User's Manual

EXCEL 10 FCU CONTROLLER LNS PLUG-INS USER GUIDE

EN2B-0285GE51 R0909

Window Sensor

The digital input for reading input from a window contact

provides the Excel 10 FCU Controller with a means to disable

its temperature control activities if someone has opened a

window or door in the room. If no window sensor is directly

connected to the Excel 10 FCU Controller, the sensor from

another node may be used by binding it to nviWindow. Frost

protection remains active. Normal temperature control

resumes when the window closes.

Demand Limit Control

When a high-electrical-demand signal is received from an

energy management system via the L

ONWORKS network

(nviDlcShed), the Excel 10 FCU Controller uses Demand

Limit Control Bump to shift the current setpoint (down for

heating and up for cooling) by the configured value to save

energy.

Fig. 4. Optimum start - heating

Optimum Start Gradients

There are two parameters, Cool Rec Ramp and Heat Rec

Ramp, which can be configured to cause the cooling and

heating setpoints respectively to ramp up to their occupied

settings from their unoccupied or standby settings prior to

scheduled occupancy. The Excel 10 FCU Controller uses the

configured rates to determine the optimum time to start

increasing the heating or cooling demand. See the following

figures. The configuration parameters are in K/hour.

Fig. 5. Optimum start - cooling

Occupancy Status

The occupancy status is determined based upon the following table. Manual override may come from nviManOccCmd or from

the bypass push-button.

Table 3. Effective occupancy mode arbitration

scheduled occupancy mode occupancy sensor status manual override status effective operating mode

"occupied" room occupied not assigned OC_OCCUPIED

"occupied" room not occupied not assigned OC_STANDBY

X X "occupied" OC_OCCUPIED

X X "unoccupied" OC_UNOCCUPIED

X X "standby" OC_STANDBY

"occupied" X "standby" OC_OCCUPIED

"standby" X not assigned OC_STANDBY

"standby" X "standby" OC_OCCUPIED

"unoccupied" X not assigned OC_UNOCCUPIED

"unoccupied" X "standby" OC_BYPASS

X=Don't care