Cybertronix Sentinel EFI-BFZ User manual

Sentinel™ EFI-BFZ
EARTH FAULT INDICATOR
USER’S MANUAL
Tel: [phone] Email: [e-mail]
3 Glenart Road, Kloof 3610, South Africa www.cybertronix.co.za
Ver. 3.2

Sentinel™ EFI-BFZ User’s Manual
Version 3.2 Page 2 of 15
CONTENTS
1. safety notice.....................................................................................................................................3
2. overview...........................................................................................................................................4
3. FEATURES .........................................................................................................................................4
4. INSTALLATION ..................................................................................................................................4
4.1 CURRENT SENSOR ......................................................................................................................4
4.1.1 Multi-core cable system......................................................................................................5
4.1.2 single-core cable system .....................................................................................................7
4.2 INDICATING UNIT .......................................................................................................................7
4.3 Remote INDICATOR....................................................................................................................7
4.3 Remote indicator .......................................................................................................................8
5. OperatioN.........................................................................................................................................8
5.1 current sensor ............................................................................................................................8
5.2 Indicating unit ............................................................................................................................8
5.2.1 Auxiliary RELAY (Optional) ..................................................................................................9
5.2.2 remote indicatOR (Optional)...............................................................................................9
5.2.3 MANUAL TEST and reset.....................................................................................................9
5.2.4 Battery supply .....................................................................................................................9
6. TESTING..........................................................................................................................................10
7. SPECIFICATIONS .............................................................................................................................11
8. ORDERING ......................................................................................................................................13
9. warranty.........................................................................................................................................15

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Version 3.2 Page 3 of 15
1. SAFETY NOTICE
Review the following safety precautions to avoid serious injury or death and to prevent damage to
this product or any products connected to it. To avoid potential hazards, use this product only as
specified. This equipment contains high voltages. Electrical shock can cause serious or fatal injury.
PRECAUTIONS
WARNING: Under certain fault conditions, high voltages can be conducted into the
earth fault indicator enclosure through the CT, remote indicator, or the auxiliary relay cables.
All parts within the enclosure should be handled as if carrying dangerous voltages.
WARNING: Use extreme caution during the installation and use of the earth fault
indicator as high voltages and currents may be present in the circuit.
•Ensure that the current sensor is installed at earth potential on the HV cable system.
•Ensure that the current sensor is installed on the screened part of the cable system.
•Use caution during the installation and use of this product; high voltages and currents
may be present in the circuit.
•This product must be used only by qualified personnel practicing applicable safety
precautions.
•Wear protective clothing and gloves as required.
•Do not install this product on live conductors.
•Always de-energize circuit before installing the current sensor and indicating unit.
•Always inspect the current sensor, indicating unit and all leads for damage before using
the product.
•Do not use the product if damaged.
!

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2. OVERVIEW
The Sentinel™ EFI-BFZ-50 is one of a family of Earth Fault Indicator (EFI) products that is designed
to assist in the rapid location and isolation of earth faults on high voltage cable networks. The EFI
can be used in radial networks or in openly operated ringed networks. When an asymmetrical
current greater than 50A in a 3-phase cable system is detected an earth fault is indicated by means
of a electromechanical flag indicator. The path of the fault current from the feeding point to the
fault location is marked by the triggered EFI’s. The defective conductor segment is located between
the last EFI which has been triggered and the first EFI which is still inactive.
3. FEATURES
• Battery powered
• Electromechanical flag
• Auxiliary relay output contact
• Remote indication driver
• Split-core current sensor
• 50A nominal trip
• 50ms minimum fault duration
• Manual test and reset facility
• IP65 environment protection
• Rugged and reliable electronics
• ISO9001:2000 based quality assurance
• Electromagnetic compatibility
4. INSTALLATION
4.1 CURRENT SENSOR
The Sentinel™ current sensor consists of a flexible steel core which is wrapped around the three-
phase system to be monitored and fastened tightly in place with adjustable cable-ties. The current
sensor is normally shipped fastened in a closed position. The cable-ties are released by depressing
the small ratchet on the head while bending back the tail. The current sensor should not encircle
the cable earthing as well. Instead, the cable earthing should bypass the current sensor.
The current sensor is available in three different sizes depending on whether it is to be applied to
an installation consisting of a multi-core cable or a system comprising of three single-core cables.

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4.1.1 MULTI-CORE CABLE SYSTEM
The Sentinel™ EFI ships with a standard sized (CT100) current sensor, which is suitable for most
multi-core cable systems. A larger current sensor (CT150) is also available but must be specified at
time of order. The flexible sensor core is mounted on the screened part of the cable, below the
stripback point. The core is wrapped around the cable and the cable-tie is pulled tight as far as it will
go. A second cable-tie is used to hold the core firmly onto the cable. The cable screen is turned back
underneath the core and then terminated to earth as shown in the Figure 1.

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Version 3.2 Page 6 of 15
EARTH
CURRENT
SENSOR
FIGURE 1: CURRENT SENSOR MOUNTED ON MULTI-CORE CABLE SYSTEM
OUTGOING CABLE
TERMINATION
CURRENT
SENSOR
L1 L2 L3
EQUIVALENT CIRCUIT
SCREEN
CURRENT
SENSOR
(CT300)
EARTH
FIGURE 2: CURRENT SENSOR MOUNTED ON SINGLE-CORE CABLE SYSTEM
OUTGOING CABLE
TERMINATION
CURRENT
SENSOR
L1 L2 L3
EQUIVALENT CIRCUIT
SCREEN

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Version 3.2 Page 7 of 15
4.1.2 SINGLE-CORE CABLE SYSTEM
A larger current sensor (CT300) is available for application on single core cable systems. These
systems usually consist of three single-core cables spaced in a row, side-by-side. The flexible sensor
core is wrapped tightly around all three cables forming a rectangular oval, and fastened in place
with cable-ties. Care should be taken to ensure that the core is mounted on the screened part of
the cable. The screen of all three conductors should be turned back underneath the core and then
terminated to earth as shown in Figure 2.
4.2 INDICATING UNIT
The Sentinel™ indicating unit is normally flush mounted onto a vertical surface. When the cover is
removed, mounting holes are exposed for use in bolting the indicating unit to a surface. The current
sensor and other accessories are electrically connected to the indicating unit by feeding the leads
through cable glands (PG7) on the indicating unit and connecting them to two-way screw terminals
mounted inside the indicating unit enclosure. With the cover and cable glands tightened firmly the
enclosure provides IP65 protection.
FIGURE 3: INDICATING UNIT SHOWING TERMINALS AND MOUNTING HOLES
Test /
115mm
65mm
Enclosure
lid
Flag indicator
Mounting
holes
Battery
Remote
indicator
terminal
Auxiliary
relay
terminal
CT terminal
Test/Reset
pushbutton
Reset timer
setting

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REMOTE INDICATOR
A remote indicator can be ordered separately or ordered pre-installed. The remote indicator is
designed to be mounted through a hole in the switchgear enclosure so that it is visible from the
outside.
5. OPERATION
5.1 CURRENT SENSOR
The Sentinel™ current sensor comprises of a flexible iron-core belt with a pickup coil. The belt is
fitted around the three-phase cable system being monitored and works on the core-balance current
sensing method. Under normal conditions the magnetic flux from the three phase currents
summates to zero and the pickup coil generates no voltage output. When an earth fault occurs the
summation flux is non-zero and a voltage proportional to the magnitude of the earth fault is
generated. The indicator unit is programmed to trip for a nominal earth fault of 50 A. The current
sensor has no exposed metal parts and is completely encapsulated and corrosion proof.
5.2 INDICATING UNIT
The primary indication on the EFI-BFZ-50 is a light-emitting-diode (LED). The LED will flash at
approximately 1Hz when the EFI is in a tripped state and remain extinguished when the EFI is in a
reset state.
FIGURE 4: REMOTE INDICATOR
FRONT VIEW
SIDE VIEW
Ø M12
50mm

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The indicating unit continuously monitors the output signal from the current sensor. The current
sensor transmits a voltage which is proportional to the measured current. For primary currents in
excess of 50A the current sensor saturates and a limiting circuit inside the indicating unit clamps
the output voltage to below 10V even for high fault currents.
When an imbalance is detected, onboard circuitry analyses the fault current. The magnitude and
duration of the half cycles of fault current are measured. Current spikes and glitches are ignored. As
soon as valid fault current has been detected, the Sentinel™ triggers and enters a tripped state.
The indicating unit is powered from a long-life lithium battery. The unit will reset from an on-board
timer after 4 hours or 8 hours (selectable via jumper) of LED flashing.
5.2.1 AUXILIARY RELAY (OPTIONAL)
An on-board auxiliary relay provides a potential-free, normally-open contact for additional signaling.
A 2-way screw terminal is provided on-board to which the user can connect a signaling cable. A reset
will latch the relay into the reset position (open). A tripped state will latch the relay into a tripped
position (closed).
5.2.2 REMOTE INDICATOR (OPTIONAL)
An optional remote indicator can be ordered pre-installed or ordered separately. A 2-way screw
terminal is provided on-board for connection of the remote indicator. It provides flashing LED
indication at some distance from the main indicating unit. During a tripped state the unit will flash
at a rate of about 1Hz. The remote indicator is weather-proof and is housed inside a stainless steel
bolt which also makes it vandal-proof.
5.2.3 MANUAL TEST AND RESET
A magnetic reed switch on-board allows the unit to be manually tested. The switch can be activated
externally with a small, strong magnet, without opening the enclosure. The reed switch is located
on the right-hand side of the unit. The test feature can also be activated manually via a push-button
located on the printed circuit board inside the enclosure. The manual test feature can both trip and
reset the EFI, as well as test the battery. After being manually tripped the unit will automatically
reset after 60 seconds to prevent inadvertant wastage of the battery.
5.2.4 BATTERY SUPPLY
The Sentinel™ EFI-BFZ-50 is powered by a replaceable, long-life, ½AA, 3.6V lithium battery. The
battery has a shelf-life which easily exceeds 10 years. During normal operation the quiescent current
if the device is so low that it approaches the self-discharge rate of the battery. Significant current is
only consumed when the device trips for an earth fault. Even then the power consumption is very
economical and the device yields more than 1000 flashing hours. The state of the battery can easily
be checked by manually testing the unit. If the battery is still healthy then the device will initially
flash rapidly (10 Hz) for a couple of seconds and then commence to flash at its normal rate (1 Hz). If
the battery requires replacement then on activation of the test facility, the indicating unit will only
flash at its normal indication rate (1 Hz) or not at all. The device is protected against battery reverse
polarity.

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Complete battery technical details are provided below.
Battery type: 3.6V Lithium, size ½AA
Specification: Model TL-2150/S or similar
International size refs: ½AA, 1/2R6, 1/2UM-3
Capacity: 850 mAH
Open circuit voltage: 3.7 V
Quiescent drain current: <5 µA
Flashing drain current: <0.8 mA
Minimum operation life: >1000 flashing hours
Temperature effects: no adverse effects -55° C to +85° C
Shelf-life: >10 years
Manufacturers: TADIRAN
Manufacturer’s reference: 74/02778/07
Supplier: Arrow Altech
Alternate Manufacturer: SAFT
Alternate Supplier: Battery Terminal
6. TESTING
The Sentinel™ EFI can be fully tested by injecting test current though the current sensor. A test
procedure is suggested below.
1. Inject 40 A for 1 second. The device should not trip.
2. Inject 60 A for at least 50 ms. The device should trip.
The device will reset after 4 hours or 8 hours (selectable) or can be manually reset.

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7. SPECIFICATIONS
Network voltage range: 1-36kV
Trip current: 50A ±10A
Minimum fault duration: 2.5 cycles (50ms @ 50Hz / 40ms @ 60Hz)
Fault current withstand: 25kA for 1s
Primary indication: LED, flash rate 1Hz nominal
Timer reset: 4 or 8 hours selectable
Manual test: Magnetic swipe alternately initiates trip and reset
Operating temperature: -20ºC to 70ºC
Enclosure
-dimensions 115mm × 65mm × 40m
-material ABS, grey
-mounting Flush-mounting, two M4 holes
-degree of protection IP65
-cable gland size: PG7; cable diameter range 3-6.5mm
-mass: 250g
Current sensor
-CT100 (standard size): 100mm diameter
-CT150 (optional): 150mm diameter
-CT300 (optional): 300mm × 100mm rectangular oval
-material: Insulated silicon steel
-mounting: releasable cable-ties
-lead length: 3m
-lead type: 2-core, 0.5mm2, doubly insulated
-mass: 250g
Auxiliary relay
-type: Latching, N/O on reset
-rating: 220Vdc, 250Vac, 2A
Remote indicator
-dimensions: M12 Hex Bolt 50mm long (200g)
-material: Stainless steel
-mounting: Self-mounting through single M12 Hole
-lead length: 2m
-lead type: 2-core, 0.5mm2, doubly insulated
-degree of protection IP65
-indication method LED, flash rate 1Hz nominal

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Battery
-type: 3.6 V, ½AA, lithium battery
-capacity: 0.85AH
-quiescent current: <5 µA
-flashing current: <0.8 mA
-shelf life: >10 years
-flashing life: >1000 flashing hours (>500 hours with remote indicator)

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8. ORDERING
Table 1 below shows the codes to be used for product ordering. Only the first three code groups
need to be specified for the standard versions of the product. The standard versions ships without
the items from groups 4, 5 and 6, and with a standard size current transformer (CT100 with 3m
lead).
Group 1
Product Range
EFI
Earth Fault Indicator
Group 2
Symbol 1: Power source
M
Mains powered
B
Battery powered
C
CT powered
Symbol 2: Indicator type
L
LED
F
Flag
Symbol 3: Glands
Z
Cable glands fitted
Group 3
Nominal trip current in amps
50
50 amps trip level
Group 4
Symbol 1: Mains cable fitted
M
Mains cable
Symbol 2: Mains cable length in meters
3
3 meters
Group 5
Symbol 1: Remote indicator fitted
R
Remote indicator
Symbol 2: Remote cable length in meters
3
3 meters
Group 6
Symbol 1: Auxiliary relay fitted
A
Auxiliary relay
Symbol 2: Auxiliary cable length in meters
2
2 meters
Group 7
Symbol 1-5: Current transformer diameter
CT100
100mm diameter
CT150
150mm diameter
CT300
300mm by 100mm
Group 8
Symbol 1: CT fitted
C
Current Sensor
Symbol 2: CT cable length in meters
3
3 meters
TABLE 1: ORDERING CODES

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For Example:
ORDERING CODE
DESCRIPTION
EFI-BFZ-50 (standard version)
- Battery powered
- LED indication
- 50A trip
- CT diameter 100mm, 3m lead
EFI-BFZ-50-M5-R7-A2-CT150-C3
- Battery powered
- LED indication
- 50A trip
- Mains cable, 5m lead
- Remote indicator, 7m lead
- Auxiliary relay, 2m lead
- CT diameter 150mm, 3m lead
NOTE:
• The mains lead is an optional component and must be specified if required.
• The remote indicator is an optional component and must be specified if required.
• The auxiliary relay is an optional component and must be specified if required.
• The unused cable-glands ship with a rubber stopper inserted to maintain sealing integrity.
• The EFI unit ships in a brown corrugated cardboard box.

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9. WARRANTY
The Sentinel earth fault indicator electronic hardware and software is copyright Cybertronix cc
1996.
This product is warranted to be free from defects in material and workmanship for a period of
twelve months (12) from the date of shipment. Correction shall be in the form of repair or
replacement of the defective items or components, freight paid by the customer both ways. Such
correction shall constitute a fulfillment of all Cybertronix cc liabilities in respect to said items and
components. In no event shall Cybertronix be liable for consequential damage.
No other warranties:
To the maximum extent permitted by applicable law, Cybertronix cc disclaims all other warranties,
either express or implied, including but not limited to implied warranties of merchantability and
fitness for a particular purpose, with respect to the Sentinel product and accompanying product
manual. Cybertronix cc makes no representation or warranty that the product is 'error free', or
meets any user's particular standards, requirements or needs.
Disclaimer :
To the maximum extent permitted by the applicable law, in no event shall Cybertronix cc be liable
to the user for any special, indirect, consequential or similar damages, including any lost profits or
lost data arising out of the use or inability to use the product or documentation or any other data
supplied therewith even if the seller or anyone else has been advised of the possibility of such
damages, or for any claim by any other party. In the event of the above limitation not applying to
the user, then in no case shall the Cybertronix cc liability exceed the original purchase price of the
product.