Emerson MultiFlex RTU User manual

MultiFlex RTU Rooftop Controller
Installation and Operation Manual
026-1706 Rev 3

EEmerson Digital Solutions
1065 Big Shanty Road NW, Suite 100
Kennesaw, GA 30144 USA
770-425-2724 • 1-800-829-2724
www.climate.emerson.com
Email: [email protected]
ALL RIGHTS RESERVED.
The information contained in this manual has been carefully checked and is believed to be accurate. However, Emerson
assumes no responsibility for any inaccuracies that may be contained herein. In no event will Emerson be liable for any
direct, indirect, special, incidental, or consequential damages resulting from any defect or omission in this manual, even
if advised of the possibility of such damages. In the interest of continued product development, Emerson reserves the
right to make improvements to this manual, and the products described herein, at any time without notice or obligation.
READ ALL INSTRUCTIONS CAREFULLY
If the equipment is not used in the manner specified by the manufacturer, the protection provided
by the equipment may be impaired.
SAVE THIS INSTRUCTION MANUAL
This instruction manual contains important operating instructions for the MultiFlex RTU rooftop
control board.
f

Contents MultiFlex RTU Operator’s Guide • 5
Contents
1 OVERVIEW OF THE MULTIFLEX RTU ................................................................................................................ 1
1.1. DIFFERENCES BETWEEN THE MULTIFLEX RTU AND ARTC ....................................................................................... 1
1.2. THE RTU’S I/O POINTS ................................................................................................................................................ 1
1.3. INDEPENDENT SYSTEM CONTROL ................................................................................................................................ 1
2 MOUNTING AND POWERING ................................................................................................................................. 2
2.1. SNAP-TRACK INSTALLATION........................................................................................................................................ 2
2.2. THE PLUG-IN OUTPUT BOARD ..................................................................................................................................... 3
2.3. POWERING THE MULTIFLEX RTU BOARD ................................................................................................................... 3
2.3.1. Choosing Transformer Sizes ................................................................................................................................. 4
2.3.2. MultiFlex RTU Power Wiring............................................................................................................................... 4
2.3.2.1. New-Style MultiFlex RTU Boards (with Isolated Power Supply) ..................................................................................... 4
2.3.2.2. Old-Style MultiFlex RTU Boards No Isolated Power Supply) .......................................................................................... 5
2.3.3. Wire Types and Maximum Distances.................................................................................................................... 6
2.4. THE MULTIFLEX RTU BATTERY AND BATTERY ENABLE JUMPER ............................................................................. 7
3 THE I/O NETWORK .................................................................................................................................................... 8
3.1. WIRING TYPES.............................................................................................................................................................. 8
3.1.1. Daisy Chains ......................................................................................................................................................... 8
3.1.2. Network ID Numbers ............................................................................................................................................ 8
3.1.2.1. Numbering the MultiFlex RTU .......................................................................................................................................... 9
3.1.3. Setting the Baud Rate............................................................................................................................................ 9
3.1.4. Setting the Terminating Resistance Jumpers ........................................................................................................ 9
4 RTU INPUT AND OUTPUT SETUP......................................................................................................................... 10
4.1. THE INPUTS................................................................................................................................................................. 10
4.1.1. MultiFlex RTU Fixed Input Locations ................................................................................................................ 10
4.1.2. Auxiliary Input Types .......................................................................................................................................... 10
4.1.3. Wiring Sensors to the MultiFlex RTU................................................................................................................. 11
4.1.3.1. Wiring ............................................................................................................................................................................... 11
4.1.3.2. Sensor Wiring Types ........................................................................................................................................................ 11
4.1.3.3. Input Type Dip Switches .................................................................................................................................................. 12
4.1.4. Input Connection When Replacing ARTC with RTU .......................................................................................... 12
4.1.5. On-Board Power Connection.............................................................................................................................. 12
4.1.5.1. Current Ratings for On-Board Power Sources ................................................................................................................. 13
4.1.5.2. Powering Sensors Requiring 24VAC Off the Power Transformer................................................................................... 13
4.2. THE OUTPUTS ............................................................................................................................................................. 13
4.2.1. MultiFlex RTU Fixed Outputs............................................................................................................................. 13
4.2.2. MultiFlex RTU Auxiliary Output Types .............................................................................................................. 14
4.2.3. Wiring Outputs to Points..................................................................................................................................... 14
4.2.4. Output Fail-Safe Dip Switches............................................................................................................................ 15
4.2.5. Relay Output Ratings and Fuse Protection......................................................................................................... 15
4.3. ANALOG OUTPUTS...................................................................................................................................................... 16
4.3.1. Wiring the RTU Analog Output Points ............................................................................................................... 16
5 BOARD STATUS LEDS ............................................................................................................................................. 17
5.1. STATUS LED .............................................................................................................................................................. 17
5.2. TX AND RX LEDS...................................................................................................................................................... 17
5.3. THE CODE A LED ...................................................................................................................................................... 17

6 • MultiFlex RTU Operator’s Guide 026-1706 Rev 3
5.4. THE CODE B LED ...................................................................................................................................................... 18
5.5. RELAY OUTPUT LEDS................................................................................................................................................ 18
6 SOFTWARE OVERVIEW ......................................................................................................................................... 19
6.1. INTRODUCTION TO ZONE CONTROL............................................................................................................................ 19
6.2. TEMPERATURE CONTROL ........................................................................................................................................... 19
6.2.1. Setpoints .............................................................................................................................................................. 19
6.2.1.1. Setpoint Deadbands .......................................................................................................................................................... 19
6.2.1.2. Stage ON and OFF Delays................................................................................................................................................ 19
6.2.1.3. Summer/Winter and Occupied/Unoccupied Setpoints ..................................................................................................... 19
6.3. FAN CONTROL ............................................................................................................................................................ 20
6.4. DEHUMIDIFICATION AND HUMIDIFICATION CONTROL ............................................................................................... 20
6.4.1. Dehumidification Control ................................................................................................................................... 20
6.4.2. Humidification Control ....................................................................................................................................... 20
6.5. ECONOMIZATION......................................................................................................................................................... 20
6.5.1. Analog Economizers............................................................................................................................................ 21
6.6. CURTAILMENT ............................................................................................................................................................ 21
6.7. REVERSING VALVE CONTROL .................................................................................................................................... 21
6.8. STAND-ALONE OPERATION ........................................................................................................................................ 21
6.9. SENSOR FAILURES ...................................................................................................................................................... 22
7 THE MULTIFLEX RTU HAND-HELD INTERFACE........................................................................................... 23
7.1. RTU HAND-HELD TERMINAL STATUS SCREENS........................................................................................................ 23
7.2. RTU MAIN MENU....................................................................................................................................................... 24
7.3. STATUS MENU ............................................................................................................................................................ 24
7.4. CONTROL MENU ......................................................................................................................................................... 25

Differences Between the MultiFlex RTU and ARTC Overview of the MultiFlex RTU • 1
1 Overview of the
MultiFlex RTU
The MultiFlex Rooftop Unit Board (RTU) (P/N
810-3062) is a “smart” combination input/output
board designed to control package rooftop
HVAC units. The MultiFlex RTU is capable of
controlling heat and cool stages, fans,
humidification and dehumidification devices,
economizers using on-board I/O and control
algorithms, as well as monitor and interact with
other building control systems and peripherals
(such as smoke alarms and CO2 sensors).
1.1. Differences Between the
MultiFlex RTU and ARTC
The MultiFlex RTU is a hardware replacement
for Emerson’s ARTC rooftop unit control
boards, which are now discontinued. The RTU
firmware is in every way identical to the ARTCs,
and is compatible with both Einstein BX and the
REFLECS BCU controllers. The only difference
between the RTU and ARTC is the RTU uses the
MultiFlex hardware platform, which is smaller
and more robust.
1.2. The RTU’s I/O Points
The compact size of the RTU allows technicians
to easily field-mount the RTU in a rooftop unit
or enclosure close to it, allowing for easy local
connection of sensors and transducers. The
board has eight analog inputs, pre-configured for
quick connection to space temperature sensors,
supply and return air temperature sensors, and
fan and compressor proofs. Its eight relay
outputs, rated 2.0 amps max, are used for
activating and deactivating fans, heat and cool
stages, economizers, and other systems or
devices.
1.3. Independent System
Control
The RTU can control a rooftop unit
independently without the need of a central
controller (such as Emerson’s Einstein BX
Refrigeration Controller). However, the RTU is
designed to interface with an Einstein BX or
BCU to allow it to work with other RTUs
together to control large zones. Networking RTU
to a central controller also allows you to view
status on Einstein & UltraSite32 status screens,
report alarms, and control dehumidification.
The RTU’s configuration can be programmed
either with ans Emerson Hand-Held Terminal
(HHT) or through the Einstein front panel.
LEGEND
1 INPUT POWER
(24VAC)
9 RS485 I/O TERMINATION
JUMPERS
2 RS485 I/O NETWORK 10 HAND-HELD TERMINAL
JACK
3 RTU INPUTS 1-8 11 RELAY OUTPUT
CONNECTORS
4 RTU INPUTS 9-16 (NOT
ACTIVE FOR RTU)
12 RELAY OUTPUT FUSES
(2A rated, 250V slow-blow)
5 NETWORK ID DIP
SWITCHES (S3, S4)
13 RELAY STATUS LEDs
6 INPUT TYPE DIP
SWITCHES (S1, S2)
14 OUTPUT FAIL-SAFE
SWITCHES
7 BOARD STATUS LEDs
(Code A, Code B, General
Status)
15 ANALOG OUTPUTS (#1
and #2 active for RTU, #3
and #4 inactive)
8 DC POWER OUTPUTS
(3 at +5VDC, 1 at
+12VDC)
16 NETWORK STATUS LEDs
Table 1-1 - MultiFlex RTU

2 • MultiFlex RTU Operator’s Guide 026-1706 Rev 3
2 Mounting and
Powering
The MultiFlex boards are usually mounted by
the refrigeration equipment manufacturer.
Therefore, the installer need only make the
necessary connections between the boards and
the site controller(s).
In some instances, an installer may be required
to mount an I/O board. There are no restrictions
on the location of these boards; however, for
ease of network configuration, it is
recommended that the boards be located
adjacent to the Einstein. I/O boards may be
mounted without an enclosure, but they should
be mounted in a location that is not easily
accessible to avoid tampering or damage.
2.1. Snap-Track Installation
MultiFlex boards not supplied in a custom panel
or other enclosure are supplied with a snap-track
for easy installation. The insulation sheet and
I/O board must be removed from the track
before the track is mounted. The snap-track is
mounted using the 0.1875” mounting slots.
Figure 2-1 shows this installation procedure.
Figure 2-2 provides mounting dimensions for
the MultiFlex board.
Figure 2-1 - MultiFlex Snap-Track Mounting
Figure 2-2 - MultiFlex Board Dimensions

The Plug-In Output Board Mounting and Powering • 3
2.2. The Plug-In Output Board
The MultiFlex RTU has an output sub-board that
plugs to the top of the base board. Typically,
these boards are shipped with the output board
pre-installed on the board using stand-offs, so no
additional hardware setup should be necessary.
The additional board makes the MultiFlex RTU
boards considerably taller than the MultiFlex 16
and other Emerson I/O boards. If you will be
mounting these boards in an enclosure, the board
will need at least 2.5" of clearance between the
base board and the panel door.
2.3. Powering the MultiFlex
RTU Board
All models of MultiFlex require a 24VAC Class
2 input power source. The MultiFlex RTU
requires the power source to be
non-center-tapped.
Emerson supplies a wide variety of 24VAC
transformers with varying sizes and either with
or without center taps. Table 2-1 shows the
transformer sizes and whether they are center-
tapped or non-center-tapped.
Figure 2-3 - Exploded View — MultiFlex RTU
Xformer P/N VA Rating Primary Voltage Center Tap?
640-0041 50 VA 110 VAC No
640-0042 50 VA 220 VAC No
640-0056 56 VA Multi-tap (120/208/240 VAC) Yes
640-0050 75 VA 110 VAC No
640-0045 75 VA 220 VAC No
640-0080 80 VA Multi-tap (120/208/240 VAC) Yes
Table 2-1 - Transformers Compatible with MultiFlex

4 • MultiFlex RTU Operator’s Guide 026-1706 Rev 3
2.3.1. Choosing Transformer Sizes
In most site installations, a single transformer
will power multiple devices. Choose a
transformer with a VA rating large enough to
power all devices that will be attached to it.
Table 2-2 gives the VA ratings of the MultiFlex
RTU in conjunction with other MultiFlex
boards. Refer to your site controller’s manual for
VA ratings of the other I/O boards that may be
powered by one of these transformers.
2.3.2. MultiFlex RTU Power Wiring
The MultiFlex RTU boards do not use a center
tap. Instead, the 0V terminal on the board should
be connected to a separate Earth ground.
Important! The rules that must be followed
when connecting a MultiFlex RTU board to a
transformer are different depending on
whether you have a "new style" MultiFlex
board with an isolated power supply (all
MultiFlex boards shipped after November 1,
2002) or an "old style" MultiFlex board (all
MultiFlex boards shipped before November
1, 2002).
A new-style MultiFlex board has a green power
LED located next to the 24VAC connection
terminal in the upper right corner of the circuit
board (see Figure 2-4 for reference).
If there is a green power LED next to the
connector, your MultiFlex is a new-style
MultiFlex -- refer to Section 2.3.2.1., New-Style
MultiFlex RTU Boards (with Isolated Power
Supply) for power wiring instructions.
If there is no green power LED next to the
connector, your MultiFlex is an old-style
MultiFlex -- refer to Section 2.3.2.2., Old-Style
MultiFlex RTU Boards No Isolated Power
Supply) for power wiring instructions.
2.3.2.1. New-Style MultiFlex RTU Boards
(with Isolated Power Supply)
The new-style MultiFlex board can be connected
to any of the center-tapped transformers
mentioned in Table 2-2, provided the 0V
terminal of the board is connected to an Earth
ground.
Unit VA VAC Center
tapped?
MultiFlex 16 6 24 Yes
MultiFlex 88,
88AO, 168, and
168AO
15 24 NO
MultiFlex RTU 15 24 NO
Table 2-2 - Device Power Requirements
Figure 2-4 - New-Style vs. Old-Style MultiFlex Board
POWER LED
New Style
MultiFlex Board
(Top Left Corner)
NO POWER LED
Old Style
MultiFlex Board
(Top Left Corner)
24 VAC
24 VAC