PGR8800 Vlamboog detector

An arc fault is properly the most destructive fault senario that can happen within an electrical installation. Arcs develop when the insulation between conductors are broken down sufficiently to leave an ionized channel which can carry current. Insulation can be degraded for different reasons, e.g. conductive dust, moisture, cobwebs etc. If the switchboard is capable of supplying enough energy, a run-away reaction can occur,  if this happens the current heats and ionizes more air, carrying even more current, heating up and eventually boiling the conductors. The following explosion will spray the cabinets with molten copper and tear it apart by the rise in pressure - this happens as the arc fault converts the full capacity of the power source to heat.

Watch the complete movie from teh D1000 Littelfuse Selco

The damage can be so extensive that it will take days or even weeks to re-establish production. However, even more serious is the risk of personal injury. Arcs can and do kill people by explosions, shock waves, shrapnel, extreme heat etc. Arc protection is one way to lower the risk of disaster, even though it is not a replacement for personal protection (PPE equipment).

It is not generally possible to extinguish a developing arc, but the damage can be limited by cutting the power to the switchboard as soon as possible.

In case of an arc flash fault, the D1000 detects and generates a tripping pulse in less than 1 millisecond. This tripping pulse is taken to the circuit breaker(s) that controls the supply to the installation. The total arcing time is thus reduced to the mechanical opening time of the circuit breaker, which is typical around 30-100 milliseconds. If even shorter arcing time is required, the D1000 can control arc quenching devices as well as breakers, limiting the arc time to less than 2 ms.

The trip circuit is based on a solid state semiconductor switch (IGBT), which provides both fast reaction as well as drive capability for even the largest circuit breakers

Optical point- & fiber sensors

One side effect of the arc energy conversion, is a lot of visible light. The D1000 detects this light and reacts on it to provide the tripping signal.

The D1000 supports up to 6 sensors, which can be any combination of point sensors and fiber optical line sensors. Unlike the competition, the sensors can be mixed and matched freely according to the requirements. The sensors are optimized for easy installation and best possible coverage of the switchboard. Each sensor is supplied with 10 m of connecting cable. The sensors can be pop riveted directly into the system, and include local LED bsed indication of operational status as well as alarms.

The point sensor is sensitive to light from all angles towards the point where it is installed. The line sensor is sensitive to light over its 8 m exposed length, and can thus cover multiple sections of the switchboard.

D1000 provides continuous surveillance of the complete system including the cables and connected sensors. Any fault from a broken cable to loss of power is indicated on a relay output, on the front panel, and within the log. The D1000 can also be made available to SCADA systems using RS485 MODBUS RTU.

For more information on the individual sensor types, please refer to the side menu.

Easy Installation

The D1000 makes it easy to verify that all sensors are correctly installed and equally sensitive. By using the built-in calibration sensor, any flashlight or other light source can be used to test the sensors. First, the user points the flashlight at the calibration sensor on the front panel, closing the distance until a LED on the front panel indicates that the light is at the trip threshold. After noticing the distance, the other point sensors can be tested – all sensors should trip when the flashlight is held at an equal distance. In smaller installations, the calibration sensor on the front panel can be used as a single arc detecting sensor, minimizing the cost of comissioning.

The D1000 can be installed and commissioned as-is, without any on-site configuration needed. However, special configurations, e.g. setup of the overcurrent sensor, are easily done through the on-board USB interface. A user-friendly menu system is provided, and multiple units can also be programmed by simply dragging and dropping the configuration text files to the unit. The USB connection also provides easy access to a real-time event log, which provides detailed diagnostic information about each and every event, including near misses and events related to daily operation (e.g. configuration changes, test, reset, and power cycling).

On-board Current Sensor

D1000 includes a 3-phase current measurement with a reaction time of less than 1 millisecond.

The sensor is intended for inhibiting trips unless a substantial current is being consumed. This can reduce unintended tripping from e.g. lightning flashes or welding without the traditional extra delay and expense of an external overcurrent relay.

The overcurrent and short circuit functions can be used to trip the breaker in case of short circuits or long-lasting overloads without arching.

The current sensor is intended for current transformers with a secondary current of 5A nominal. Each phase is completely isolated and has a very low burden, and can thus often be used in series with existing CTs and measurement equipment.

The D1000 is the only system to provide all functions in one single unit.

Setup without PC

For most installations, no configuration is needed. The D1000 is thus just as fast and easy to set up and test as the SELCO D0100/D0900 based solutions. The self-diagnostics system provides better confidence in the installation. A final test of all optical sensors and functions can be done with only one trip of the system.

In the case of more advanced installations, the D1000 can be configured using the USB interface at the front. The built-in user-friendly menu system is embedded in the D1000 and activates automatically when the unit is connected to a PC via the USB interface, and no external units or installation of software on the service PC is required – except for the standard USB cable.

USB for access to log

The built-in USB connection also provides easy access to an internal event log, which provides detailed diagnostic information about all events, including near misses and events related to daily operation (e.g. configuration changes, test, reset, and power cycling). D1000 will even draw graphs showing exactly when and where things went wrong – and what it did as reaction. This function aids faster recovery and fault-finding.

Scalable solution

The D1000 is usable as a stand-alone unit, but is also usable in larger installations.

Multiple D1000 unit can be linked together to form a larger system by connecting two "Link" wires between the units that must trip at the same time. This makes a string of identical units behave as a single unit, just with a larger number of inputs and outputs, which all behave in parallel.

Alternatively, the link feature can be used for RS485 MODBUS RTU communication e.g. for SCADA