TOMORROW'S TECHNOLOGY TODAY
GROUSER
Earth Fault Locator for DC Systems
Ideal for precise location of high resistance faults
on floating DC systems
Features
• Locates Earth faults on live DC circuits
• Sensitive to faults as high as 68k ohm
• Does not affect system integrity
• Traces and locates multiple faults on systems
• Unaffected by load current or ripple
• Easy to use, battery powered
• Can be tuned to the fault current only
• Works on live systems up to 300 volt
• Locates faults in machine windings
• Traces earth faults on thermocouples
The Grouser is an easy to use Earth fault locator that was designed to operate on live, floating DC systems with voltages up to 300 volt DC.
Grouser will not interfere with sensitive equipment connected to the DC system and is unaffected by ripple, or switching transients.
Operation
The Grouser Transmitter is connected between the DC circuit and earth, if a fault or multiple faults are present a low frequency current will flow between the transmitter through the circuit to the fault and then back via the earth forming a current loop.
The Grouser receiver can then trace the low frequency signal by use of the special search coils (3 sizes are provided) with pin point accuracy to the earth fault or faults.
Grouser Transmitter
Battery powered transmitter outputs 9 volt RMS open circuit, 50mA short circuit. The output frequency is pre-set at between 11.0 Hz and 12.0 Hz and factory matched to the receiver frequency.
The unit can operate on live circuits up to 300 volt DC, it is fuse protected and has semi rotary controls to prevent accidental operation.
A LED gives indication of battery condition and on / off status.
Grouser Receiver
The receiver is battery powered, it has a large, easy to read analogue indicator and rotary gain control mounted on the front panel.
The frequency range is factory set between 11.2 and 11.8 Hz, this low, very precise frequency enables the Grouser to operate with a clean signal even in “noisy” conditions. There is also a 10 turn capacitive balance control that enables the operator to cancel out capacitive signals and view the fault signal independent of other factors.
Inductive Sensing Heads
The search coils are made of a special magnetic alloy, laminated and epoxy resin sealed, wound with robust insulated copper wire and encapsulated.
Four different sizes are available from 6mm, 30mm and 45mm, these are supplied as standard. A 55mm and 95mmhead are available as an optional extra.
The Grouser is supplied in a heavy duty leather case carry case with connection cables, clips and a comprehensive operation manual.
The principle of operation is straight forward, inject a small current at a specific frequency, trace only the current flow at that specific frequency, where the current flows to earth is where the fault or faults are.
In practice this is more complex than it would first appear, Grouser has overcome problems such as spillover, inductive coupling, interference, capacitive coupling, spurious noise, etc. etc.
The Grouser has had 20 years of continuous development, to refine this instrument to an easy to use practical tool, most importantly..........
It works !
Technical Details
TRANSMITTER - STANDARD MODEL
Frequency
Waveform
Open circuit voltage
Short circuit current
Dimensions
Weight
Max voltage to be imposed-on Tx
Output fuse
Batteries
Battery current
Controls
Terminals
Preset in range 11.0 – 12.0 Hz
Sinusoidal
8.5 - 9.0 v r.m.s.
55-65 mA subject to change
240 x 160 x 90 mm. ABS case
3.0 kg inc. 4 x PP9 batteries
300V DC of either polarity, (auto - correcting ). No A.C. from system
250mA quick blow 5 x 20 mm
4x PP9 ( IEC equiv. 6F100) or Equiv
30mA av. varies with fault severity
One, Semi-rotary ON - OFF switch
2 x 4mm shrouded safety sockets and
1 x 4mm transformer accessory skt.
RECEIVER
Frequency
Sensitivity
Capacitive balance
Dimensions
Batteries
Weight
Controls
Terminals
Max Voltage to REF Sockets
Fixed in range 11.2 - 11.8 Hz
O.125mA for mid-scale meter indication = 68k ohm fault
0.22 - 30 Uf range
190 x 110 x 60 mm excluding knobs and handle
2 x MN1604 or 6LF22 equiv.
1.25 kg inc batteries
Semi-rotary ON-OFF switch
10 Turn Balance potentiometer Gain control
Input, standard 6.3 mm jack skt 2x4 mm shrouded REF socket
300V DC
Grouser is the property of GFAL Limited
FLOAT POWER SYSTEMS & CONTROLS © 2010
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