Red Phase Instruments - Design & Manufacture Electrical Test Equipment
Red Phase Instruments - Design & Manufacture Electrical Test Equipment


Our Earth Testing equipment is widely used to determine earth grid integrity and potential contour measurements in large grounding systems such as critical utility, telecommunications and industrial assets.

Measurements commonly performed with our equipment are:
- Step & Touch Potential and Current split / branch measurements
- Soil Resistivity
- Grounding system impedance
- Continuity / remote bonding resistance
- Lightning impulse impedance testing

Lightning Impedance Tester: MODEL 4051     
4051The 4051 lightning impulse impedance tester is used to inject a simulated
lightning impulse signal at up to 30 Amps between two electrodes such as
a Pylon footing and a remote test electrode.

A measurement of the ground impedance between between the two is
determined automatically and if the operator so chooses they may also
perform a further test to determine how the same impulse can affect the
potential of a nearby metallic object within the impulse path.

Two tests are available:
- Direct Impedance test
- Electrode Impedance test

These tests may be performed with one or both of the impulse wave shapes below:
8 / 20uS
10 / 350uS
More impulse shapes are available upon request, (contact RPI), however the two outlined above
have been found to give the most practical and consistently reliable results.
Continuity Tester: MODEL ECT-4                              
MODEL ECT-4 CONTINUITY TESTERThe ECT-4 is a 4 wire Kelvin micro-ohm meter used to check the
electrical quality of metallic structures and their connection integrity
to other bonded structures in grids and electrical systems such as a
sub-station or transmission station.

A custom back pack carry case houses a power source which injects
discrete levels of current at 1, 2 or 3 Amps directly between two points
in the grid connected network.

The ECT-4 and it's extension reel accessories allow this test to be
performed over small or large distances using a single Earth reference.

The ECT-4 has filtering for excellent 50Hz and 60Hz rejection and also
features 5 current direction modes to further mitigate DC offset and

The 5 current direction modes are:
- Forward
- Reverse
- Pulsed Forward
- Pulsed Reverse
- Pulsed Bipolar

Measurements are taken with a moulded hand probe which includes twisting retractable brass pins
used to make the surface connection with a bonded metallic object.

The hand probe has a 5cm backlit LCD which displays the results of the bond down to a 10u resolution.
The injection mode described above and current range can also be selected on the hand probe via three
tactile push buttons.

The ECT-4 runs off a separate battery, also housed in the back pack, giving the operator single handed
operation and superior mobility while performing continuity tests for over 5 hours.

The ECT-4 comes with all accessories necessary to begin testing straight out of the box.

Please download our data sheet for more information.
2kVA Current Injection Unit: MODEL 4046      
MODEL 4046 INJECTION UNITThe Model 4046 is a frequency adjustable switch mode
current injection source that is used to drive the primary of
a multi tapped coupling transformer to induce variable
voltage and current magnitudes into an earth or passive
load loop at maximum power continuously if required.

Typically the earth test loop / circuit consists of the earth grid
under test connected to a remote earth grid through an earth
path in the ground. To complete the loop, a return connecting
path isolated from earth, usually an 'out of service' feeder or
separate injection line is also used. The test current is driven
around the loop by the secondary winding of the Model 4047C
Coupling Transformer which is inserted into the loop.

Frequencies from 40Hz to 70Hz can be selectively generated
by the 4046 to avoid interference with background line
frequency. Voltage drops generated by the injected current
around the earth loop are measured with a frequency
selective multimeter fixed to the current injection test

Measureable results over the test landscape can be profiled with the 4025E or 4031 frequency selective
multimeter. Both the 4025E or 4031 and the 4046 Injection system have a GPS function which is used
for position location and phase synchronization which frees up the need for phase reference cabling
during current split measurements and also provides relative positioning information so that the operator
may choose the best line of potential measurement during EPR tests to avoid mutual coupling/induction.


The 4047/C is a 2kVA rated coupling transformer with eight
individual tap settings covering an impedance range from
5 to 400 Ohms.
Used in conjunction with the Model 4046 the tap selection must also be reflected in the tap menu settings of the Injection Unit which also drives the coupling transformer.

When the correct tap is chosen the Amplifier will see a large reflected load and it will be able to deliver maximum power.

The unit also comes with all necessary current, voltage and
load sensing circuitry along with 2 fans and a thermal cut-out switch for safe operation over wide temperatures.


8kVA Current Injection Unit: MODEL 4041      
MODEL 4041 INJECTION UNITThe Model 4041 is the largest of our switch mode current injection sources used for injection based testing. 

This 3 phase unit works on the identical principle of operation
as our 2kVA system, however the 4041 in conjunction with
the 4042 coupling transformer have been specifically
designed to perform current injection tasks over very long
haul and demanding environments continuously at maximum

With our 4025E or 4031 frequency selective multimeters,
terrestrial voltage profiling is made easy with GPS positional
information available on both the 4041 and 4025E/4031 units.

Another advantage of this is the ability for the two units to
synchronize phase readings, thus reducing the cabling
required when performing current split or branch
measurements and it also provides relative positioning
information so that the operator may choose the best line
of potential measurement during EPR tests to avoid
mutual coupling or induction.

MODEL 4042 COUPLING TRANSFORMERModel 4042 is our largest coupling transformer, with eight
secondary taps rated to 8kVA.
The 8 taps on the 4042 allows the user to adjust the injection
voltage and current to a desired value via individual tap
settings whose impedance ranges from 1 to 80 Ohms.

When the correct tap is chosen and the tap menu settings
on the injection unit is set to the same value, the amplifier
will see a large reflected load and will deliver maximum
power through this tap to drive current around the earth loop.

As with the lower power units, the primary of the coupling
transformer is driven by the Model 4041 injection unit up to
a nominal 320V. The various secondary taps on the 4042
translate the input from the injection unit to an output
voltage range from 90V to 800V.
Each tap on the coupling transformer is connected to a
feedback circuit which constantly senses the earth loop's voltage and current / load.
The injection unit uses this data to maintain a constant injection current at maximum power.

The 4042/3 also comes with cooling fans and a thermal cut out switch for safe operation.
Frequency Selective Multimeter: MODEL 4031  
MODEL 4031 FREQUENCY SELECTIVE MULTIMETER MODEL 4031 FREQUENCY SELECTIVE MULTIMETER When performing earthing/grounding system tests it is essential to filter out the predominant 50 or 60Hz currents that are often present in a typical test situation.
This is done by injecting at frequencies other than 50 or 60Hz
and making sure that the instrument which detects voltages and
currents around the loop is tightly tuned to the same frequency.

The 4031 is a hand held frequency selective ammeter and voltmeter used to measure the I/V magnitudes and
phase of signals induced into an earth loop via a
high power current injection system such as the
Model 4041 and 4046.
The voltmeter part of the 4031 allows, fall of potential and step & touch voltages
to be measured easily and accurately, which is important for the safety of both
the general public and utility personnel.
In earth loops, measurements are made of voltage, current and phase angles
enabling the impedance of the circuit to be calculated by the software.

The 4031 runs off an internal rechargeable Li-ion battery which lasts 5 to 6 hours.

The 4031 comes in two variations. A Rogowski coil type or a LEM~flex RR3020 AC current probe type, but not both. The Rogowski coil and LEM current probe are available as optional accessories.

The 4031 also has an on board GPS feature which is used for cable-less phase synchronization when performing current branch measurements.

The 4031 Multimeter operates in the 40 - 69 Hz range, rejecting both 50 Hz or 60 Hz power frequencies.
The high quality of the Multimeter’s filters allows it to be used at frequency resolutions to 0.1Hz deviation
from the baseline power frequency with no interference.


Frequency Selective Multimeter: MODEL 4025E   
MODEL 4025E FREQUENCY SELECTIVE MULTIMETERThe 4025E is the latest revision in our 4025 series of frequency selective
multi-meters. It maintains all of the features of the previous models for
measuring the I/V magnitudes and phase of signals induced into an earth
loop via high power current injection.

The 4025E has been designed with better step resolution allowing for
measurement of injection frequencies to 0.1 Hz off main line frequency
without interference.
Designed to be used with our new GPS based injection products, it takes
full advantage of the GPS features to synchronize with the injection system and provide the operator with cable free current phase referencing and a visual display of the operator's relative position to the other injection points
during large earth system potential measurements.

The 4025E runs off an internal rechargeable battery with a
7 to 8 hour field time before requiring re-charge.