Emerson E2 MultiFlex CUB Board, Losing Contact With Zone Applications, Stand-Alone MultiFlex RTUs

11.7.13Losing Contact With Zone Applications

When a MultiFlex RTU or AHU loses contact with the Zone application to which it was assigned, it is forced to operate in Stand-Alone Mode. Each of the different appli- cations have different stand-alone capabilities.

11.7.14 Stand-Alone MultiFlex RTUs

The MultiFlex RTU uses its own occupied and unoccu- pied heating and cooling setpoints when it operates in Stand-Alone Mode. These values are programmed through the MultiFlex RTU application and stored in the memory on the MultiFlex RTU board itself. During Stand-Alone Mode, the MultiFlex RTU uses its space temperature sen- sor value as the control input.

The MultiFlex RTU also has a seven-day fallback occupancy schedule that it may use to determine occupied or unoccupied building status. Different times may be pro- grammed in the MultiFlex RTU application for Sunday through Saturday. Holiday scheduling is not supported.

Economization control is available if the sensor pro- viding the economization checking is connected to an input on the MultiFlex RTU. Otherwise, economization is disabled.

As it does in Temperature Control, the MultiFlex RTU stores its own occupied and unoccupied dehumidification setpoints. If the MultiFlex RTU has its own humidity sen- sor, it will continue dehumidification using the stored fall- back setpoints.

11.7.15MultiFlex RTU/ARTC and AHU Zone Association

MultiFlex RTUs and AHUs are assigned to Zone appli- cations using the Zone Association screen. To access this screen:

1.Press  for the Main Menu.

2.Press for System Configuration.

3.Press  the Network Setup menu.

4.Press  for Associations.

Figure 11-18- Zone Association Screen (BX-400 Unit Shown)

The Zone Association screen lists all RTUs/ARTCs, and AHUs that are set up on the current E2. To make an association, move the cursor to the HVAC Zone field of the RTU/ARTC or AHU you wish to associate, and press

(LOOK UP) to open the Application Selection menu and use the arrow keys to scroll to find the desired Zone name. When this menu is open, use  and  to move quickly to the beginning or end of the list respec- tively.

From this screen, you may also choose to jump to the Setup screen to configure an individual RTU/ARTC, AHU or Zone application by using the  (SETUP AHU) key or the  (SETUP ZONE) key.

11.8 MultiFlex CUB Board

The MultiFlex Condensing Unit Board (CUB) is a “smart” input/output board designed to control single con- densing units. A single condensing unit is a self-contained compressor and condenser bearing unit which controls refrigeration in a single case line-up or walk-in cooler.

The MultiFlex CUB uses the same general hardware configuration as a MultiFlex 168AO. It is equipped with a processor and extra memory to allow it to control com- pressors, condensers, refrigeration, and defrost for a single condensing unit using on-board I/O and control algo- rithms.

The MultiFlex CUB has its own installation and opera- tion manual, (P/N 026-1706).

11-30 • E2 RX/BX/CX I&O Manual 026-1614 Rev 4 5-JAN-2013