MODEL 4022B Remote Bonding Tester              

The Model 4022B is used to check the continuity of
connections within an earthing system over very large
distances, generally in substations, terminal stations and power plants. The small carry case houses a mains powered injection system which injects a measureable current directly into an earthing grid.
The actual resistance is measured on a handheld readout which is on the end of a test lead.
We can supply extension cables up to 100M on a drum so that the resistance can be measured over a long earthing structure.
 

The Model 4024B is a frequency tuneable, adjustable 1.5kVA power source that is used in conjunction with the Model 4023 Coupling Transformer to induce either a high current and low voltage, or high voltage and low current, into an earth loop under investigation.

Frequencies from 45Hz to 65Hz can be generated and the voltage drops around the earth loop are measured with the tuneable 4025D frequency selective multimeter which is tuned to the injection frequency set by the 4024B.

In most cases a large current is injected into the earth loop under test via the multi-tapped coupling transformer, (the 4023) so that
the 4025D receives the best possible signal.

In practice the 4023 essentially couples power from the
1.5kVA injection unit into the earth grid.
To overcome most soil resistivity types the 4023 allows the user to adjust the injection voltage and current via selectable tap settings from 0.5 Ohms to 40 Ohms. The earth test current is then driven around the earth loop by the secondary winding of the 4023.

The primary of the coupling transformer is driven by the
Model 4024B Injection Unit. Inside the 4023 various secondary taps are brought out to terminals on the front panel via the selector switch.
When the correct tap is chosen the Amplifier will see a reflected 1500VA load and it will deliver maximum power
if so chosen.

As with the 4024B, the Model 4046 is also a frequency
tuneable switch mode voltage and current 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.

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, is
also used. The test current is driven around the loop by the
secondary winding of the Model 4047 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 tuneable multimeter fixed to the injection test frequency.

Measureable results over the test landscape can now be profiled with the soon to be released 4025E tuneable multimeter. Both the 4025E and the 4046 Injection system have a GPS function which is used for position location and phase synchronization which frees up cabling during current split measurements.

The 4047/C is a larger 2kVA rated coupling transformer with
an equal number but different value tap settings than the
older 4023.

The user is able to manually adjust the injection voltage and
current with the tap settings whose impedance ranges from
5 to 400 Ohms.
This must also be reflected in the tap menu settings of the
4046 Injection Unit for proper results.

As with the 1.5kVA system the primary of the coupling
transformer is driven by the Model 4046 Injection Unit.

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

The Model 4041 is the largest of our switch mode voltage and current sources used for injection based testing. 

This 3 phase unit works on the identical principle of operation as our 1.5 and 2kVA systems, however the 4041 in conjunction with the 4042 coupling transformer have been specifically designed to perform injection tasks over very long haul, harsh and dry environments.

With our soon to be released 4025E tuneable multimeter, soil and ground profiling will be easier with GPS positional information available on both units.
Another advantage of this is the ability for the units to synchronize phase readings, thus reducing the cabling required when performing current split or branching measurements.
earth loop are measured with a tuneable multimeter fixed to the injection test frequency.

Model 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 selectable tap
settings whose impedance ranges from 5 to 400 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. Inside the 4042, various secondary taps are
fed back to current and load sense circuitry.
These circuits monitor the load and impedance conditions
constantly and reflect all status information back to the
Injection unit.

The 4042 also comes with cooling fans and a thermal cut out
switches for safe operation.

MODEL 4025D Tuneable Multimeter                     

This is the latest version of our 4025 series of frequency selective multimeters. In earth testing it is essential to filter out the predominant 50Hz currents that are often present in a typical test situation. This is done by injecting at frequencies other than 50Hz, and making sure the instrument that detects voltages and currents around the loop is tightly tuned to the same frequency.

The 4025D is a frequency selective ammeter and voltmeter used to measure the magnitude and phase of signals produced by the Model 4024B Injection Unit.
The voltmeter part of the 4025D 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 angle enabling the impedance of the circuit to be calculated by the software.

The 4025D can be mains powered or run off an internal rechargeable battery.

The current input is specifically for use with a Type 545 worm ( Rogowski ) coil or a LEM~flex RR3020 AC current probe . The Rogowski coil and LEM current probe are available as optional accessories.
The Rogowski coil accessory is a very convenient current measuring device, which can simply be wrapped around current carrying structures. The ability to measure currents in various structures is important in tracking earth currents during investigations. Utility engineers need an accurate picture of the earth currents flowing in substations, power stations and similar large installations when designing protection systems.

The 4025D 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 frequencies up to a limit of 1Hz from the power frequency and still reject power frequency interference.