Fan coil supply temperature cascade control cooling (FcuTCasCtlC11)

Overview

The application function "Fan coil unit temperature cascade control for cooling 11" (FcuTCasCtlC11) is the hub for the sequencing of the room temperature controllers for FCU cooling. It determines the room cooling setpoint and the room cooling demand signals to maintain the room temperature at the cooling setpoint.

For the cooling coils and an outdoor air damper (if present), the room demand output signal is designed for cascaded supply temperature control in the room segment. (air sensor(s) required)

The following devices in the room segment(s) are supported:

Cooling coil
OA damper
Floor cooling
Heating/Chilled ceiling (panels or beams)
Heating/Cooling coil
Fan

Function

This AF works in collaboration with a room segment HVAC device component cooling AF. The cooling room temperature PID controller is enabled based on a signal that is read via the grouping function (from equipment in the room segment) indicating whether cooling is available.

Devices for cooling are activated in the following order (default):
Floor cooling > Chilled ceiling > Coil & OA damper > Fan

Cooling setpoint and plant mode

	Plant operation mode	Cooling setpoint
1	Off	Protection cooling
2	Protection	Protection cooling
3	Economy	Economy cooling
4	Pre-Comfort	Pre-Comfort cooling
5	Comfort	Comfort cooling
6	Warm-up	Protection cooling
7	Cool down	Comfort / Pre-Comfort cooling¹
8	Room low temperature protection	Protection cooling
9	Condensation overflow protection	n/a
10	Free cooling	Comfort cooling
11	Night cooling	Comfort cooling
12	Ventilation	Comfort cooling
13	Equipment temperature protection	n/a
14	Air volume flow off	Protection cooling
15	Not used
16	Not used
17	Not used

¹⁾ Depends on Next room operating mode (NxROpMod) in HvacPltMod AF.

Feature configuration

Feature selections for "Room HVAC coordination" are accessed via the Application configuration task in the Configuration component.

Feature (AF)	Feature description	Ref.
Trend for present cooling setpoint	None/Active	☑

Configuration

Objects

Description	Object	Type	Default value
Cooling setpoint for comfort ▶ Default command must be configured on priority level 17. 0...50 [°C], 32.0...122.0 [°F]	SpCCmf	APrcVal	24 [°C] 75.0 [°F]
Delta cooling setpoint for pre-comfort ▶ Delta between comfort and pre-comfort setpoints. 0...10 [K], 0.0...18.0 [°F]	DSpCPcf	ACnfVal	1 [K] 2.0 [°F]
Cooling setpoint for economy 0...50 [°C], 32.0...122.0 [°F]	SpCEco	ACnfVal	35 [°C] 85.0 [°F]
Cooling setpoint for protection 0...50 [°C], 32.0...122.0 [°F]	SpCPrt	ACnfVal	40 [°C] 104.0 [°F]

Parameters

Description	Parameter	Default value
Offset for fan start ▶ Fan speed control gets a higher setpoint.	OfsFanStt	0 [K] 0.0 [°F]
Comfort configuration 1:None ▶ None, means no aggregate is activated depending on cooling demand. 2:Radiant devices ▶ Radiant device, means only radiant devices (e.g. Chilled ceiling) will be activated depending on cooling demand. 3:Air treatment devices ▶ Air treatment devices, means only air treatment devices (Cooling coil, Fan) will be activated depending on cooling demand. 4:Radiant & air treatment devices ▶ Radiant & air treatment devices, both will be activated depending on cooling demand.	CmfCnf	4:Radiant & air treatment devices
Pre-Comfort configuration Enumeration see CmfCnf	PcfCnf	4:Radiant & air treatment devices
Economy configuration Enumeration see CmfCnf	EcoCnf	4:Radiant & air treatment devices
Protection configuration Enumeration see CmfCnf	PrtCnf	4:Radiant & air treatment devices
Cool down configuration Enumeration see CmfCnf	CoolDnCnf	4:Radiant & air treatment devices
Free cooling configuration Enumeration see CmfCnf	FreeCCnf	4:Radiant & air treatment devices
Coil: Controller mode by comfort 0:Continuous 1:2-position ▶ 2-position, the output will be 0 or 100 % nothing between, be aware of delays.	CoilCmf	0:Continuous
Coil: Controller mode by pre-comfort Enumeration see CoilCmf	CoilPcf	0:Continuous
Coil: Controller mode by economy Enumeration see CoilCmf	CoilEco	0:Continuous
Coil: Controller mode by protection Enumeration see CoilCmf	CoilPrt	0:Continuous
Coil: Controller mode by cool down Enumeration see CoilCmf	CoilCoolDn	0:Continuous
Radiant devices: Controller mode by comfort Enumeration see CoilCmf	RadDevCmf	0:Continuous
Radiant devices: Controller mode by pre-comfort Enumeration see CoilCmf	RadDevPcf	0:Continuous
Radiant devices: Controller mode by economy Enumeration see CoilCmf	RadDevEco	0:Continuous
Radiant devices: Controller mode by protection Enumeration see CoilCmf	RadDevPrt	0:Continuous
Radiant devices: Controller mode by cool down Enumeration see CoilCmf	RadDevCoolDn	0:Continuous
Radiant floor cooling sequence	RfrCSeq	1 [1..8 unique]
Radiant ceiling cooling sequence	RcgCSeq	2 [1..8 unique]
Coil cooling sequence	CoilCSeq	3 [1..8 unique]
Fan cooling sequence	FanCSeq	4 [1..8 unique]
Temperature difference unit ▶ Defined by selected engineering unit – do not change.	TDiffUnit	[K] [°F]

Interface

Interface	Description	Type	Ref.	Owned by
PrSpC	Present cooling setpoint	APrcVal	●	-
TrndPrSpC	Trend for present cooling setpoint	FtrSel	☑	-
PrSpCCmf	Present cooling setpoint for comfort	ACalcVal	●	-
PrSpCPcf	Present cooling setpoint for pre-comfort	ACalcVal	●	-
PrSpCEco	Present cooling setpoint for economy	ACalcVal	●	-
PrSpCPrt	Present cooling setpoint for protection	ACalcVal	●	-
FanTRCtrC	Room temperature controller cooling for fan	Controller	●	-
CoilTRCtrC	Room temperature controller cooling for coil	Controller	●	-
RcgTRCtrC	Room temperature controller cooling for radiant ceiling	Controller	●	-
RfrTRCtrC	Room temperature controller cooling for radiant floor	Controller	●	-
RCtl	Room control	GrpMaster	◉	Room
SpCCmf	Cooling setpoint for comfort	APrcVal	●	-
DSpCPcf	Delta cooling setpoint for pre-comfort	ACnfVal	●	-
SpCEco	Cooling setpoint for economy	ACnfVal	●	-
SpCPrt	Cooling setpoint for protection	ACnfVal	●	-

Engineering and commissioning

Radiant floor is likely to change room temperature slower than other HVAC equipment. For specific projects, it may be useful to slow down the action of the relevant room temperature controller (continuous, PID) or change the controller mode to 2-position.