Siemens Free Energy Band RCU61U Owner's manual

Free Energy Band
RCU61U
Technical Instructions
Document No. 155-328P25
October 6, 2016
Room Temperature Controller
for CAV Systems
Siemens Industry, Inc.
Description
The RCU microprocessor controlled CAV room controller is designed for air only, or air
and water heating and/or cooling systems. Controllers have proportional response.
Features
•Modulating P-control
•0 to 10 Vdc output for cooling
•Three-position output 24 Vac for heating
•Operating modes: Normal, Energy Saving, Frost Protection, Standby, and Off
•Active 0 to 10 Vdc input for setpoint shifting
•Operating mode changeover input for remote control
•Adjustable minimum limitation for cooling output
•Deadband between heating and cooling
•Operating voltage 24 Vac
Application
Individual room temperature control in HVAC installations that are heated or cooled.
Controlling these types of equipment:
•Valve actuators
•Air damper actuators
Product Number
RCU61U With three-position signal for heating, without operating mode selector

Technical Instructions RCU61U Room Temperature Controller
Document Number 155-328P25 for CAV Systems
October 6, 2016
Page 2 Siemens Industry, Inc.
Table 1. Equipment Combinations.
Product Number
Description
Technical
Instructions
SSB81U
Three-position valve
actuator
155-195P25
SSC81U
SSC81.5U*
155-314P25
SQS85.53U
155-308P25
SSB61U
0 to 10 Vdc valve
actuator
155-192P25
GLB16…
GDE16…
0 to 10 Vdc Air
damper actuator
155-187P25
* See Wiring Diagram.
Function
The controller measures the room temperature with its integrated sensor and maintains
the setpoint by delivering control commands.
At setpoint condition, the output is 0 Vdc. On increase in temperature in cooling mode,
the output signal goes up from 0 to 10 volts (Direct Acting –D.A.).
The proportional band or the switching differential can be 2°F or 7°F (1°C or 4°C) in
heating mode and 1°F or 3.5°F (0.5°C or 2°C) in cooling mode (selectable with DIP
Switch No. 4).
Heating-Cooling with
Minimum Limitation
Cooling
T Room or return air
temperature
L, L10 Output percentage
W Room temperature set
point
Xdz Deadband
XpH Proportional band
heating
XpC Proportional band
cooling
VR 0 to 100% minimum
limitation cooling output
Figure 1. RCU61U Function Diagram.
Minimum Limitation of
Cooling Signal
Using the potentiometer located on the circuit board, the cooling signal output can be
limited to a minimum value of 0 through 100%. This can be used to ensure a minimum
supply air volume. When used in connection with a VAV controller, this setting must be
taken into account. To set minimum limitation, use a screwdriver to adjust the
potentiometer (see Figure 2). Values on the scale are percentage of full operation.

RCU61U Room Temperature Controller Technical Instructions
For CAV Systems Document Number 155-328P25
October 6, 2016
Siemens Industry, Inc. Page 3
Minimum Limitation of
Cooling Signal,
Continued
Figure 2. Potentiometer Location.
Setpoint Shifting
Signal Inputs (Terminals 1 and 2) are used for outside temperature compensation.
Using a 0 to 10 Vdc signal, the setpoint can be shifted by ±22.5°F at 72°F. The neutral
position is at 5 Vdc and means no setpoint shift.
W Original setpoint
W1 New setpoint at 10V input
W2 New setpoint at 0V input
(V) Input voltage
Figure 3. Setpoint Shifting.
Setpoint Limit Stops
The room temperature setpoint can be limited in increments of 2°F (1°C) by using the
minimum and maximum setpoint limit stops. This prevents arbitrary setpoint
readjustments.
To set limit stops, remove the setpoint knob by pulling it straight off the shaft.
Reposition gray tabs for high and low stops in the holes around the perimeter of knob
as required. See Figure 4.
Figure 4. Setpoint Limit Stops.

Technical Instructions RCU61U Room Temperature Controller
Document Number 155-328P25 for CAV Systems
October 6, 2016
Page 4 Siemens Industry, Inc.
Operating Modes
The following operating modes are available:
Normal
When dry contact (3) is open, the setpoint knob setting takes over control and normal
mode is initiated.
Energy Saving
Energy saving mode can be initiated by activating the external operating mode
changeover switch, if DIP Switch No. 1 is set to ON.
In energy saving mode, the heating setpoint is 61°F (16°C) and the cooling setpoint is
82°F (28°C), independent of the position of the setpoint knob.
When the DIP switch is in energy saving mode and the fan speed control is set to
standby, the energy saving mode takes precedence over standby mode. Low fan speed
will be selected even though the fan switch is on standby.
Frost Protection
Frost protection mode can be initiated by activating the external operating mode
changeover switch, if DIP Switch No. 1 is set to OFF.
If the room temperature falls below 46°F (8°C), the controller will automatically switch to
frost protection mode. In that case, the heating valve opens and the room temperature
is maintained at a setpoint of 46°F (8°C). Any adjustments you make to the setpoint will
be ignored.
Operating Mode
Changeover Switch
A changeover switch can be connected to status input D1–GND. When the switch
closes its contact (caused by an open window, for instance), the operating mode will
change from normal operation or standby to energy saving mode (if DIP Switch No. 1 is
set to ON), or from normal operation or energy saving mode to standby (if DIP Switch
No. 1 is set to OFF).
The operating action of the switch (Normally Closed - NC or Normally Open - NO) can
be selected.
Mechanical Design
The unit consists of two parts:
•A plastic housing which accommodates the electronics, the operating elements, and
the built-in room temperature sensor.
•A controller base.
The housing snaps into the top and bottom of the mounting base.
The screw terminals are mounted on the base. The DIP switches and the potentiometer
are located at the rear of the unit. To access the DIP switches, remove the controller
from the controller base. See Figure 5.
Figure 5. DIP Switch Settings.

RCU61U Room Temperature Controller Technical Instructions
For CAV Systems Document Number 155-328P25
October 6, 2016
Siemens Industry, Inc. Page 5
Table 2. DIP Switches.
DIP Switch
No.
Meaning
Position ON
Position OFF
1
Operating mode changeover
using an external switch
Changeover between
normal operation and energy
saving mode
Changeover between normal
operation, energy saving mode,
and standby1
2
Operating action of switch for
external operating mode
changeover
Changeover activated when
contact of switch is closed
(NO)1
Changeover activated when
contact of switch is open
(NC)
3
Standby
OFF
Frost protection mode (heating
output ON at a setpoint of 46°F
(8°C)1
4
P-band
2°F (1°C) in heating mode1
1°F (0.5°C) in cooling mode1
7°F (4°C) in heating mode
3.5°F (2°C) in cooling mode
5
Dead zone (Xdz)
3.5°F (2°C)1
9°F (5°C)
6
Cooling signal output in energy
saving mode
Active
Inactive1
1Factory setting
Accessories
ARG70 Adapter Plate for 2 × 4-inch or 4 × 4-inch conduit boxes
QAH11.1 Changeover/remote sensor
Notes
•Check the settings of DIP Switches No. 1 through No. 6 and change them, if
required.
•After applying power, the controller resets, which takes about three seconds. It will
then be ready to operate.
•The unit can be located on a wall of the room to be conditioned. Do not mount in
direct sunlight or near other heat or refrigeration sources.
•Mounting height is approximately 47 inches (120 cm) above the floor. See Figure 6.
•The connecting wires can be run to the controller from a recessed conduit box.
•Only authorized personnel should open the controller.
Figure 6. Acceptable Mounting Height.

Technical Instructions RCU61U Room Temperature Controller
Document Number 155-328P25 for CAV Systems
October 6, 2016
Page 6 Siemens Industry, Inc.
Mounting,
Installation and
Commissioning
When mounting the unit, attach the controller base first. Then, make the electrical
connections and fit and secure the cover.
The controller must be mounted on a flat wall and in compliance with local regulations.
Any radiator valves in the room must be set to their fully open position upon start-up.
Outputs 9 (Opening), 10 (Closing), and 8 (Neutral) are used to drive three-position
actuators with a maximum running time of 150 seconds from the fully closed to the fully
open position.
When commissioning the controller, an opening signal of 200 seconds is delivered,
followed by a closing signal of 200 seconds to ensure the actuator will be fully closed.
When the actuator has reached the position calculated by the controller, a waiting time
of 30 seconds is observed to stabilize the outputs. The 0 to 10 Vdc cooling output is not
available until 400 seconds after controller power-up.
User input using setpoint knob results in instantaneous response. There is a one-
minute delay before changes made to temperature sensing and changeover are
implemented.
Drywall Mounting
1. Insert a small screwdriver into the bottom of the controller and press in the tab
located in the center of the controller.
2. Lift the bottom of the controller from the controller base and push up to remove the
cover from the two tabs located at the top of the controller base.
3. Remove the base from the back of the controller.
Figure 7. Controller Cover Separation.
4. Using the controller base as a template, mark the hole locations with a pencil.
5. Drill two 1/4-inch diameter holes for the plastic wall anchors.
6. Using a mallet, tap in the plastic wall anchors flush with the wall.
7. Pull the wiring through the opening in the upper portion of the controller base.
8. Level the mounting plate.
9. Using the two wood screws provided, fasten the controller base to the wall. The
controller is not position sensitive.
10. Pull the wiring through the controller base.
11. Position the controller housing over the two mounting lugs located at the top of the
controller base, and press down on the cover until the bottom lugs snap in place.

RCU61U Room Temperature Controller Technical Instructions
For CAV Systems Document Number 155-328P25
October 6, 2016
Siemens Industry, Inc. Page 7
Drywall Mounting,
Continued
12. Terminate the wires per wiring instructions located above the terminal block.
Figure 8. Wiring Termination.
13. Reattach the controller to the controller base.
Figure 9. Controller Reattachment.
14. Adjust the setpoint dial to the desired setting.
The installation is now complete.

Technical Instructions RCU61U Room Temperature Controller
Document Number 155-328P25 for CAV Systems
October 6, 2016
Page 8 Siemens Industry, Inc.
4 × 4-inch Electrical Wall
Box Mounting
An ARG70 wall plate adapter is required to mount an RCU61U controller to a 4 × 4-inch
electrical wall box. The ARG70 wall plate adapter is included with electrical wall box
mount models.
1. Insert a small screwdriver into the bottom of the controller and press in the tab
located in center of the controller.
2. Lift the bottom of the controller from the controller base and push up to remove the
cover from the two tabs located at the top of the controller base.
3. Separate the controller base (5) from the controller (6).
4. Using the four screws provided, fasten the wall box adapter (3) to the plaster ring
(2). (Plaster ring supplied by others.)
5. Flex the adapter mask (4) and snap it in place inside the wall box adapter (3).
6. Pull wires through the plaster ring (2).
7. Fasten the controller base (5) to the wall box adapter assembly (3) and (4) with the
two screws provided.
8. Follow Drywall Mounting Steps 6 through 14.
The installation is now complete.
Figure 10. 4 × 4-inch Electrical Wall Box Installation.
1 Electrical wall box
2 Plaster ring
3 Wall box adapter *
* Included with ARG70
4 Adapter mask *
5 Controller base
6 Controller

RCU61U Room Temperature Controller Technical Instructions
For CAV Systems Document Number 155-328P25
October 6, 2016
Siemens Industry, Inc. Page 9
2 × 4-inch Electrical Wall
Box Mounting
An ARG70 wall plate adapter is required to mount an RCU61U controller to a 2 × 4-inch
electrical wall box. The ARG70 wall plate adapter is included with electrical wall box
mount models.
1. Insert a small screwdriver into the bottom of the controller and press in the tab
located in the center of the controller.
2. Lift the bottom of the controller from the controller base and push up to remove the
cover from the two tabs located at the top of the controller base.
3. Separate the controller base (5) from the controller (6).
4. Using the two screws provided, fasten the wall box adapter (3) to the wall box (1).
5. Flex the adapter mask (4) and snap it in place inside the wall box adapter (3).
6. Fasten the controller base (5) to the wall box adapter assembly (3) and (4) with the
two screws provided.
7. Follow Drywall Mounting, Steps 6 through 14.
The installation is now complete.
Figure 11. 2 × 4-inch Electrical Wall Box Installation.
1 Electrical wall box
3 Wall box adapter *
4 Adapter mask *
* Included with ARG70
5 Controller base
6 Controller

Technical Instructions RCU61U Room Temperature Controller
Document Number 155-328P25 for CAV Systems
October 6, 2016
Page 10 Siemens Industry, Inc.
Maintenance
The room temperature controller is maintenance-free. If inoperable, replace the entire
unit.
Specifications
Power Supply
Operating voltage 24 Vac ±10%
Control action (P) Proportional
Frequency 50/60 Hz
Functional Data
Setpoint setting range 50°F to 85°F (10°C to 30°C)
Maximum control deviation at 68°F (20°C) ±0.7K
Switching differential heating SDH or 2°F or 7°F (1°C or 4°C)
P-band XpH (selectable)
Switching differential cooling SDC or 1°F or 3.5°F (0.5°C or 2°C)
P-band XpC (selectable)
Temperature setpoint shift ±22.5°F at 72°F setpoint
Control output, Terminal 4
Voltage 0 to 10 Vdc
Current ±1 mA
Control output, Terminals 9 and 10
Three-position output
Voltage 24 Vac ±20%
Current 2A maximum
Motor timing for heating output 150 seconds at 50/60 Hz
Status input D1
Contact sensing 6 to 15 Vdc/3 to 6 mA
Insulation against mains voltage 4 kV
Maximum number of contacts connected 50
in parallel
Status input, terminal 1
Setpoint shift of 22.5°F (12.5°C) 0 to 10 Vdc
Neutral position (no setpoint shift) 5 Vdc
Maximum copper cable length 16 AWG
For Input Signal Terminal 1 262 feet (80 m)
For Input Signal D1 262 feet (80 m)
Environmental
Conditions
Operation
Temperature 32°F to 122°F (0°C to 50°C)
Humidity <95% rh
Agency Approvals
UL listing UL 873
Conforms to CE requirements
cUL certified to Canadian Standard
C22.2 No. 24-93
General
Connection terminals 2 × 16 AWG or 1 × 14 AWG
Maximum 20 AWG
Use solid wires or prepared stranded wires.
Weight 0.5 lb (0.23 kg)
Housing color
Cover White
Base Gray

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. © 2016
Siemens Industry, Inc.
Siemens Industry, Inc.
Building Technologies Division
1000 Deerfield Parkway
Buffalo Grove, IL 60089
Tel. + 1 847-215-1000
Your feedback is important to us. If you have
comments about this document, please send them
to SBT_technical.editor.u[email protected]m
Document No. 155-328P25
Printed in the USA
Page 11
Wiring Diagram
1 Signal input "setpoint shift"
2 Measuring neutral
4 0 to 10 Vdc output/cooling
5 Ground for 0 to 10 Vdc
output/cooling
6 Operating voltage 24 Vac negative
7 Operating voltage 24 Vac positive
8 Positive control for 3-pos actuator
9 Return control signal open
10 Return control signal close
D1 Signal input for potential-free
operating mode changeover switch
GND Ground
Figure 12. Wiring Diagram.
NOTE: When wiring to an SSC81.5U actuator, an earth ground, isolating, Class 2
transformer is recommended. However, if you use an auto or polarized
transformer, the wiring polarity must be maintained through the controller to
the SSC81.5U for proper operation. For example, if G/G0 are reversed to the
controller, they must also be reversed to the actuator.
Dimensions
All dimensions in
inches
(millimeters)
Figure 13. RCU61U Dimensions.
Figure 14. Base Plate Dimensions.