 24-93
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)
Wiring Connecti on Plenum cable or 3/8-inch flex conduit
Weight 0.61 lb (0.27 kg)
Dimensions See Figure 7

Page 2 Siemens Industry, Inc.

MT Series SSC Electronic Valve Actuator, 24 Vac/dc Proportional Control Technical Instructions

Document Number 155-313P25

January 12, 2018

Operation

The stroke of the actuator shaft is proportional to the control signal on terminal Y.
A 0 Vdc control signal ret racts 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

Figure 1. SSC61.5U Electronic Spring Return

Mechanism.

occurs (tn) longer than 5
seconds, the capaci tor
discharges (td) and the actuator
returns to its norm al spring
return position.

CAUTION:

Before applying power, make certain a valve
is connected to the actuator.

If applying power to the act uator when a
valve is not connected, the actuator will
respond to a control si gnal 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 positi on indi cator (see
Figure 5 and Figure 6) on the top of the
actuator to the 0 positi on and verify that
the actuator shaft retracts completely.

3. Connect a v alve to the actuat or, and
reapply power. The actuator will return to
normal operation.

Siemens Industry, Inc. Page 3

Technical Instructions MT Series SSC Electronic Valve Actuator, 24 Vac/dc Proportional Control
Document Number 155-313P25
January 12, 2018

Operation,
Continued

Calibration Stroke

Mounting and
Installation

The SSC61x writes its calibration stroke parameters to nonvolatile memory on the first
start-up of the actuat or. 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 hol e on the circuit board
with the shorting bars.

3. With power appl ied to the unit, insert
and gently twist a flat-blade
screwdriver to electrically connect the
shorting bars (Fi gure 2). The SSC61x
then performs a new cali bration stroke.

4. Secure the terminal cover back in
place.

Figure 2. Manually Clearing Calibration

Stroke from Memory.

Mount the actuator in one of the allowable positions shown in Figure 3.

Wiring

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.

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.

Page 4 Siemens Industry, Inc.

MT Series SSC Electronic Valve Actuator, 24 Vac/dc Proportional Control Technical Instructions

Document Number 155-313P25

January 12, 2018

Wiring Diagrams

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)

Figure 4. SSC61U and SSC61. 5U Wiring.

Manual Override

Start-up

For manual posit ioning, use the
manual override knob in the
center of the position indicator,
See Figure 5.

Figure 5. Manual Override.

Check the wiring and the position indicat or
(Figure 6 ).

Positio n Indicator Output Shaft

0 Retracted
1 Extended

Figure 6. Top View of Position Indicator

(Shown in the 0 Position).

Siemens Industry, Inc. Page 5

Technical Instructions MT Series SSC Electronic Valve Actuator, 24 Vac/dc Proportional Control
Document Number 155-313P25
January 12, 2018

Troubleshooting
Service
Disposal

Dimensi ons

Check the wiring for proper connections.
If the actuator is inoperative, replace the unit.

The device is considered electrical and electronic equipment for
disposal in terms of the applicable European Directive and may not
be disposed of as domesti c garbage.

• Dispose of the dev ice through channels provi ded f or this
purpose.

• Comply wit h all local and currently applicable l aws and
regulati ons.

Figure 7. SSC61 Series Actuator Dimensions in Inches (Millimeters).

Service Envelop e

Minimum access space recommended:
8 inches (200 mm) above the actuator and beside the terminal cover.

Information in this publication is based on c urrent specific ations. The company reserves the right to make changes in specifications and models as
design improvements are introduced. Product or company n ames mentioned herein may b e the trademarks of their res pective ow ners.
© 2018 Siemens Industry, Inc.

Siemens Industry, Inc.

Building Technologies Division
1000 Deerfield Parkway
Buffalo Grove, IL 60089-4513
USA
Tel. [phone]

Your feedback is important to us. If you have

comments about this document, please send them

[e-mail]

Document No. 155-313P2 5

Printed in the USA

Page 6