Mitsubishi SIKA VVX20 PAC-FS01-E Flow Meter

The Mitsubishi Electric PAC-FS01-E SIKA VVX20 flow meter is a flow sensor designed to measure water flow in Ecodan air-to-water heat pump installations and transmit this information to the system’s FTC controller. It allows the control system to monitor the flow in the hydraulic circuit and is a necessary or optional component depending on the specific combination of outdoor unit and controller used.

The PAC-FS01-E is especially suitable for open-solution Ecodan configurations, where the different hydraulic components are selected and installed separately. Mitsubishi Electric includes this flow meter in systems with FTC controllers as well as in certain monobloc solutions, and it is mandatory in some configurations to ensure proper monitoring of the hydraulic circuit.

Key features of the Mitsubishi Electric PAC-FS01-E

• Brand: Mitsubishi Electric.
• Reference: PAC-FS01-E.
• Commercial model code: 7H1FS01.
• Product type: flow sensor / flow meter.
• Commercial name: SIKA VVX20.
• Application: Ecodan air-to-water heat pump systems.
• Function: measurement of hydraulic circuit water flow.
• Control connection: FTC controller via CN1A connector.
• Sensor power supply: 5 V DC from the control board.
• Output: analog flow signal Vout.
• Ambient temperature: 0 to 70 °C.
• Fluid temperature: 5 to 90 °C.
• Installation: horizontal or vertical.
• Minimum straight inlet length: 190 mm.
• Minimum straight outlet length: 95 mm.
• Included cable length: 5 m.

Flow measurement in Ecodan systems

The PAC-FS01-E continuously measures the water flow circulating through the hydraulic circuit. This information is sent to the FTC electronics so the system can monitor the operating conditions of the installation.

A proper water circulation is essential in an air-to-water heat pump. Insufficient flow can affect heat exchange and system performance, so having a flow signal allows the control system to know the real hydraulic behavior of the installation.

Accessory for Mitsubishi Electric Ecodan air-to-water heat pumps

The PAC-FS01-E flow meter is part of Mitsubishi Electric’s accessories for Ecodan systems. It is especially related to open-solution configurations, in which the FTC controller, circulation pump, heat exchanger and other components are configured according to the project requirements.

The need to include this sensor depends on the combination used. Mitsubishi Electric specifies it as mandatory in certain hydraulic solutions and optional in others.

Compatibility with FTC controllers

The official manual includes the flow meter connection for different generations of Mitsubishi Electric controllers, including:

• PAC-IF07*B-E.
• PAC-IF033****-E.

On PAC-IF07*B-E controllers, the flow meter signal is connected to input INA1, corresponding TBI.4 terminals, and the CN1A connector. On PAC-IF033****-E variants, the CN1A connector is also used.

Final compatibility should always be checked with the specific outdoor unit and FTC generation used in the installation.

Mandatory in certain Ecodan configurations

Mitsubishi Electric expressly indicates in the manual that the PAC-FS01-E must be installed for safety reasons in certain equipment combinations.

Among the configurations specified by the manufacturer are systems with:

• Outdoor unit: PUZ-(H)WM****A.
• Controller / indoor unit: PAC-IF072B-E.

The manufacturer also considers it an optional accessory in certain combinations with outdoor units from the following families:

• SUZ-SWM**VA.
• PUD-S(H)WM***AA.
• PUHZ-S(H)W*****A.

These configurations may be associated, depending on the system, with controllers such as PAC-IF071B-E or PAC-IF033****-E.

Mandatory accessory in certain open solutions

In current generations of Ecodan open solutions, Mitsubishi Electric also considers the PAC-FS01-E a mandatory accessory in certain combinations with FTC control.

For this reason, before carrying out an open-solution Ecodan installation, it is advisable to consult the corresponding compatibility table for the exact generation of outdoor unit and controller.

Horizontal or vertical installation

The flow meter can be installed in both horizontal and vertical pipes. This flexibility makes it possible to adapt its position to the hydraulic layout available in the technical room or installation area.

However, Mitsubishi Electric states that the sensor must always operate with the pipe completely full of water.

Avoid air and partial pipe emptying

The installation position is important to ensure correct reading. The manufacturer indicates that areas where the following may occur should be avoided:

• Air pockets or air bubble formation.
• Partial emptying of the pipe.
• Operation with the measuring tube partially filled.

These situations can alter the flow reading and affect the information sent to the controller.

Minimum straight sections for stable measurement

Mitsubishi Electric specifies minimum straight pipe distances around the sensor:

• Minimum straight section before the flow meter: 190 mm.
• Minimum straight section after the flow meter: 95 mm.

Respecting these distances helps stabilize the flow before it passes through the sensor and contributes to a more reliable measurement.

Installation with mixing tank

When the system uses a mixing tank, Mitsubishi Electric indicates that the flow meter must be installed between the tank and the plate heat exchanger.

In the manufacturer’s hydraulic diagram, the sensor works together with the supply and return temperature thermistors and the circuit circulation pump.

Analog signal to the FTC board

The PAC-FS01-E is electrically connected to the FTC controller board and generates a Vout output signal proportional to the detected flow.

The official electrical diagram uses a 5 V DC supply provided by the controller and an analog signal interpreted by the FTC board microprocessor.

The graph published by Mitsubishi Electric shows the relationship between flow rate and output voltage, with a signal that starts at approximately 0.35 V and increases progressively as flow increases.

Configuration using DIP switches

After physically installing the sensor, the corresponding controller must be configured to indicate that a flow meter is connected.

The manual sets the following configurations:

• PAC-IF07*B-E: DIP switch SW2-8.
• PAC-IF033****-E: DIP switch SW4-2.

The OFF position corresponds to operation without a flow sensor, and the ON position tells the controller that the flow meter is installed.

Water operating temperature

The sensor is designed to operate with a fluid temperature between 5 and 90 °C, making it suitable for heating and air-conditioning hydraulic circuits compatible with Ecodan specifications.

The permitted ambient temperature around the sensor is between 0 and 70 °C.

SIKA VVX20 measurement technology

The PAC-FS01-E is sold as a SIKA VVX20 flow meter. SIKA’s VVX family uses vortex flow measurement technology and is specifically designed for measuring water and aqueous solutions.

This measuring principle does not require a conventional mechanical rotor in the water path. The flow generates vortices whose frequency can be detected by the sensor and converted into an electrical signal proportional to the flow rate.

Items included with the PAC-FS01-E

According to Mitsubishi Electric’s official manual, the accessory includes:

• 1 flow sensor body.
• 1 black 5 m connection cable.
• 2 O-rings.
• 1 installation manual.

Additional hydraulic circuit components, such as the circulation pump, plate heat exchanger or mixing tank, are not part of this accessory unless expressly included in the supply of the complete system.

Applications of the Mitsubishi PAC-FS01-E flow meter

This sensor is especially suitable for:

• Mitsubishi Electric Ecodan air-to-water heat pump systems.
• Open solutions with FTC controller.
• Ecodan monobloc systems requiring external flow measurement.
• Installations with plate heat exchangers.
• Hydraulic circuits with mixing tank.
• Projects where the controller needs to monitor water flow.
• Configurations where Mitsubishi Electric specifies the flow meter as a mandatory accessory.

Installation recommendations

To obtain a correct reading, it is important to follow the manufacturer’s instructions:

• Disconnect the power supply before installing the accessory.
• Make electrical connections without mechanical stress on the terminals.
• Install the sensor only in a pipe that is completely full.
• Avoid positions where air may accumulate.
• Avoid areas where the pipe may be partially empty.
• Maintain at least 190 mm of straight pipe before the sensor.
• Maintain at least 95 mm of straight pipe after the sensor.
• Correctly configure the FTC controller DIP switches.
• Perform an operating test after installation.

Technical data for the Mitsubishi Electric PAC-FS01-E

• Manufacturer: Mitsubishi Electric.
• Reference: PAC-FS01-E.
• Commercial model code: 7H1FS01.
• Description: flow meter / flow sensor.
• Commercial model: SIKA VVX20.
• Application range: Ecodan.
• Fluid: hydraulic circuit water.
• Fluid temperature: 5-90 °C.
• Ambient temperature: 0-70 °C.
• Power supply from controller: 5 V DC.
• Signal type: analog Vout output proportional to flow.
• Control connector: CN1A.
• Installation: horizontal or vertical.
• Operating condition: pipe completely full.
• Minimum inlet straight section: 190 mm.
• Minimum outlet straight section: 95 mm.
• Included cable: 5 m.
• Included O-rings: 2.
• EAN: 5051467010687.

Flow meter for monitoring the Ecodan hydraulic circuit

The Mitsubishi Electric PAC-FS01-E SIKA VVX20 makes it possible to add flow measurement directly to the Ecodan control system. The information provided by the sensor allows the FTC controller to know the flow in the hydraulic circuit and monitor that the installation is operating within the expected conditions.

Its ability to be mounted horizontally or vertically, the included 5 m cable and the direct connection to the FTC electronics make it easy to integrate into open-solution air-to-water heat pump projects. In certain combinations, Mitsubishi Electric expressly specifies this flow meter as a mandatory element, so compatibility with the outdoor unit and controller used must always be checked.