KEY FEATURES 8000S HIGH POWER EARTH TESTING SYSTEM High power earth systems (Substations, Transmission towers, etc) have to be perioically monitore to check if they comply with safety levels establishe in stanars an regulations. This testing is critical, as the safety of the employees an neighbors epen on it. In orer to reuce the effects of noise (cause by inuction an unbalance loas) in these systems, conventional testing require high values of current injecte into the system. This not only compromises safety, but also means bulky, heavy an expensive equipment that is ifficult to carry an set up for fiel testing. Smaller & lighter than conventional methos, yet tough an urable Immune to system noise - Selectable testing frequency an precise filters eliminate noise an interference concerns. Live testing - Test can be mae with the substation in service. Easier testing - No network reconfiguration or protection equipment alterations require. Safer testing - Lower current values increases tests safety. Faster testing - Reuce testing times an testing costs to about 50% of high current methos. Inbuilt memory - Frequency selective multimeters store up to 7000 recors which can be later ownloae by USB to a computer. High accuracy - Measure complex impeances accurately an repetitively. STANDARDS COMPLIANCE Re Phase Instruments 8000S system, can be use to perform measurements inclue in international stanars such as: IEEE 80-2000; IEEE 81-1983; DIN VDE 0101; CENELEC HD637S1. Re Phase Instruments 8000S High power earth testing system was esigne to solve all the problems present in conventional testing methos. By generating a stable off-frequency current, that is very near but ifferent to the gri s frequency, an using precise filters to pick up the signal, we can test with no concern of the system s noise (funamental an harmonics won t affect the measurement). TEST CAPABILITIES Earth Impeance. Earth gri voltage rise. Step an touch voltages. Surface potential istribution. Soil resistivity. Earth continuity.
EARTH IMPEDANCE Earth impeance irectly refers to voltage rises in electrical systems uner fault. These voltage rises can be extremely angerous to utility an other personnel if they are over accepte safety levels. EARTH IMPEDANCE ARRAY Off frequency current is injecte into the earth either by an inepenent cable an stake or, where possible using an out of service overhea line. There are ifferent accepte methos to set up the current injection point an loop. The simplest metho is the linear metho, where the current stake is locate at a istance C=5D (5 times the Earthing gri longest measure, iagonal D). The reference (remote) potential point P, is locate between P=0.6C an P=0.65C (60% to 65% of the C s length). Earthing Gri D P C Current Stake Remote Potential Once the current loop an remote voltage are set up, injecting current at the chosen frequency into the system, an using the frequency selective multimeter, the impeance is automatically calculate. For more accurate results, the current loop an voltage reference can be configure in ifferent ways, an the impeance at the line s frequency can be calculate by interpolation of impeances at off-key frequencies. V0 STEP AND TOUCH VOLTAGES Vstep Vtouch Uner fault conitions, currents flowing through the earth gri cause voltage graients. Touch voltages refer to voltages that appear between han accessible points an the feet. Step voltages refer to voltages that appear between the feet while walking through the site. Both step an touch voltages shoul be monitore in orer to prevent possible electrocution. The same injection circuit use to calculate groun impeance can be use. The frequency selective multimeter shoul be set up for touch an step voltages by selecting the 1k resistance that simulates a person s internal resistance. Circular metal iscs of 8 cm raius are use to simulate the feet an hans an use to measure the voltage at ifferent points of the area searching for high risk areas. C STEP & TOUCH VOLTAGE ARRAY 1m 1m Earthing Gri D
SURFACE POTENTIAL DISTRIBUTION Surface Potential istribution is a key factor that conveniently shows the state of the grouning system. After measuring the voltages generate at equiistant points over the gri, graphs can be easily generate showing equipotential sections an further investigation can be one in high risk areas. SURFACE POTENTIAL DISTRIBUTION ARRAY The same injection circuit use to calculate groun impeance can use. An imaginary gri is lai over the substation or area an the frequency selective multimeter is connecte to measure the voltage ifference between the injection point an equiistant points over the gri. Y X Once all these points are surveye, results can be graphe an analyze. A goo performance grouning surface istribution curve shoul be relatively flat, usually with only a slight elevation at both ens. Curve 1 is an example of an even potential istribution. Curve 2 fluctuates an is an inication of a poor grouning system curve. SOIL RESISTIVITY v (mv) curve 1 curve 2 curve 3 (m) Even though most of Curve 3 has lower voltage ifference values than Curve 1, it shows a severe voltage peak, inicating a localize problem in the grouning gri. Grouning systems with curves like 2 or 3 nee further analysis to correct their problems an be mae safe. X As the impeance of an earth gri is influence by the resistivity of the soil where it lays, soil resistivity measurements are an important parameter when esigning earthing systems. SOIL RESISTIVITY ARRAY There are several possible connections. The Wenner array (shown in the rawing) is the simplest one. Current is injecte over the Current stakes an the frequency selective multimeter calculates the resistance (R) accoring to the appearing voltage between the potential stakes Resistivity is then easily calculate using the formula that suits the Wenner array: a/20 C1 P1 P2 a a a C2
. SYSTEM COMPOSITION.. MODEL 4024 INJECTION UNIT Switch moe voltage source generates stable signals at selecte frequencies. Currents at frequencies within the 45 to 65 Hz range can be generate, which will suit 50 or 60 Hz networks. This unit is connecte to moel 4023 (Coupling transformer) to increase the current signal by matching impeance. MODEL 4023 COUPLING TRANSFORMER Coupling transformer esigne to prouce maximum power output into a 1500VA loa. This transformer is riven by Moel 4024 (injection unit) at 180V which is connecte to the primary. The seconary is then connecte to the current loop to inject the current into the grouning gri. A selector switch is use for ifferent seconary taps to match current loop impeance. MODEL 4025D FREQUENCY SELECTIVE MULTIMETER Frequency selective ammeter an voltmeter, measures the magnitue an phase angles of signals in the selecte frequency (range 40 to 69 Hz) High quality filters allow use at frequencies up to a limit of 1 Hz ifference from the line frequency an still be immune to interference. Internal rechargeable battery allows for flexible fiel testing. Current inputs for Rogowski type 545 worm coil, LEM-flex Rr3020 AC or Fluke i300s flex current probe. Two 4025D are inclue in the stanar 8000S bunle to allow more efficient testing. OPTIONAL ACCESSORIES MODEL 4022B EARTH CONTINUITY TESTER Easily checks the continuity of connections within an earthing system. Compose by a base unit which contains the DC power supply an current source, an a remote unit which contains the hanhel meter an measurement probe. Remote unit has a fixe 5m lea that connects to the base unit an a 0.8 m lea to the probe hanle. A 100m extension reel allows speey testing over a 100m raius from the base unit. Rogowski coil Fluke i3000s Flex 24 100 m extension cable on a reel Type 545 worm current input current probe for remote unit of 4022B earth 3 m long with interface unit. continuity tester.
Subject to change without notice TECHNICAL DATASHEET RED PHASE INSTRUMENTS has been proviing instrument an testing solutions for the worlwie electric power inustry for more than 35 years. From our heaquarters in Melbourne, Australia, we esign an manufacture state of the art equipment that often no other company makes. We also manufacture an service oler an more mature proucts that are still in eman. Our customers vary from the very largest national utilities to small pacific islan cooperatives with only 10MW capacity. No matter who our customers are, we plan to give them excellent service an proucts helping them to achieve the maximum result at a reasonable price. Re Phase Instruments Pty Lt. 10 Ceylon St, Nunawaing (3131), Melbourne, VIC, Australia. sales@rephase.com.au www.rephase.com.au Distribute By: