This document provides information about an Earth Loop Voltage Detector (ELVD) with a circuit breaker developed by Dolphin Safety Devices. The 3 sentence summary is: The ELVD is designed to instantly disconnect power to faulty appliances within 10 milliseconds if the voltage between the neutral and earth terminals exceeds 70V, preventing electric shocks. It addresses limitations of Earth Leakage Circuit Breakers (ELCBs) that can cause whole installations to lose power or require secondary paths for humans. Test results and specifications are presented to demonstrate that the ELVD can effectively enhance safety compared to other methods.

1. Welcome to the Technical
Presentation of
Shock Preventer
BY
DOLPHIN SAFETY DEVICES
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2. EARTH LOOP VOLTAGE DETECTOR
WITH CIRCUIT BREAKER
(ELVD)
• NO JOLT FROM VOLT.
• PREVENTION IS BETTER THAN CURE.

3. At present
• To prevent electrical shock three wire system with protective
multiple earthing is being used with rewirable / HRC fuse.
• To enhance the effectiveness of preventing electric shock to
human, the installation of ELCB is recommended, even with
three wire system.
• But ELCB needs effective earth to trip the power else
require a secondary path for current to create unbalance in
ELCB to operate and protect. Generally, the secondary path
is human being or insects.
• ELCB (as per the manufacturer’s instruction) shall be tested
once in month for effective protection.
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4. PROTECTION BY USE OF HRC FUSE
• The function of HRC or any rewirable fuse is to protect the equipment
/ appliances from over load and not for protecting earth leakage
and shock.
• The house hold appliances like Water Heater, Washing Machine etc
can be provided with glass fuse instead of HRC with cost
effectiveness for overload problem.
• There is no comparison of functions between HRC fuse and ELCB /
ELVD.
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5. NEGATIVE POINTS OF ELCB
• The ELCB is installed for an installation.
• Trips power to the whole installation incase of a single defective
appliance.
• Nuisance tripping in rainy season due to wet walls and poor insulation
of wires.
• Needs periodical testing for full effectiveness of ELCB (as per
manufacturer of ELCB).
• RCD (ELCB) does not guarantee protection against electrocution
and electrical circuits protected by it should be treated with the same
respect as any other. But it does help greatly to ensure that an
electrical shock is an unpleasant rather than a fatal experience (By
Mathew Marks – www.inceie.org.UK – i.e. National Inspection Council
for electrical installation contracting – UK and Independent
Regulatory Body for Electrical Industry – UK).
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6. • Our ELVD (working on Earth Loop Voltage Detection principle - ELVD)
with Circuit Breaker senses and isolates the faulty device so fast that
you won‟t have to feel that JOLT.
• “ NO JOLT FROM VOLT”.
• ELVD is far better than the conventional circuit breaker which has
delayed reaction presenting hazard.
• The operating time of ELCB is < 40 milli seconds (Clause 8.7 of IS
12640-1988) where as our ELVD acts within < 10 milli seconds.
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7. HOW THE ELVD IS THE SAFEST WAY TO PROTECT YOUR LIFE.
• An electronic sensor in the ELVD senses and compares the voltage of the
neutral and the earth terminals (Body) of the appliance.
• If the voltage level or fault signal exceeds 70 V a signal is sent to the circuit
breaker to cut off power to the faulty device. All other lights and electrical
devices in the home continue to function normally
• All that needs to be done to restore power to the appliance is to switch „ON‟
the ELVD after rectifying the fault in the appliance.
Foolproof system: Until the fault in the appliances has been fixed,
the ELVD will not allow the device to be powered.
Note: The sensing voltage can be set from 20 V to 100 Volts. However
from our field experience, to avoid nuisance tripping and shock, we have
fixed the sensing voltage at 70 V.
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8. To prevent electric shock Indian Electricity Rule 1956
stipulate the following:
Rule 33:
Consumer shall in addition (i.e. other than suplier‟s earthing
arrangement at the consumer premises) to the earthing provided by
the supplier, provide his OWN EARTHING SYSTEM with an
independent electrode.
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9. RULE 61:
The earthing system shall have, two different earthing system
through two different and separate earth electrode prepared as
per the standards.
RULE 61 (5):
The earth resistance at the earth pit shall be tested once in two
year for M V installation for proper and adequate earth resistance
( the value shall be less than 5 ohms).
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10. In practice none of the above three are never followed in
domestic and L.T industrial areas. In HV industrial
establishment, the records are kept to satisfy the
statutory inspection.
Hence, to prevent electric shock, the ELVD,
which operates even for unearthed system is
Ideal for shock prevention.
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11. ELVD can effectively prevent electric
shock to the operator and possible to
avoid fire accidents caused due to electric
current leakage in equipments like Air
Conditioners, Motors used in a Buildings.
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16. If the ELVD is installed for each machine in
conjunction with the MCB/CB of the main
Building/Installation the maintenance of earth pit
can be dispensed with or this can be considered
as an added protection to human life in case of
failure of earth connection, to trip the MCB.
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17. SPECIAL FEATURES
• Even if ground neutral loop resistance is high or open and consequent
voltage rise exceeds the predetermined value between the neutral and body
of appliance, the ELVD disconnects the appliances from power supply.
• Instantaneous operation i.e. Disconnects power appliance in less than 10
milli seconds.
• Designed to operate in both earthed and unearthed electrical system.
• Designed to protect both single phase and three phase appliances /
machinery.
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18. Advantage over similar unit available in the market to prevent electric shock
Item Earth Loop Voltage Detector with ELCB
Breaker (OURS) (Earth Leakage Circuit Breaker)
No.
1. Disconnects the defective unit alone. Disconnects power for the whole
All other lights and power circuit will installation / houses as ELCB is
have power. installed for the house and not for the
appliance.
2. No such necessity as power to the During nights when any one appliance
house will not be disturbed. develops defect, the whole house will
be in dark. Sometimes the services of
qualified technician is required to
restore power.
3. Disconnects power to the defective Will not operate when earth circuit in
appliances when the appliance is the house has high impedance or
powered, irrespective of earth open. A secondary path with low
connection healthiness. resistance is required (usually human
being / insects) to operate the device.
4. No maintenance and no testing. Periodical testing is must for the ELCB
(ONCE IN 30 DAYS).
5. Operates without earth connection. Good earth connection is a must for
Good for even two wire distribution proper operation.
systems.
6. No nuisance tripping of ELVD Trips due to leakage current during
rainy season caused by weak 18
insulation of wiring.

19. Can be used along with ELCB and gives additional protection (as
ELVD is compatible with ELCB)
EXTRACT OF CLAUSE A.02 AND A.2.4 OF IS 12640-1988
“It is Emphasized that the use of RCCB (ie.ELCB) is not
considered as a sole means of Protection and it does not obviate
the need to apply other protective measures”
(Clause A-02).
“It is essential that an RCCB (i.e.ELCB) is not used as a sole
means for protection against Direct contact” (Clause A.2.4).
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20. The following tests have been conducted in our factory as per
IS 302-1979.
a) Protection against electric shock (clause 8.0).
b) Temperature rise test as per clause 11 of IS 302.
c) Dry heat test as per IS 302.
d) Operating test as per product specification was conducted as
below:
• Sensing Voltage
• Tripping Time
• Maximum current breaking capacity.
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21. SPECIFICATIONS
• Voltage : a) 170-250 Volts 50 Hz
: b) 400-440 3 phase 50Hz
• Maximum Current breaking capacity : 20 Amps
• Rating : Continuous
• Power consumption : Negligible
• Operating Time : <10 ms
• Tripping voltage : >70 V
• Type : Self Resetting
(i.e. once the fault
in the load side is
cleared, the unit will allow
power to the load).
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22. TO SAVE LIFE USE ELVD
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27. Electrical Accidents-Statistics
•India
•
•Almost 12 people die due to electrocution every
day (Source -NCRB)
• 42 % of total fires occur due to electrical
sources (Source -OISD)
• 8% deaths that occur in factories are due to
electricity
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28. This product ELVD with Circuit Breaker is the patented product of
DOLPHIN SAFETY DEVICE. The patent Application
No.3690/CHE/2010 has been filed (under Patents Act 1970). The
product was developed by the inhouse Research and Development and
field tested for the last 6 years with M/s.Venus Home Appliances in their
product.
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29. THANKING YOU
DOLPHIN SAFETY DEVICES
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