HygroFlex5-EX & HygroClip2-EX Short Instruction Manual

1 Overview

The HygroFlex5-EX is a humidity and temperature transmitter designed for fixed installation in applications requiring high measurement accuracy. These transmitters are compatible with all Rotronic ATEX sensors from the AirChip 3000 series. Standard sensors must not be used. The electronics' operating temperature range is limited to -40...60 °C (-10...60 °C with an optional LCD display).

For more information, visit ProcessSensing.com or rotronic.com, or scan the QR code to access the Rotronic online manual for further explanations.

2 Commissioning

HygroFlex5-EX (2-wire circuit, loop-powered): Requires 10...28 VDC depending on the loads connected to the outputs. The minimum supply voltage can be determined as follows:

V_min = 10 V + (0.02 A x Load*) *Load resistance in Ohms.

For a maximum load of 500 Ω, the minimum supply voltage is 10 V + (0.02 A x 500 Ω) = 20 VDC. If both output circuits are closed, the maximum current consumption during operation is 40 mA. The device must be correctly closed during operation to ensure explosion protection.

3 Grounding

The HygroFlex5-EX must be grounded via the grounding connection on the housing.

4 Starting the Device

The device requires approximately 1 minute for the entire start-up process. After about 20 seconds, "Please wait" will appear on the display. During this time, both analog signals will increase to approximately 21 mA. The device will then start operating, and the analog outputs will adjust to the corresponding measured value after the first measurement interval.

5 Service Connector

The service connector (UART interface with a mini-USB connector) allows connecting the HygroFlex5-EX to a PC running the Rotronic HygroSoft software. A service cable is required. Refer to the "Maintenance" chapter for the location of the service connector and the type of service cable.

WARNING: The service interface is a UART interface with a mini-USB connector. Do not connect the service interface directly to a USB port; use only the AC3006 service cable!

The service interface is located inside the device. To access it, the device cover must be removed after loosening the 4 screws. The device must not be located in an explosive zone during service work!

6 Electrical Scheme

The electrical scheme shows the transmitter, sensor, and power supply connections. It indicates primary and secondary sides with different protection types (Ex-mb-verguss, Ex-ia-vergossen) and zones (Zone 1, Zone 0). Galvanic isolation is present. An optional LCD display is also indicated.

Power Supply:

• Supply Vs. Hyg: +20 VDC to +28 VDC
• Supply Vs. Temp: +20 VDC to +28 VDC

Signals:

• Signal Sig_Hyg: +2 V to +10 V
• Signal Sig_Temp: +2 V to +10 V

Load Resistance: 500 Ω

Internal Components: Z-barrier, 2x 6V2, 1x 5V6, 32mA (likely current limit or output indication).

7 Commissioning

Various mounting options are shown:

• Wall Mounting: For non-explosive areas, with HC2-SM-EX probe in Zone 1/21 or Zone 0/20.
• Duct Mounting: Similar probe placement.
• Wall Mounting with Cable Sensor: Using AC1301-MEX cable gland, with HC2-Mxxx-EX probe (2/5/10 m cable, 130/280 mm probe) in Zone 1/21.
• Wall Mounting with Screw-in Sensor: Using AC1301-MEX cable gland, with HC2-Exxx-EX/HC2-LDPxxxx-EX probe (2/5/10 m cable, WG/NPT thread) in Zone 1/21 or Zone 0/20.

8 Wiring

According to EN60079-14, no SELV device is required for the power supply (SELV supply = with limited transients). The measuring transducer can also be operated with only one closed measuring loop.

Cable Gland:

• Clamping range: 4.5 - 10 mm (non-armored cable)
• Tightening torque: 10 Nm

9 Periodic Check (Calibration) of the Sensor

The PT-100 RTD temperature sensor and electronics used in the probe are highly stable over the long term and generally require no further calibration after the initial factory adjustment. The long-term stability of Rotronic's hygrometer humidity sensor is typically better than 1% RH per year. For maximum accuracy, the sensor's calibration should be checked every 6 to 12 months. Applications where the sensor is exposed to significant contamination may require more frequent checks.

Note: The HygroClip 2 sensor cannot be adjusted when connected to the HygroFlex5-EX transmitter.

10 Repair

Do not attempt to repair defective appliances yourself. The appliance must be sent to the manufacturer's service center for repair.

11 Replacement Filter

Steel sintered filter: SP-FN15

12 Power Supply

Two separate connections are available for the humidity and temperature sensors. The measuring device connections include power supply and sensor signal. The supply voltages for the two sensors may differ as they are decoupled by two internal diodes. The device can also be operated with a single loop.

Device Input Voltage: USupply = 20 V...28 VDC [24 V +/- 15%]

Maximum Current: ISupply max. = 50 mA [Sum of both input currents]

Load: RM = 0...500 Ω [Measuring voltage 0 V...10 V]

Ambient Temperature Range:

• Measuring Sensor: TA = [-40 °C...+85 °C]
• Transmitter with LCD: TA = [-10 °C...+60 °C]
• Transmitter without LCD: TA = [-40 °C...+60 °C]

The usual ATEX standards apply only for normal temperature [-20 °C...+40 °C] and a pressure range of [0.8 bar...1.1 bar]. The extended temperature range must be noted on the rating plate.

13 Input Protection Circuit

The device is protected against reverse polarity by two diodes. Additionally, two Z-transit diodes protect against static and transient overvoltages. These measures are not required by ATEX but have been implemented as easily realizable supplementary protective measures.

Supply Circuit Sensor*:

• Maximum Output Voltage: Uo ≤ 6.6 V
• Maximum Output Current: Io ≤ 82 mA
• Maximum Output Power: Po ≤ 485 mW
• Capacitance: Co = 22 µF
• Inductance: Lo = 2 µH

HC2-LDPxxx-EX Sensor Circuit*:

• Maximum Input Voltage: Ui ≤ 6.6 V
• Maximum Input Current: Ii ≤ 82 mA
• Maximum Input Power: Pi ≤ 485 mW
• Internal Capacitance: Ci = 19 µF
• Internal Inductance: Li = 0

All Other Sensors Sensor Circuit*:

• Maximum Input Voltage: Ui ≤ 6.6 V
• Maximum Input Current: Ii ≤ 82 mA
• Maximum Input Power: Pi ≤ 485 mW
• Internal Capacitance: Ci = 15 µF
• Internal Inductance: Li = 0

*Type of ignition protection: Intrinsic safety Ex ia IIC.

14 ATEX Data

15 Nameplate Information