So-called ‘dirty power’ caused by noise and harmonic distortions can severely impact the reliability of electronic equipment within production and process control environments. These facilities are continually under pressure to maintain optimum availability by avoiding unexpected interruption and system downtime while at the same time guarding against unplanned increases in power consumption.
Efficient operation of modern systems depends upon transient-free power for optimised performance and while every manufacturing environment requires different levels of protection, Bender UK’s industrial power specialists can offer a broad range of solutions that can be tailored to address each power quality problem, with innovative products employing proven technology to optimise a facility’s efficiency, productivity, and longevity.
The increasing number of system components across the manufacturing and processing infrastructure means more equipment drawing power from the network and greater dependency on power quality.
As electrical supply systems become ever larger it is not unusual for overloaded networks to result in failures and disturbances. Before further expansion takes place, a monitoring system comprising universal measuring devices of the PEM series enables operations and maintenance teams to assess risks from overloads and changes in energy consumption or potential impacts on protective measures and energy costs.
High harmonic components in the design current can lead to overloading in wiring systems and even cause fires. These effects have already been addressed in the standards; recommendations for the adaption of the conductor cross section in the event of high harmonic components are specified in IEC 60364-5-52:2009 for example. If an overloading of the neutral conductor is to be expected due to harmonics, IEC 60364-4-43:2008 recommends overload detection for the neutral conductor.
Early warning alerts
The effectiveness of such measures largely depends on the operational status of the electrical installation. Evaluation can be achieved only by continuous monitoring of the harmonic content and by measuring the operational currents in order to ensure safe and secure operation of the electrical installation.
The goal of a monitoring system must be to recognise even small changes in measures such as current leakage or harmonic content, and to generate an early warning.
However, trend curves of power quality or current leakage can’t be achieved using a single measuring point in an electrical installation. Several measuring points need to be installed and adapted to correspond to the structure of the system.
A monitoring system generates several measured values per second. All measured data can now be displayed on the new generation gateway Comtraxx CP700 Condition Monitor which is capable of automatically collecting, evaluating and processing this information to take account of the user groups. It also delivers information on energy consumption to bring transparency to electrical service networks when used in conjunction with Bender Linetraxx power quality monitoring (PQM) systems.
Improving system availability
At its most basic level, protecting systems means being aware of the risks and choosing the equipment which is able to provide early warning or immediate notification when problems arise.
Linetraxx power quality monitoring (PQM) units from Bender UK mitigate these risks and provide the ability to predict and prevent problems, while also reducing costs and avoiding issues caused by ‘dirty’ power systems suffering from interference.
They are designed to meet the needs of customers who can’t afford failures and are available alongside Bender’s residual current monitoring (RCM) units and advanced on-line earth fault location systems to offer a complete solution to deliver robust and stable power systems in production and process environments.
Interference in modern power systems can result from a number of sources which distort the sine wave of the electrical power and superimpose different frequencies on it – causing the power supply to become ‘dirty’.
The most frequent problems result from harmonic components on the electrical supply – typically produced by other items of electronic equipment. These ‘third order harmonics’ build up in the neutral conductor and in extreme cases the resulting current can be greater than the individual phase currents. This leads to neutral conductor overload and – if the situation goes unnoticed – there can even be a risk of fire.
Regulations require overload detection for the neutral conductor if an excessive load is anticipated due to harmonics, and it should ensure a protective device trips out thereby protecting the neutral conductor. But this safety measure simply moves the problem elsewhere – resulting in reduced availability due to frequent downtime.
Power quality monitoring
Bender’s monitoring equipment enables early detection of potentially dangerous situations – allowing time to correct the problem without the need to shut down equipment.
Power quality monitoring is particularly effective when combined with residual current monitoring (RCM) which detects degradation in the level of insulation in an installation or component – again improving availability by signalling the problem at an early stage before safety shutdown or power outage.
Bender’s PQM devices also act as energy meters while checking the system quality, determining the energy consumption per cost centre and reducing high overhead costs. For example, the PQM device can determine how much energy is consumed by the measures taken to prevent system interaction, and will also show the effect of energy-saving measures on the quality of the electrical supply system.
The dual function of monitoring energy consumption and energy quality helps to reduce energy costs while at the same time delivering high availability of supply.
Structural detail is a crucial element for effective energy management and cost control in a complex installation, because energy use must be identified for each cost centre and each different device. Moreover, power quality management and energy measurement devices can identify individual faults only if the system area monitored is clearly defined.
Effective energy management
In a typical system a Bender PEM 735 monitors the quality of the voltage for the supply, delivering high resolution logging through measurement of transients, flicker and harmonic components.
It offers versatile functionality by combining Class 0.2S revenue accuracy and advanced PQ monitoring for sag/swell, transient and flicker, all within a standard DIN 192 form factor, with a stunning high resolution industrial grade, colour TFT 5.7” LCD display.
Moreover, the unit also offers data logging capacity with up to 8GB of on-board memory, extensive I/O with 8xDIs and 8xDOs, hardware GPS time synchronisation and multiple communications options that include redundant Ethernet and dual RS-485 ports. The unit is PQDIF and COMTRADE compatible.
Outlets on the main low voltage distribution system are monitored by PEM 5 series devices; the sampling rate is 12.8kHz and as a result events are clearly shown in the data logged.
The PEM 5 series offers advanced power quality and revenue-accurate measurements, high-resolution waveform recording capabilities, comprehensive data logging with a 4MB log memory, high speed data recording, setpoint alarms, extensive I/O and standard dual RS-485 ports and Modbus protocol support.
PEM 3 series compact universal measuring devices are positioned to replace energy meters and represent cost centres. This effectively creates an energy management system to control overhead costs for electrical power. This type of monitoring system configuration ensures quick and straightforward analysis to locate power quality phenomena which may put the installation at risk
Suitable for a range of applications from measuring currents and voltages through energy consumption and performance to total harmonic distortion and voltage quality assessment, PEM 3 series active energy measurements are in compliance with DIN EN 62053-22 Class O.5s accuracy standard. Each collects relevant data for energy management systems and tracks energy consumption for allocation to cost accounting centres. The PEM 3 series can also provide information on the overall harmonic content in the part of the installation being monitored.
Bender’s PEM 3 series and PEM 5 series compact devices are designed for front panel mounting as replacements for analogue indicating instruments, with typical applications in low and medium-voltage networks (via measuring voltage transformer).
All measured data can then be displayed on the new generation gateway Comtraxx CP700 Condition Monitor for complete transparency of electrical service networks.
Comtraxx CP700– power monitoring at your fingertips
The Comtraxx CP700 Condition Monitor from Bender UK new generation gateway provides a comprehensive view of energy consumption and introduces a new level of transparency to electrical service networks.
Used in conjunction with Bender Linetraxx power quality monitoring (PQM) systems, it enables the collection, filtering and evaluation of all measured data at a central point.
Comtraxx CP700 displays currently measured values, operating and alarm messages from Bender BMS and Power Quality devices on the touch screen, and provides remote indication of data from Bender BMS and Power Quality devices using a standard web browser with Silverlight plug-in.
The unit is designed to offer time synchronisation for all BMS bus devices, easy address setting via touch screen, and Modbus/TCP data access to the first 10 devices.
Fast, simple parameter setting of BMS devices uses the web browser. The report function saves measured values and settings, and those saved settings can be compared with the current settings and can be reloaded.
Features include assignment of individual texts for devices and measuring points (channels) and alarms, monitoring for device failure, and e-mail notifications to different user groups according to a time controlled schedule in the event of alarms and system faults
Access to all Bender devices assigned to the CP700 is via the integrated Modbus/TCP server (max. 247 devices). An external application, such as visualisation or SPS, allows devices to be controlled via Modbus/TCP
Comtraxx CP700 offers fast and easy visualisation on a personal computer without previous knowledge of computer programming. Measured values or alarms can be displayed in front of a graphic (system diagram, room plan), and the unit is capable of supporting multipage documents.
Visit www.bender-uk.com/products/power-quality.html for further technical information.