41
the ERM wheel is off
2.
Recovery mode in heating: Economizer is opened at the
minimum position and the space temperature is higher than
the outside temperature. The ERM wheel is on.
3.
Recovery mode in cooling: The economizer opened at the
minimum position and the space temperature is lower than
the outside temperature. The ERM wheelis on.
4.
The unit is in free-cooling mode, the economizer is opened,
the space temperature is higher than the outside
temperature. The ERM wheel is off.
6.27
– Thermodynamic energy recovery (THR)
The ERM energy recovery wheel is replaced by a refrigeration
circuit in the THR.
THR is considered as additional refrigeration circuit with
equal role as regular refrigeration citcuit(s). THR’s ON/OFF
is requested by capacity control logic and compressor load/
unload sequence. It is possible to be used as lead or lag
refrigeration source depend on user configured minimum
fresh air.
THR is always used with return fan option. When THR is
ON, supply air flow rate shall be minimum 80% nominal air
flow rate, economizer damper shall modulate to guatantee
safe function of THR.
6.28
– Demand limit
The demand limit is used to restrict the unit power consumption.
The SmartVu control system allows
limitation of the unit capacity, using user-controlled
volt-free contacts.
The unit capacity can never exceed the limit setpoint
activated by these contacts. The limit setpoints can be
modified in the GENCONF menu.
6.29 - VAV option
When this option is equipped, the indoor fan airflow can be
managed in three ways:
•
Constant air volume: Allows to provide a constant airflow in
the product lifetime
•
Variable air volume 1: Variable airflow in cooling only mode
to fit the ventilation needs as a function of circuit
•
Variable air volume 2: Variable airflow for both cooling and
heating modes.
The three modes use PID logic to maintain the required airflow.
When coupled to the economizer option, the fresh air rate is
maintained automatically.
The system has to be calibrated by Carrier Service
6.30
– Return fan option
In some applications with high return duct ESP, a return fan
may be applied to help maintain the air flow rate and the
building pressure. Return fan’s ON/OFF is in same status with
the supply fan and the return fan’s speed is command.
However, any faults active when the supply is interrupted are
saved and may in certain cases prevent a circuit or a unit from
restarting.
A manual reset must be run from the touch screen interface or the
web via the Reset alarms menu, item RST_ALM. Alarm reset can
be protected by a basic user level password.
6.31
– Night mode
Night mode allows users to configure the unit to operate with
specific parameters in a specific time period. During the night
period, the fan runs atlow speed, if permitted by the current
operating conditions.In addition, the user can reduce the unit
capacity.
The night period is defined by a start time and an end time that
are the same for each day of the week. The Night mode
settings can be configured via the Configuration menu
(GEN_CONF
– General Configuration). Only logged-in users
can modify the night mode settings.
To set the night mode
1. Navigate to the Configuration menu (logged-in users only).
2. Select
General Configuration
(GEN_CONF).
3. Set parameters corresponding to the night mode.
Night Mode Start Hour [nh_start]
00:00 to 24:00
Night Mode End Hour [nh_end]
00:00 to 24:00
6.32 Refrigerant leak detection option
When the normally closed refrigerant leak detection contact is
open,
the unit is shut down.
6.33 BACnet
The BACnet/IP communication protocol is used by BMS or the
programmable controllers to communicate with the control.
This protocol is available as a
standard
To enable/disable BACnet communication option
1.
Go to the Main menu.
2.
Navigate to the Configuration menu, and then the
Network menu.
3.
Select the BACnet Parameters menu (BACNET).
4.
Set the "BACnet Enable" parameter to "enable".
6.34 Modbus
The modbus protocol is used for communication with the
building management( BMS )or the programmable controllers
,which is acting as the master, while the multiple units are
watched as slaves. This protocol is available as a
standard
To enable/disable MODBUS communication option
1.
Go to the Main menu.
2.
Navigate to the Configuration menu, and then the
Network menu.
3.
Select the MODBUSParameters menu (MODBUS).
4.
Set the "MODBUS Enable" parameter to "enable".
6.35- Schedule setting
The control incorporates two time schedules, where the first one
(OCCPC01S) is used for controlling the unit start/stop, whereas
the second one (OCCPC02S) is used for controlling the dual
setpoint.
