LIBRA Pressure Independent Control Valves

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MVE504S         172,00 €

MVE504S-65 with  IP65         202,00 €

MVE504SR with electronic failsafe function         256,00 €

MVE504SR-65 with IP65 and  electronic failsafe function         286,00 €

Prices are subject to VAT 24%

Actuator for globe valve, 400 N, 24 Vac / Vdc, IP54 or IP65 (-65 models).
U-bolt connection with short yoke.
Stroke from 5 to 30 mm.
Command : 3 point and 0..10 Vdc selectable.
Working fields 0 ÷ 10 Vdc, 2 ÷ 10 Vdc, 0 ÷ 5 Vdc, 5 ÷ 10 Vdc, 2 ÷ 6 Vdc, 6 ÷ 10 Vdc, 4 ÷ 20 mA.
Plug & Play and self-calibration in case of variations during operation. 

MVE504S-2-RS         345,00 €,

MVE504SR-2-RS  with electronic failsafe function         429,00 €

Prices are subject to VAT 24%

Multiprotocol Network actuator for PICV and Globe Valves with energy and temperature control functions, BACnet and Modbus protocols.

Force – 400 N
Control signal – Modbus, BACnet or proportional
Power supply – 24 V AC/DC
Connection type - U-bolt
Stroke – 5-30 mm

Emergency Return – electronic fail-safe function (MVE504SR-2-RS)

MVE5xxx-2-RS is equipped with two temperature inputs for direct connection of NTC 10K temperature sensor to allow:

• Temperature monitoring 

• DeltaT and Temperature – control and limit

• Energy Calculation with Libra PICV (VLX6P or VLX8P) 

Position Control

The actuator receive modulating signal coming from a control loop implemented by BMS and the valve is positioned from 0% to 100% accordingly to the voltage (0...10 V DC) or the current (4...20 mA) or RS485 (Modbus RTU or BACnet MS/TP) Command. When it is installed with PICV (iC PICV or custom) the control signal represents the desired flow rate that is a % from 0% to 100% of the maximum flow rate. Actuator position characteristic is normally linear, but MVE5xxx-2-RS allow to set an equal percentage behaviour allowing to make a linear valve working like an equal percentage valve.

Diagnostics

The actuator is equipped with a self-diagnostic algorithm able to detect the following conditions\anomalies:

• Actuator status (Normal Operation, Calibration, Initialization, Fault, Manual).

• Calibration on a stroke out of range 5-60 mm.

• Unexpected stall (e.g. valve blocked or extra stroke due to actuator not correctly coupled); the number of detected events is stored permanently.

• Supply voltage outside the allowed range; the number of detected events is stored permanently.

• Total number of opening and closing cycles.

• Temperature sensors outside the allowed temperature range (if any).

Temperature control loop

MVE5xxx-2-RS can be connected to 2 sensors for measuring the supply and return temperature of a hydraulic circuit for monitoring purposes or for control purposes. The actuator can implement a temperature control loop (PID): the actuator independently controls the supply or the return temperature or the ∆T according to a set-point provided by the BMS -  the BMS only sets the temperature\ΔT setpoint and the actuator works independently even in the absence of the RS485 connection. If only temperatures monitoring is required, the measured values are made available to the BMS through dedicated Modbus RTU or BACnet MS/TP registers. Temperature setpoints, PID control parameters, Heating/Cooling mode can set via Modbus RTU or BACnet MS/TP or via USB by the MVE-2-RS Configurator.

ΔT limit function

If a heating or cooling system works with a differential temperature between the supply and return too low, it means that there is no heat exchange between the fluid and the air flow and therefore it is more efficient to reduce the fluid flow as this does not generate any heating or cooling effect. This means that the pumps circulate too much water with unnecessary increase of energy consumption. The ΔT limit function automatically limits the flow rate to prevent the ΔT level from falling below the desired differential temperature.

This function overrides the control signal from the BMS when the ΔT is lower than the setpoint; BMS will be again in charge of the valve positioning when the ΔT is higher than the setpoint. The minimum value of ΔT and the other parameters of the control loop (PID) can set via Modbus RTU or BACnet MS/TP or via USB.

Supply/Return temperature limit function

MVE5xxx-2-RS can implement a limit control loop on the return or on the supply temperarature in order to override the BMS control when energy efficiency conditions are not respected (e.g. in cooling mode return temperature higher than a setpoint value). The following limiting functions can be implemented:

• Maximum temperature limit control loop: the actuator will override the BMS control signal when the supply \return temperature is higher than the setpoint; the user can select if the loop has to be implemented on the supply or return temperature sensor. For example in a domestic hot water application the actuator can override the bms control signal if the supply temperature exceeded a setpoint value that could be dangerous for the user.

• Minimum temperature limit control loop: the actuator will override the BMS control signal when the supply \return temperature is lower than the setpoint; the user can select if the loop has to be implemented on the supply or return temperature sensor. For example in a cooling application the actuator can override the BMS control signal if the return temperature is lower than a setpoint value in order not to affect the chiller efficiency.

Power Control Function

When the actuator is installed with PICV valves (iC or custom) and both temperature sensors are installed, the Power Control function can be enabled and the MVE-2-RS calculates the thermal power transferred from the coil and to control it independently of pressure fluctuations in the systems and other external conditions that could affect the heat transfer process, lowering the overall efficiency. It is possible to set the maximum desired power (Design power Pmax) whose value is between zero and the nominal power values (Pnom) defined for the valve at the various ΔT 

Power limit function

 When the actuator is installed on PICV valves (iC or custom) and both temperature sensors are installed, the Power Limit function can be enabled and the MVE-2-RS limits the actuator position when the BMS command is greather than of Set Max Power Limit value (Set Power Limit Set point). 

Calibration function

MVE5xxx-2-RS is equipped with an automatic calibration function. The plug & play function enables the calibration at the first start-up of the actuator and therefore no further calibration operations are required unless maintenance is required on the valve or particular alarm conditions occur. If it is necessary to repeat the calibration, it can be activated by pushing the S2 button on the electronic board or remotely via Modbus RTU or BACnet MS/TP.