Why is a precipitation sensor used?

Reliable detection of precipitation is crucial in many areas of application – from traffic control technology to sewage treatment plants and building management. Incorrect or delayed precipitation detection can lead to accidents, inefficient processes or damage to property.

The IRSS88 and IRSS88T precipitation sensors from RLS Wacon are opto-electronic precipitation detectors that have been used successfully for years in traffic control systems, sewage treatment plants and building management worldwide. They reliably detect all types of atmospheric precipitation – rain, drizzle, hail and snow – and impress with their instantaneous response and extreme robustness. The IRSS88T also offers integrated temperature measurement with 0.1 °C resolution, potential-free relay outputs and an RS232 interface.

How do the IRSS88 / IRSS88T precipitation sensors work?

Based on a light barrier principle with high-performance infrared technology, the sensors generate an active detection area of approx. 120 × 25 mm. This area is sufficient to reliably detect even low precipitation densities with the smallest particle sizes.

The opto-electronic principle reacts instantaneously to particles that pass through the sensor zone. The highly sensitive microelectronics are insensitive to any kind of interfering light – even intense sunlight. The all-metal housing ensures effective shielding against HF radiation.

Signal outputs IRSS88

The IRSS88 has three signal outputs:

All outputs are designed as PNP open collectors and require pull-down resistors (recommended: 1-10 kΩ). All outputs are short-circuit proof.

Additional functions of the IRSS88T

The IRSS88T contains a separate temperature sensor in an aluminum attachment on the core housing. This makes it possible to measure the ambient temperature to an accuracy of 0.1 °C and to control a potential-free switching output via a switching hysteresis function. The hysteresis can be set as required between 0 °C and 9 °C using two rotary selector switches.

Adjustable response threshold

The response threshold of the weighted output SOUT can be set to 1 to 15 pulses per time interval (approx. 95 s) using a rotary switch on the receiver circuit board. This allows the signaling of insignificant amounts of precipitation to be suppressed. The factory setting is 4 pulses.

Advantages of the IRSS88 / IRSS88T precipitation sensors

• Reliable detection of all types of precipitation

  Rain, drizzle, hail and snow are reliably detected even with the smallest particle size

• Delay-free reaction

  The opto-electronic principle reacts immediately to particles in the sensor zone

• Extremely robust stainless steel housing with protection class IP68

  Waterproof all-metal housing made of stainless steel (V2A) – suitable for extreme environmental conditions

• Insensitive to interfering light

  Reliable operation even in intense sunlight thanks to highly selective IR technology

• Alarm output for soiling

  The SACT output informs the operator if the sensor windows are heavily soiled or iced up

• Connection cable up to 1000 m possible

  Wide operating voltage range (9-18 V DC) and low current consumption enable long cable runs

• Adjustable response threshold

  Rotary switch for 1-15 pulses per time interval – insignificant amounts of precipitation can be suppressed

• IRSS88T: Integrated temperature measurement with 0.1 °C resolution

  Separate temperature sensor with adjustable switching hysteresis, analog temperature output and RS232 data protocol

Der Beitrag Precipitation sensor IRSS88 erschien zuerst auf RLS Wacon analytics.

Why is the speed monitored on escalators?

Speed monitoring is a safety-critical element in every escalator. According to the European standard EN 115:2008, escalators must be equipped with a reliable speed monitoring system that switches off the motor immediately in the event of dangerous speed deviations. An incorrect speed can lead to serious accidents – whether due to sudden acceleration (overspeed), unexpected braking (underspeed) or a reversal of direction.

The RC3 speed monitor from RLS Wacon is a TÜV type-tested safety component that has been used successfully in escalators and moving walks worldwide for many years. It reliably monitors three speed ranges and detects four different hazardous conditions, each of which leads to the escalator motor being switched off immediately.

How does the RC3 speed monitor work?

The RC3 detects the speed of the escalator motor via two inductive proximity switches (NAMUR sensors), which are attached to the flywheel of the motor. The sensors are supplied with 9 V DC directly from the device (max. 50 mA per output) and do not require an external voltage source. Both 2-wire sensors (NAMUR) and 3-wire sensors can be adapted.

The device continuously monitors three speed ranges and distinguishes between four switch-off criteria:

Each time the mains voltage is switched on, the RC3 performs an automatic self-test (max. 2.8 seconds). The sensors are switched off and all four switch-off conditions are simulated by an internal sweep generator. Only after a successful self-test and closed motor contactor contact does the green “NORMAL” LED light up and the output relays enable the motor.

The safety output for staircase control contains two potential-free normally open contacts (terminals 17/18) connected in series internally, which are looped into the safety chain and protected against overload with fuse F2 (2 Atr.). The STATUS terminal strip also has potential-free contacts for the status signal (NORMAL/FAULT) and a conditioned sensor signal (optocoupler output).

The first fault leading to shutdown is indicated by one of the four LEDs on the front panel (LO, HI, SENS FAIL, NORMAL). The device can only be reset by pressing the RESET button – locally or via the external RESET input (pin 1/2) – after it has been checked by qualified personnel. In the event of a sensor fault or internal error, a restart is not possible without prior troubleshooting.

Available sensor nominal frequencies

The RC3 is available in six different nominal sensor frequencies. The nominal frequency corresponds to the pulse frequency of the sensor at 100 % nominal speed of the escalator motor:

Advantages of speed monitoring RC3

• TÜV type-tested in accordance with EN 115:2008

  Certified safety for use in escalators in accordance with the European standard

• Six nominal sensor frequencies available

  66⅔, 80, 100, 250, 333 and 500 Hz – suitable for various gear ratios and cam numbers

• Automatic self-test every time the device is switched on

  All four switch-off conditions are simulated internally – maximum operational safety

• Four independent switch-off criteria

  Underspeed, overspeed, reversal of direction of rotation and sensor failure are reliably detected

• Compact design with DIN rail mounting

  64 × 104 × 135 mm – easy installation in the switch cabinet, vertical or horizontal

• Low power consumption under 5 VA

  Energy-efficient in continuous operation at 230 V AC

• Integrated sensor supply 9 V DC

  No external voltage source required for the proximity switches – 2-wire (NAMUR) and 3-wire compatible

Der Beitrag Speed monitoring RC3 erschien zuerst auf RLS Wacon analytics.

• Original RUDOLPH design
• For new installations, we recommend the e-version

The composition of complete standby circuits is shown in the table below.

Example
For a standby circuit with 58 photocells, 2 chains with 9
modules, 4 chains with 10 modules, 5 connection modules, an adapter cable and an end module for the transmitter and
receiver side are required according to the following table.
The distance between the modules in the base plate must be less than 30 cm, in the curved area only 20 cm!

Der Beitrag Light curtain C version erschien zuerst auf RLS Wacon analytics.

Der Beitrag Connection modules for C version erschien zuerst auf RLS Wacon analytics.

SL800:

Der Beitrag Step gap lighting SL800 erschien zuerst auf RLS Wacon analytics.