At locations involving the generation, distribution and consumption of electrical energy, certain safety measures must be met in order to protect human life. In many cases, these safety measures are national and international regulations which must be checked regularly. Grounding, the connection of exposed conductive parts to the earth in case of a fault, represents the most fundamental safety measure. There are requirements for grounding of transformers, high and medium voltage power pylons, railway tracks, tanks, vats, foundations and lightning protection systems.
The effectiveness of grounding systems should be checked using a ground test instruments such as the 1625 which checks the effectiveness of connections to the ground. The 1625 provides the perfect solution by combining the latest technology into a compact, field-rugged and extremely easy to use instrument. In addition to performing standard 3- and 4-pole ground resistance measurements, an innovative process accurately measures individual earth electrode resistances in single and meshed earthed systems without disconnecting any parallel electrodes. One specific application of this capability is quick and accurate measurement of power pylon grounds.
The 1625 also incorporates automatic frequency control (AFC) to minimize interference. Before measuring, the instrument identifies existing interference and selects a measurement frequency to minimise its effect. The 1625 incorporates microprocessor controlled automatic measurements including checking probe hookup to ensure that measurements are taken correctly. It measures all probe ground resistances to ensure reliable, repeatable results. Probe resistance and auxiliary earth resistance are also measured and displayed.
- Measurement of interference voltage (UST)
- Measurement of interference frequency (FST)
- Measurement of probe resistance (RS)
- Measurement of auxiliary earth electrode resistance (RH)
- Measurement of earthing resistance 3pole, 4pole, (RE) with or without using the external clip-on current transformer for selective measurement of single earthing branches in mesh operated earthing systems A
- Resistance measurement 2pole with AC voltage (R~) • Resistance measurement with DC voltage 2pole, 4pole, (RF)
The instrument is made up of two parts: 1. The base part which contains the measuring electronics. 2. The protective housing. The functions are selected with the central rotary switch. Four rubber buttons, which start measurements, read out supplementary measuring values and select special functions, are located on the left hand side of the front panel. This design enables quick and clear one-hand operation. The measured values are displayed on a liquid crystal display with correct decimal point and unit. Various additional special characters indicate measuring mode, operating condition and error messages. The auxiliary power supply consists of 6 x 1.5 V batteries (IEC R6 or LR6 or type AA). This device has been developed, designed and manufactured in compliance with quality system DIN ISO 9001.
Operation: Central rotary switch and function keys Working temperature range: -10 °C … +50 °C
Operating temperature range: 0 °C … +35 °C Nominal temperature range: 18 °C … +28 °C Storage temperature range: -30 °C … +60 °C
Battery life span: with IEC LR6/type AA: typ. 3000
Measurements: (RE+RH ≤ 1 kΩ) with IEC LR6/type AA : typ. 6000
Measurements: (RE + RH >10 kΩ) Dimensions: 240 mm (W) x 220 mm (D) x 90 mm ( H )
Weight: ≤ 1.1 kg without accessories ≤ 5.5 kg incl. accessories and batteries in carrying case Case material: NORYL, shock -and scratch proof Thermoplast.