Operating modes and wiring

<< Click to Display Table of Contents >>

Navigation:  Humidity & Temperature Devices > Transmitter > HF3 >

Operating modes and wiring

The safety of the installed system, where the device is integrated, is the responsibility of the builder of the system.

 

 

 

General guidelines

 

Power supply wiring

Heavy machinery and instrumentation should not share the same power supply wiring. If this cannot be avoided, noise filters and surge protectors should be used. Most UPS devices have those features already integrated.

 

General guidelines for signal cables

The following guidelines are derived from European Standard EN 50170 for the transmission of signals by copper wires. When planning an installation, the rules provided by EN 50170 should be followed under consideration of local circumstances to determine the position of machines and equipment.

All ROTRONIC products are tested for Electromagnetic Compatibility according to EMC Directive 2004/106/EG and following European standards:

- EN 61000-6-1: 2001, EN 61000-6-2: 2005

- EN 61000-6-3: 2005, EN 61000-6-4: 2001 + A11

Whenever the level of electromagnetic interference is expected to be high, both the instruments and signal cables should be placed as far away as possible from the source of interference.

In general, signal cables should be installed in bundles or channels / conduits, separate from other cables as indicated in the table below:

 

Bus signals such as RS485

Data signals for PCs, printers etc.

shielded analog inputs

unshielded direct current (<= 60V)

shielded process signals (<= 25 V)

unshielded alternate current (<= 25V)

coaxial cables for CRT monitors

in common bundles or channels / conduits

direct current from 60 V to 400 V (unshielded)

alternate current from 25V to 400 V (unshielded)

in separated bundles or channels /

conduits, without minimum distance /

direct and alternate current > 400 V (unshielded)

Telephone lines

lines leading into EX-rated areas

in separated bundles or channels /

conduits, without minimum distance

 

Lightning protection

Cabling in areas with a risk of lightning requires a lightning protection. For cabling underground in between buildings, we recommend the use of special fiber optic cables. If this is not possible, use copper cables that are suitable for underground installation.

 

 

 

Cable grip and cable specifications

Both type D and type W have one M16 sealing cable grip. This cable grip provides effective sealing only with cables having the proper outside diameter. Preferably, use a cable with an outside diameter of 6 to 7 mm (0.236 to 0.275 inch) with 18 AWG wires.

 

 

 

Wiring

 

HF32: 2-wire, loop powered transmitter

 

HF3-2wire-loop-powered-electricaldiagram

 

The maximum permissible cable length connecting the HF32 to other devices is determined by the total resistance resulting from the addition of the cable resistance and that of the devices connected in series with the unit. This resistance should not exceed 500 ohms.

 

 

HF3-2wire-loop-powered-terminal-block-diagram

 

 

Measuring humidity or temperature only

Unless configured to measure either humidity only or temperature only, proper operation of the HF32 requires both current loops to be closed. The HF32 can be directly ordered from the factory to measure either humidity or temperature only. When necessary, any unused output of the HF32 can be disabled with the ROTRONIC HW5 or HygroSoft software. When the HF32 is configured with one of the two outputs disabled, close only the loop that is being used.

 

 

 

HF33: 3-wire transmitter

 

HF3-3wire-transmitter-electrical-and-terminal-block-diagram
HF3-3wire-transmitter-terminal-block-diagram

 

 

Measuring humidity or temperature only

Operation of the HF33 does not require both current loops to be closed. When using the HF33 to measure either humidity only or temperature only, close only the loop that is being used.

If necessary, any unused output of the HF32 can be disabled with the ROTRONIC HW5 or HygroSoft software.

 

 

 

Grounding (HF32, HF33)

We generally recommend grounding the (-) side of the power supply, especially if the electronics will be subjected to a low humidity environment (35 %RH or less).