Multi-Zone Fan Coil Unit Controller | rickardair

Multi-Zone Fan Coil Unit Controller

Rickard’s Fan Coil Unit Multi-Zone Controller is more than a traditional FCU controller. As the name suggests, the controller can now be combined with Rickard’s VAV diffusers so that the FCU can handle multiple zones without the need for pressure sensors or dampers. Since the FCU and diffusers are linked through the tried and tested MLM system, the FCU can regulate the fan speed and hence duct pressure from the diffusers average demand.

The benefits of an FCU Multi-Zone Controller over a traditional FCU supplying constant volume diffusers are: 

  • Zones with different loads can be ducted to the same FCU. Individual temperature control and comfortable occupants at every zone. 
  • Larger FCU’s and more diffusers can be used to reduce cost. 
  • Fan speed matches diffuser demand creating excellent circulation and no dumping at low fan speed. 
  • Never over or under condition different zones again. 
  • To conserve energy, the Fan Coil Unit Multi-Zone Controller can power down the Fan Coil Unit if the room is unoccupied and/or if a window or door is left open.

If desired, the Controller can be used to control the FCU with CAV diffusers. The following applies to a system connected to VAV or CAV diffusers.

Since the Rickard FCU Multi-Zone Controller uses the tried and tested MLM system, commissioning, managing, and integrating your Fan Coil Units with the BMS is easier than ever before.

The Fan Coil Multi-Zone Controller is capable of managing the operation of both two and four-pipe fan coil units, 6-way valves and with or without electric heating. Fan coils with EC fans, 3-speed fans, AC valves, and electric heating can be controlled with the appropriate Fan Coil Multi-Zone Controller model. A built in 220V AC to 12V DC Switch Mode Power Supply (SMPS) removes the need for an external power supply unit or transformer.

Two dry contact inputs are supplied allowing a PIR and/or door or window reed switch to trigger the override. In addition, a loosely regulated 12V supply is available allowing devices such as PIRs to be directly powered from the Fan Coil Multi-Zone Controller.

The Fan Coil Multi-Zone Controller can automatically detect a water supply change-over from hot to cold and vice versa, with the aid of a change-over temperature sensor. This allows two-pipe Fan Coil Units to be operated without the need for electric heating.

The setpoint of the Fan Coil Multi-Zone Controller can be configured externally via Rickards Fan Coil Unit Wall Thermostat or MLM application.

  • Works with VAV diffusers.
      - Matches fan speed to diffuser demand
      - No dumping at low fan speed
      - Control Multiple VAV Zones with one FCU
      - Save by selecting larger FCU’s
      - No over or under conditioning
      - Software wizard aids setup
  • Works with cav diffusers
  • Integrates with MLM & the BMS
  • Two and four-pipe fan coil units
  • With or without electric heating
  • EC & 3 speed fan control
  • 220V AC – 12V DC power supply
  • PIR, door & window switch override
  • Auto water supply temp detection
  • Adjust settings with Rickard stat
  • Free MLM FCU commissioning & management software
 

Rickard MLM FCU ControllerRickard MLM FCU Wallstat

HARDWARE FEATURES

  • Internal 220V AC SMPS.
  • Capable of driving:

                220V, 2kW heating elements directly.
                AC Valves for both heating and cooling.
                3-speed fan.
                EC fan.
                Analogue position-controlled valves.

  • Two dry contact inputs.
  • 12V DC supplementary supply.
ACCESSORIES
  • Rickard Fan Coil Wall Thermostat.

                Toggles Power
                Adjusts Fan Speed
                Sets Temperature
                Shows Room Temperature

PRODUCT SPECIFICATION

Power Supply

  • 220Vac ± 10%, 45Hz-65Hz
  • Power Consumption: 3.3W absolute max (excluding heater, fan and valves)

Environmental

  • Operating Temperature Range: 0 to +50ºC
  • Storage Temperature Range: 0 to +70ºC

Maximum Electrical Ratings 

  • Heater Element: 220V, 2kW
  • 3-Speed Fan: 220V, 3A/contact
  • AC Valves: 220V, 100mA
  • Aux 12V DC supply: 13V ± 1V, 100mA
  • Analogue Controlled EC Fan: 0-10V, 1mA max (10k minimum impedance)
  • Analogue Controlled Valves: 0-10V, 1mA max (10k minimum impedance)
AVAILABLE VARIANTS

Only Variant A (FCU Controller) is currently available.  Simpler versions of variant A will be made available as required.

CONTROL SCHEME

A single Proportional-Integral (PI) control loop controls all the control elements (heater, valves and fan). All analogue outputs are directly mapped to the percentage of control indicated by the control loop, whereas discrete outputs such as the 3-speed fan, AC valves and electric heater operate at predefined control levels meant to approximate the controls output. The below Table indicates the switching points of each discrete control element.

INSTALLATION AND COMMISSIONING

The Fan Coil Multi-Zone Controller can be fitted to a standard MLM 24 installation and can interface with the MLM Tool V8.16 u4 for commissioning and diagnostics. Up to 15 FCU controllers can be connected to each MCU Channel. FCU’s, PCD’s and diffusers should not be mixed on the same channel.

 

Rickard MLM Schematic
FCU_line_drawing

HARDWARE INSTALLATION

The Fan Coil Multi-Zone Controller manages the operation of either a two or four-pipe Fan Coil Unit with, or without electric heating. EC fans, 3-speed fans, AC valves, and electric heating can also be controlled. The Fan Coil Multi-Zone Controller incorporates a 220V AC to 12V DC SMPS removing the need for a separate power supply or transformer.

Two dry contact inputs are supplied allowing a PIR and/or door or window reed switch to override the operation of the Fan Coil Multi-Zone Controller. In addition, a loosely regulated 12V supply is available allowing devices such as PIRs to be directly powered from the Fan Coil Multi-Zone Controller. Please see the User Manual for complete Installation and Commissioning Instructions.

OPERATION CONFIGURATION

There are various operational controls that can be configured by the user. Rickard recommends using the wizard to guide you through the configuration process. These include the minimum and maximum fan speed in heating and cooling, the average diffuser disk position to switch fan speed if using VAV diffusers in your installation, turn-on and turn-off limits for the discretely controlled outputs (AC valves and electric heater), the PI loop control variables, and master command (space-temperature measurement, change-over temperature measurement, and setpoint control.

FANCOIL OPERATING MODES

The Fan Coil Multi-Zone Controller utilises multiple control modes of operation. These modes include:

Heating: In this mode the fan coil is attempting to heat the room/space.

Cooling: In this mode the fan coil is attempting to cool the room/space.

Idle: In this mode the fan coil will not control the room/space temperature or fan speed.

Fan Only: In this mode the fan operates and temperature is not controlled. The fan operates at a fixed speed set by the Wallstat. 

Override: This mode is activated by the door/window input, the occupancy input or by placing the Fan Coil Multi-Zone Controller into manual control.

Test Button: The test button activates a display mode in the MLM Tool Application and does not alter the operation of the Fan Coil Multi-Zone Controller. The Fan Coil Unit can then be identified on the MLM Tool.

FANCOIL CONFIGURATIONS & ORDERING

Secondary: If the FCU is operating as a secondary, only a inter-controller cable is required to link the master (onboard or remote sensing) and secondary FCU controller. Please order a inter-controller cable and specify the required length. Use the MLM tool to zone masters and secondary.

Masters with Onboard Sensing: The FCU has an onboard controller built in. The FCU controller can operate without a wall thermostat provided it is fitted with a correctly placed room temperature sensor. Commissioning of the unit can be done using the MLM tool. Please order a room temperature sensor with the correct length.

2 Pipe Fan Coil Units with hot and cold water supply: In this case it is necessary to sense water pipe temperature when the supply temperature changes. Please order the correct length change over sensor. Our standard length is 0.5m.

Master with Remote Sensing: Please order a Rickard FCU Wall Thermostat. 8m RJ45 cable included. 

BACnet BMS: An MCU and cabling is required. Each FCU controllers requires a 3 core inter-controller cable connection. One RJ9 cable connects one of up to 15 FCU controllers to 1 of 4 MCU channels. Please order an RJ9 cable/channel </= 150m.

FCU and VAV diffuser multi-zone control: Only one FCU can be connected per channel/PSU. A 3-pin mini-fit connector connects the FCU via a 3-core cable to the diffuser network with a 4-pin mini-fit connector. Please contact Rickard to order this cable.

FCU and VAV diffuser multi-zone control without BMS: The FCU need not be zoned and a maximum of 15 diffusers can be connected per FCU. Up to 15 diffuser zones can be connected per channel.

FCU and VAV diffuser multi-zone control with BMS: The FCU must be zoned and a maximum of 14 diffusers can be connected per FCU. Up to 14 diffuser zones can be connected per channel.

The Fan Coil Wallstat can alter the operational mode of the Fan Coil Multi-Zone Controller, adjust the fan speed, set the setpoint, display the space-temperature and cause the Fan Coil Multi-Zone Controller to power off.

The Fan Coil Wallstat utilises four user control buttons, these being, power, display cycle, increment and decrement. 

FAN COIL WALLSTAT MODES

  • Off:
  • Automatic Control: Control of valves, heater and fan in order to reach the setpoint temperature.
  • Manual Fan Only Control: Temperature control is turned off and the fan speed can be set to low, medium or high.

Rickard MLM FCU Wallstat

 DISPLAY


The Fan Coil Wallstat can indicate three possible displays.
 
1.  Room Temperature
  • A bracketed thermometer indicates temperature display. The room temperature value is displayed.

2.  Fan Speed Control

  • A bracketed fan shows fan speed adjustment.
  • A value of 1-3 or A for Automatic and a corresponding bar graph indicates the fan speed.
3.  Set Point Display
  • The abbreviation SP indicates setpoint adjustment. The setpoint value is displayed.

Rickard MLM FCU Wallstats

FCU’S & CAV DIFFUSERS

Up to 15 FCU controllers can be connected to each MCU Channel, iPSU/PSU. 

Secondary FCU’s: If the FCU is operating as a secondary unit, only an inter-controller cable is required to link the master (onboard or remote sensing) and secondary FCU controller. Please order an inter-controller cable and specify the required length. Use the MLM tool to zone master & secondary FCU’s.

Master FCU’s with Onboard Sensing: The FCU has an onboard controller built in. The FCU controller can operate without a wall thermostat provided it is fitted with a correctly placed room temperature sensor. Commissioning of the unit can be done using the MLM tool. Please order a room temperature sensor with the correct length. 

2 Pipe Fan Coil Units with hot and cold water supply: In this case it is necessary to sense water pipe temperature when the supply temperature changes. Please order the correct length change over sensor. Our standard length is 0.5m. 

FCU with Remote Sensing: Please order a Rickard FCU Wall Thermostat. 8m RJ45 cable included. 

BACnet BMS: An MCU and cabling is required. Each FCU controller requires a 3 core inter-controller cable connection. One RJ9 cable connects one of up to 15 FCU controllers to 1 of 4 MCU channels. Please order an RJ9 cable/channel </= 150m.

FCU’S & VAV DIFFUSERS

Only one FCU can be connected per MCU channel, iPSU/PSU. An adapter cable that connects the FCU to the diffuser network is required to connect the two types of hardware. A 3-pin mini-fit connector connects the FCU via a 3-core cable to the diffuser network with a 4-pin mini-fit connector.

FCU and VAV diffuser multi-zone control without BMS: A maximum of 15 diffusers can be connected per FCU. Up to 15 diffuser zones can be connected per channel. The FCU need not be zoned through the MLM software interface.

FCU and VAV diffuser multi-zone control with BMS: The FCU must be zoned and a maximum of 14 diffusers can be connected per FCU. Up to 14 diffuser zones can be connected per channel.

The standard Rickard  Multi-ZoneFan Coil Unit Controller is supplied without a power cable, inter-controller cable, wallstat or sensors. This is because the installation options are so varied. Please consider your installation, this document or consult a sales representative for more detail.

OPTIONS
  • Power cable and plug top: Please specify cable length and plug type. Please see “Electric Plug Ordering Guide” for plug top ordering information.
  • Inter-controller cables: Our standard length is 8m. Please specify special lengths.
  • FCU to Diffuser Adapter Cable: An adapter cable that connects the FCU to the diffuser network is required to connect the two types of hardware. A 3-pin mini-fit connector connects the FCU via a 3-core cable to the diffuser network with a 4-pin mini-fit connector.
ACCESSORIES
  • Fan Coil Wallstat: One wallstat is required per controller.
  • Master Communications Unit (MCU): 15 FCU &/ VAV Diffusers can connect to 1 MCU channel. An MCU has 4 channels. The MCU acts as a gateway to the BMS. 
  • Intelligent Power Supply Unit (iPSU): 15 FCU &/ VAV Diffusers can connect to 1 iPSU. An iPSU has 1 channel. The I PSU powers the VAV diffusers and acts as a gateway to the BMS. 
  • Temperature sensors: For room sensing, change over/supply air sensing and intermediate temperature sensing.