Functional description

VAV terminal units control the volume flow in a closed loop, i.e. measurement – comparison – control.

The volume flow rate is determined by measuring the differential pressure (effective pressure). For this purpose the VAV terminal unit is fitted with a differential pressure sensor.

The static differential pressure transducer transforms the effective pressure into a voltage signal. The volume flow rate actual value is hence available as a voltage signal. The factory setting is such that 10 V DC always corresponds to the nominal volume flow rate (V_nom).

The volume flow rate setpoint value comes from a higher-level controller (e.g. room temperature controller, air quality controller, central BMS) or from switch contacts. Variable volume flow control results in a value between V_min and V_max. It is possible to override the room temperature control, e.g. by a complete shut-off of the duct.

The controller compares the volume flow rate setpoint value to the actual value and controls the actuator accordingly if there is a difference.

The volume flow rate parameters V_min and V_max are set on potentiometers (VRP) or stored in the controller. Voltage ranges are factory stored in the controller. Changes on the customer's site can easily be carried out using a potentiometer, an adjustment device or a notebook with service tool.

Volume flow control

• The volume flow controller works independent of the duct pressure
• Differential pressure fluctuations do not result in permanent volume flow rate changes
• To prevent the control from becoming unstable, a dead band is allowed within which the damper blade does not move.
• The factory set volume flow rate parameters can be altered by the customer

Application

• Electronic volume flow controller VRP-M, combined with a static differential pressure transducer VFP-300, as Universal controller
• Variable air or constant air volume flow control
• The flow rate is measured using the static measurement principle
• Voltage range for the actual and setpoint value signals 0 – 10 V DC or 2 – 10 V DC
• Separate inputs for override controls enable the centralised switching of groups of controllers
• With MP bus interface: Up to eight users, such as VRP-M, can be addressed on an MP bus (LAN). This allows for the integration with higher-level systems. DDC controller with MP bus interface to control the Universal controller. Belimo interface UK24LON for LonWorks systems; UK24EIB for EIB systems; UK24MOD for Modbus systems; UK24BAC for BACnet
• When the MP bus interface is used, the analog 0 – 10 V or 2 – 10 V interface cannot be used at the same time.
• The MP bus interface cannot be used with fast-running actuators

Construction

Volume flow controller VRP-M with static differential pressure transducer VFP-300

• BP3: Actuator NM24A-V-ST for TVR, TVJ, TZ-Silenzio, TA-Silenzio TVZ, TVA, TVLK
• BP1: Actuator SM24A-V-ST for TVT
• BPB: Spring return actuator NF24A-V-ST for TVR, TVJ, TVT, TZ-Silenzio, TA-Silenzio TVZ, TVA, TVRK
• BPG: Fast-running actuator LMQ24A-SRV-ST for TVR, TVZ, TVA, TVRK up to nominal size 250, and TVLK or NMQ24A-SRV-ST for TVR, TVZ, TVA, TVRK from nominal size 315 and TVJ, TVT, TZ-Silenzio, TA-Silenzio

Signal voltage ranges

• 0: 0 – 10 V DC
• 2: 2 – 10 V DC with shut-off function (< 0.1 V DC)

Operating modes

E: Single and M: Master

• V_min: Minimum volume flow rate
• V_max: Maximum volume flow rate

S: Slave operation

• V_min: 0 %
• V_max: Volume flow rate ratio to the master controller

F: Constant value

• V_min: constant volume flow rate
• V_max: 100 %

Parameters are factory set. The customer defines the required operating mode and the volume flow rates in the order code at the time of ordering.

Commissioning

• On-site adjusting is not required
• When installing the VAV terminal units it is important to assign each room the correct unit based on the ordered volume flow rates
• After successful installation and wiring the controller is ready for use
• Carry out zero point correction for the controller and adapt the actuator.
• The volume flow rate parameters V_min and V_max can be adjusted at a later stage using an adjustment device

Volume flow and differential pressure controller VRP-M

Static differential pressure transducer VFP-300

Actuators NM24A-V and NM24A-V-ST

Actuators SM24A-V and SM24A-V-ST

Spring return actuators NF24A-V and NF24A-V-ST

Fast-running actuator LMQ24A-SRV-ST

Fast-running actuator NMQ24A-SRV-ST

Application

• Electronic volume flow controller VRP, combined with a static differential pressure transducer VFP-300, as Universal controller
• Variable air or constant air volume flow control
• The flow rate is measured using the static measurement principle
• Voltage range for the actual and setpoint value signals 2 – 10 V DC
• Separate inputs for override controls enable the centralised switching of groups of controllers

Construction

Volume flow controller VRP with static differential pressure transducer VFP-300

• BB3: Actuator NM24A-V-ST for TVR, TVJ, TZ-Silenzio, TA-Silenzio, TVZ, TVA, TVRK, TVLK
• BB1: Actuator SM24A-V-ST for TVT
• BBB: Spring return actuator NF24A-V-ST for TVR, TVJ, TVT, TZ-Silenzio, TA-Silenzio, TVZ, TVA, TVRK

Signal voltage range

• 2: 2 – 10 V DC

Operating modes

E2: Single and M2: Master

• V_min: Minimum volume flow rate
• V_max: Maximum volume flow rate

S2: Slave operation

• V_min: 0 %
• V_max: Volume flow rate ratio to the master controller

F2: Constant value

• V_min: constant volume flow rate
• V_max: 100 %

Parameters are factory set. The customer defines the required operating mode and the volume flow rates in the order code at the time of ordering.

Commissioning

• On-site adjusting is not required
• When installing the VAV terminal units it is important to assign each room the correct unit based on the ordered volume flow rates
• After successful installation and wiring the controller is ready for use
• Carry out zero point correction for the controller and adapt the actuator.
• The volume flow rate parameters V_min and V_max can be adjusted at a later stage using potentiometers

Volume flow controller VRP

Static differential pressure transducer VFP-300

Actuators NM24A-V and NM24A-V-ST

Actuators SM24A-V and SM24A-V-ST

Spring return actuators NF24A-V and NF24A-V-ST

Application

• Electronic volume flow controller GUAC-S3 as Universal controller with integral differential pressure transducer
• Variable air or constant air volume flow control
• The flow rate is measured using the static measurement principle
• Voltage range for the actual and setpoint value signals 0 – 10 V DC or 2 – 10 V DC

Construction

Volume flow controller GUAC-S3

• XD1: Actuator 227-024-08-V for TVR, TVJ, TVT, TZ-Silenzio, TA-Silenzio, TVZ, TVA, TVRK
• XD3: Spring return actuator 361C-024-20-V/ST07 for TVR, TVJ, TVT, TZ-Silenzio, TA-Silenzio, TVZ, TVA, TVRK

Signal voltage ranges

• 0: 0 – 10 V DC
• 2: 2 – 10 V DC with shut-off function (< 0.8 V DC)

Operating modes

E: Single and M: Master

• V_min: Minimum volume flow rate
• V_max: Maximum volume flow rate

S: Slave operation

• V_min: 0 %
• V_max: Volume flow rate ratio to the master controller

F: Constant value

• V_min: constant volume flow rate
• V_max: 100 %

Parameters are factory set. The customer defines the required operating mode and the volume flow rates in the order code at the time of ordering.

Commissioning

• On-site adjusting is not required
• When installing the VAV terminal units it is important to assign each room the correct unit based on the ordered volume flow rates
• After successful installation and wiring the controller is ready for use
• Carry out zero point correction for the controller using adjustment device AT-VAV-G
• The volume flow rate parameters V_min and V_max can be adjusted at a later stage using an adjustment device

Volume flow controller GUAC-S3

Actuator 227-024-08-V

Spring return actuator 361C-024-20-V

Functional description

The static differental pressure transducer transforms the differential pressure into a voltage signal. The differential pressure actual value is available as a voltage signal. The factory setting is such that 10 V DC always corresponds to the nominal differential pressure (Δp_nom).

The differential pressure setpoint value is either a constant value or it comes from a setpoint adjuster or from switch contacts.

The controller compares the differential pressure setpoint value to the actual value and controls the actuator accordingly.

The differential pressure parameters are set on a potentiometer (VRP-STP) or stored in the controller. Voltage ranges are factory stored in the controller. Changes on the customer's site can easily be carried out using a potentiometer, an adjustment device or a notebook with service tool.

Constant pressure control

• The differential pressure controller works independent of the duct pressure
• Pressure fluctuations do not result in permanent differential pressure changes
• To prevent the control from becoming unstable, a dead band is allowed within which the damper blade does not move.
• The factory set differential pressure parameters can be altered by the customer

Variable pressure control

• Relays or switch contacts connected to the control signal input Y/Z can be used to achieve constant pressures ∆p_min and ∆p_max or to override various control settings.

Application

• Electronic differential pressure controller VRP-M, combined with a static differential pressure transducer VFP-100 or VFP-600, as Universal controller
• Variable or constant differential pressure control
• The differential pressure is measured using the static measurement principle
• Voltage range for the actual and setpoint value signals 0 – 10 V DC or 2 – 10 V DC
• Separate inputs for override controls enable the centralised switching of groups of controllers
• With MP bus interface: Up to eight VRP-M users can be addressed on an MP bus (LAN); Belimo-Interface UK24LON for LonWorks systems; UK24EIB for EIB systems; UK24MOD for Modbus systems; UK24BAC for BACnet; DDC controllers with MP bus interface can control the Universal controller via data transfer
• When the MP bus interface is used, the analog 0 – 10 V or 2 – 10 V interface cannot be used at the same time.
• The MP bus interface cannot be used with fast-running actuators

Construction

Differential pressure controller VRP-M with static differential pressure transducer VFP-100

• BR3: Actuator NM24A-V-ST for TVR, TVJ, TZ-Silenzio, TA-Silenzio, TVZ, TVA, TVRK
• BR1: Actuator SM24A-V-ST for TVT
• BRB: Spring return actuator NF24A-V-ST for TVR, TVJ, TVT, TZ-Silenzio, TA-Silenzio, TVZ, TVA, TVRK
• BRG: Fast-running actuator LMQ24A-SRV-ST for TVR, TVZ, TVA, TVRK up to nominal size 250, and TVLK or NMQ24A-SRV-ST for TVR, TVZ, TVA, TVRK from nominal size 315

Volume flow controller VRP-M with static differential pressure transducer VFP-600

• BS3: Actuator NM24A-V-ST for TVR, TVJ, TVRK
• BS1: Actuator SM24A-V-ST for TVT
• BSB: Spring return actuator NF24A-V-ST for TVR, TVJ, TVT, TVRK
• BSG: Fast-running actuator LMQ24A-SRV-ST for TVR, TVRK up to nominal size 250, or NMQ24A-SRV-ST for TVJ, TVT and TVR, TVRK from nominal size 315

Signal voltage ranges

• 0: 0 – 10 V DC
• 2: 2 – 10 V DC with shut-off function (< 0.1 V DC)

Operating modes

• Z: Supply air
• A: Extract air

Factory settings are as follows: Differential pressure ∆p_min as ordered and for room pressure controllers the adequate ∆p_nom. The effective pressure sensor of the VAV terminal unit is short circuited.

Commissioning

• On-site adjusting is not required
• When installing the VAV terminal units it is important to assign each room the correct unit based on the ordered differential pressures
• Tubing of the static differential pressure transducer by others
• For positive room pressure: Connect room pressure to Plus, reference room to Minus
• For negative room pressure: Connect room pressure to Minus, reference room to Plus
• For supply air duct pressure: Connect static pressure of the duct to Plus
• For extract air duct pressure: Connect static pressure of the duct to Minus
• After successful installation, tubing and wiring the controller is ready for use
• Carry out zero point correction for the controller and adapt the actuator.
• The differential pressure settings can be adjusted at a later stage using an adjustment device

VRP-M

Constant pressure control

The differential pressure setpoint value as given in the order code is stored as Δp_min in the controller. The nominal differential pressure Δp_nom is the reference unit.

To maximise the control accuracy, different pressure ranges with the corresponding nominal differential pressures are used. The correct range is factory set. It is possible to change Δp_min at a later stage but only within the factory set pressure range.

Variable pressure control

A setpoint value signal enables variable pressure control. The control range is Δp_min to Δp_max, based on the setpoint value signal 0 (2) – 10 V.

Volume flow and differential pressure controller VRP-M

Static differential pressure transducer VFP-100

Static differential pressure transducer VFP-600

Actuators NM24A-V and NM24A-V-ST

Actuators SM24A-V and SM24A-V-ST

Spring return actuators NF24A-V and NF24A-V-ST

Fast-running actuator LMQ24A-SRV-ST

Fast-running actuator NMQ24A-SRV-ST

VRP-M, Pressure ranges

① Min: Minimum value for ∆p_min and ∆p_max

② Max: Maximum value for ∆p_min and ∆p_max

Using a control signal also setpoint values < 30 % of Δp_nom can be set. Pressure values smaller than Δp_limit will be set to zero because they cannot be precisely controlled.

Application

• Electronic differential pressure controller VRP-STP, combined with a static differential pressure transducer VFP-100 or VFP-600, as Universal controller
• Variable or constant differential pressure control
• The differential pressure is measured using the static measurement principle
• Voltage range for the actual and setpoint value signals 2 – 10 V DC
• Separate inputs for override controls enable the centralised switching of groups of controllers

Construction

Differential pressure controller VRP-STP with static differential pressure transducer VFP-100

• BG3: Actuator NM24A-V for TVR, TVJ, TZ-Silenzio, TA-Silenzio, TVZ, TVA, TVRK
• BG1: Actuator SM24A-V-ST for TVT
• BGB: Spring return actuator NF24A-V for TVR, TVJ, TVT, TZ-Silenzio, TA-Silenzio, TVZ, TVA, TVRK

Differential pressure controller VRP-STP with static differential pressure transducer VFP-600

• BH3: Actuator NM24A-V for TVR, TVJ, TVRK
• BH1: Actuator SM24A-V-ST for TVT
• BHB: Spring return actuator NF24A-V for TVR, TVJ, TVT, TVRK

Signal voltage ranges

• 2: 2 – 10 V DC

Operating modes

• Z: Supply air
• A: Extract air

Factory settings are as follows: Differential pressure ∆p_min as ordered and for room pressure controllers the adequate ∆p_nom. The effective pressure sensor of the VAV terminal unit is short circuited.

Commissioning

• On-site adjusting is not required
• When installing the VAV terminal units it is important to assign each room the correct unit based on the ordered differential pressures
• Tubing of the static differential pressure transducer by others
• For positive room pressure: Connect room pressure to Plus, reference room to Minus
• For negative room pressure: Connect room pressure to Minus, reference room to Plus
• For supply air duct pressure: Connect static pressure of the duct to Plus
• For extract air duct pressure: Connect static pressure of the duct to Minus
• After successful installation, tubing and wiring the controller is ready for use
• Carry out zero point correction for the controller and adapt the actuator.
• The differential pressure settings can be adjusted at a later stage using a potentiometer

VRP-STP

Constant pressure control

The differential pressure setpoint value that has been ordered (order code) is factory set as Δp in the controller. The nominal differential pressure Δp_nom is the reference unit.

To maximise the control accuracy, different pressure ranges with the corresponding nominal differential pressures are used. The correct range is factory set. It is possible to change Δp at a later stage but only within the factory set pressure range.

Variable pressure control

A setpoint value signal enables variable pressure control. The control range is from Δp_limit to Δp_max.

Differential pressure controller VRP-STP

Static differential pressure transducer VFP-100

Static differential pressure transducer VFP-600

Actuators NM24A-V and NM24A-V-ST

Actuators SM24A-V and SM24A-V-ST

Spring return actuators NF24A-V and NF24A-V-ST

VRP-STP, Pressure ranges

① Min: Minimum value (10 V) for ∆p

② Max: Maximum value (10 V) for ∆p

Using a control signal also setpoint values < 30 % of Δp_nom can be set. Pressure values smaller than Δp_limit will be set to zero because they cannot be precisely controlled.

Variable pressure control requires that the link between terminals 2 and 4 is removed.

Application

• Electronic volume flow controller GUAC-S3 with integral static differential pressure transducer
• Variable or constant differential pressure control
• The differential pressure is measured using the static measurement principle
• Voltage range for the actual and setpoint value signals 0 – 10 V DC or 2 – 10 V DC

Construction

Volume flow controller GUAC-P1

• XE1: Actuator 227-024-08-V for TVR, TVJ, TVT, TVRK
• XE3: Spring return actuator 361C-024-20-V/ST07 for TVR, TVJ, TVT, TVRK

Volume flow controller GUAC-P6

• XF1: Actuator 227-024-08-V for TVR, TVJ, TVT, TVRK
• XF3: Spring return actuator 361C-024-20-V/ST07 for TVR, TVJ, TVT, TVRK

Signal voltage ranges

• 0: 0 – 10 V DC
• 2: 2 – 10 V DC with shut-off function (< 0.8 V DC)

Operating modes

• Z: Supply air
• A: Extract air

The required differential pressure is set at the factory. The effective pressure sensor of the VAV terminal unit is short circuited.

Commissioning

• On-site adjusting is not required
• When installing the VAV terminal units it is important to assign each room the correct unit based on the ordered differential pressures
• Tubing of the static differential pressure transducer by others
• For positive room pressure: Connect room pressure to Plus, reference room to Minus
• For negative room pressure: Connect room pressure to Minus, reference room to Plus
• For supply air duct pressure: Connect static pressure of the duct to Plus
• For extract air duct pressure: Connect static pressure of the duct to Minus
• After successful installation, tubing and wiring the controller is ready for use
• Carry out zero point correction for the controller using adjustment device AT-VAV-G
• The differential pressure settings can be adjusted at a later stage using an adjustment device

GUAC-P1, GUAC-P6

Constant pressure control

The differential pressure setpoint value as given in the order code is stored as Δp_min in the controller. The nominal differential pressure Δp_nom is the reference unit.

To maximise the control accuracy, different pressure ranges with the corresponding nominal differential pressures are used. The correct range is factory set. It is possible to change Δp_min at a later stage but only within the factory set pressure range.

Variable pressure control

A setpoint value signal enables variable pressure control. The control range is Δp_min to Δp_max, based on the setpoint value signal 0 (2) – 10 V.

Differential pressure controller GUAC-P1

Differential pressure controller GUAC-P6

Actuator 227-024-08-V

Spring return actuator 361C-024-20-V