Competence in Electrical Safety for Electrical Safety Officers

COMPETENCE IN
ELECTRICAL SAFETY
FOR ELECTRICAL
SAFETY OFFICERS
Ready Guide to some
Frequently Asked
Questions

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CONTENTS
Arc Flash
Batteries
Breakers
Cables
CEA MSES Requirements
Earthing & Flame Proof Equipments
General Questions
Lightning
LOTO
Measuring Instruments
Portable Equipments
PPE
Static Electricity
Transformers
4
12
14
15
17
24
26
30
30
30
31
31
33
33

ARC
FLASH

ARC FLASH
1
In what condition does an Arc flash happen? What are the precautionary measures to be taken
in order to avoid an arc flash?
Arc flash can happen when doing Energized Electrical works or when working around exposed
Energized conductor / circuit part.
Mitigation of Arc Flash hazards can be achieved through hierarchy of risk control methods such as
Elimination (avoiding live work), Substitution (operating from remote), Engineering control
methodologies (quick action devices), Administrative control & PPEs.
2
What are the Engineering controls for Arc flash hazards?
Engineering Controls include, but not limited to
Conducting Arc flash risk assessment, quantifying the incident energy levels and reducing it
using protection mechanism supporting with active arc detection devices
Guarding of Energized conductors to prevent Arc flash hazards.
Installing Infrared inspection ports to do Thermography
Remote racking of circuit breakers
The way to protect us from Arc flash hazards is either wearing of PPE or implementing Engineering
controls.
Both methods are practiced to reduce risk from Arc flash hazards.
Wearing of Suitable arc rated PPE is the least line of defense.
Engineering control is considered as effective method to reduce risk as it is applied to the source of
possible injury and they are less likely to be affected by human error.
3
How to calculate Incident Energy level for 33kV volt level & SC amps of 50kA?
Presently, As per IEEE standard 1584 – 2018 for Arc flash calculation available up to 15kV only.
Ralph Lee's theoretical calculation method can be used in this scenario.
Ralph Lee's method is more conservative than the practical estimation.

4
Is there any instrument to detect an arc flash?
Yes. Arc flash sensors are available.
Arc flash light sensor in combination with fast over current protection for feeder Arc flash
protection.
Arc Fault Detection Device (AFDD) are available for circuit protection"
5
6
7
Is an Arc flash required for 415V Panels?
Yes. It is required for 415V MV Panels.
Is Arc flash applicable for MCC and DBS?
Yes. Generally It is applicable for both MCC and 3 Phase Dbs.
What should be the frequency of the arc flash analysis? As per standard it should be 5 years,
however the physical property of the electrical panels never change which is measured during
the analysis. Also in NFPA 70E, there is no explanation as to why an Incident Energy analysis
needs to be done once in 5 years. Can you elaborate?
It is understood that due to any of the below reasons there may be a need to do the analysis.
There may be certain changes in a distribution system due to expansions / modifications (or)
There may be changes in the grid fault level due to increasing power demand (or)
There may be changes in the standards governing calculation of incident energy levels.
8
How to calculate Incident energy?
It needs to be calculated based on IEEE 1584 - 2018 standard.
Incident energy depends on factors such as short circuit level, time taken to isolate the circuit in
faulty conditions and working distance etc
ARC FLASH

ARC FLASH
9
Is Arc flash PPE required when panel doors are closed and restricted boundary is crossed?
Example: During meter reading from outside the panel.
For taking meter reading outside the panel, Arc flash PPE is not required as per NFPA 70 E table
130.5 ©.
Arc flash PPE is required only when live work activities like changing the components, trouble
shooting, altering the conditions or working around Exposed Energized conductor is performed
with doors and covers in open condition
10
11
Is Arc flash required for all live work and working near energized conductor?
Yes. Arc flash risk assessment & PPE is required for all live work activities and working around an
Energized conductor
Is working on test bench to test control and power circuits come under live work? Also, is Arc
flash assessment required for test bench work?
If there are no exposed energized conductors, it is not required to have Arc flash assessment.
If exposed energized conductors are present, Arc flash assessment is required.
12
Is Bus bar temperature monitoring of opening cable alleys with IR gun from a distance of 1M
considered as energized work or not?
For PCC & MCC panels (415VAC), Thermal imaging study done at a distance of 1mtr is NOT
considered as Energized work.
It can be noted that opening & closing of the door has a likelihood of Arc flash. Hence Arc flash PPE
needs to be worn during such activity.
13
Do we need to wear Arc flash rated clothes over our normal working clothes?
Yes. Arc rated PPE based on the incident energy level of the panel needs to be worn over the daily
wear while doing live work activity.

14
“Current measurement in cable alley using tong tester”. In this case, we are putting our hand
inside the cable alley. Will that be considered as “energized work”?
Yes. Work within Restricted approach boundary is considered as Energized work.
The work is considered as an activity having likelihood of Arc flash occurrence & hence Arc flash
PPE is to be worn.
15
Can we call “Energized work Permit” or “Energized work approval form”, as we have only three
types of permit (cold/ Hot and Spark Potential).
As per NFPA 70E, Energized Electrical Work Permit needs to be taken for live work activities.
16
Is troubleshooting in live 415V feeder considered as "Energized work"?
Yes. Work within Restricted approach boundary is considered as Energized work.
The work is considered as an activity having likelihood of Arc flash occurrence & hence Arc flash
PPE is to be worn.
17
Does Lockout Tag out activity come under live work?
Yes. It is considered as live work activity.
In MV panels, voltage testing will be a part of LOTO & in HV panel, removal & insertion of circuit
breaker needs to be done.
18
What is the condition to use Arc flash PPE? For example Breaker Panel ON / OFF Operation, live
line troubleshooting?
Operation of a circuit breaker (ON/OFF) does not require Arc flash PPE as long as you are confident
about the good healthiness/condition of the panel. If any maintenance has been done on the
breakers/panels then wearing of PPE is recommended for even switching of CB is recommended as
per NFPA 70E – 2021.
Live line troubleshooting requires Arc flash PPE to be worn based on the Incident energy level
ARC FLASH

ARC FLASH
19
During troubleshooting of control circuit (230V AC or 110V DC) in 11KV SWGR panel, in
isolation condition, Which kind of Cat class PPE needs to be used?
Condition 1 - If the control supply is isolated, LOTO done and if there are NO exposed energized
conductor present within the work area, Arc flash PPE is not required
Condition 2 - If the control supply is isolated, LOTO done and if there are other exposed energized
conductors present within the work area, suitable Arc flash PPE is to be worn
Condition 3 - If the control supply is Energized and if it is >120V, suitable Arc flash PPE is to be
worn
20
Is Arc flash suit required during power change over from DG to Board power or Board power to
DG?
It is not required if the power changeover arrangement system is having
Suitable interlock between both the breakers to prevent paralleling
Does not require racking in of circuit breaker
Does not require getting exposed to Energized conductors
21
Is there any minimum energy level above which Arc flash boundary is required to be
mentioned?
Arc flash boundary to be mentioned for all panels & DBs irrespective of the Energy level. However,
body protection is required where incident energy level is >1.2 cal/cm2.
22
Safe working Distance is as per which standard?
NFPA 70 & 70E
23
Is permanent boundary marking on floor required?
Generally it is recommended. Floor boundary marking is required for cautioning the operating
personnel and it is not a mandatory requirement.

24
25
In a PCC, Arc flash boundary marking needs to be done according to main EB breaker or
according to maximum Arc flash boundary of any feeder in that PCC?
Generally Arc flash boundary marking needs to be done based on the maximum arc flash boundary
distance for better safety
ARC flash sticker is required to paste at one location of main feeder or at each feeder?
Sticker not required for each feeder. It is meant for the panel. Max incident energy and PPE
requirement to be mentioned.
26
What is the distance required for red boundary and yellow boundary?
Red boundary - Restricted Approach boundary
Yellow boundary - Limited Approach boundary
(Colors of the boundaries are not defined in Standard). Both are known as shock protection
Boundaries.
Both are distance from the Exposed Energized conductor and are independent of each other.
These boundary distances for panels with different voltage level are given in NFPA 70E standards.
For example, a 415VAC MV panel will have
Restricted Approach Boundary - 300mm from Exposed Energized conductor
Limited Approach Boundary - 1000mm from Exposed Energized conductor
27
What is horizontal distance? (Working distance)
It is the distance between a person's chest area and a prospective Arc source.
28
Does Arc flash boundary need to be mentioned on small lighting panels / distribution boards?
Yes. If it is a 3-phase panel / DB, Arc flash boundary is to be mentioned.
29
Define qualified person?
One who has demonstrated skills and knowledge related to the construction and operation of
Electrical equipment and installations and has received safety training to identify the hazards and
reduce the associated risk
ARC FLASH

ARC FLASH
30
What is the panel thickness and material for minimizing Arc flash effects?
Panels are called arc rated switch gear (passive protection). Its thickness depends on voltage and
short circuit capacity. Types 1, TYPE 2, sub form A, B, C are available
31
What is the standard for panel thickness for various voltage levels?
IEC 62271-200
32
Is there any format to identify and include human error to find risk assessment?
Yes. It is available in NFPA 70E.
33
What is safety measure to be taken for a Thermography study to be carried out?
If the thermography is done outside of restricted approach boundary, Arc flash precautions are not
required.
If it needs access inside the restricted approach boundary, then shock protection and Arc flash
protection PPEs are required to be worn.
34
Is there any regulation or standard reference for people that should not sit in HT panel room?
Office facilities for functions not directly related to substation control should be housed in buildings
separate from the substation control building or in areas separated by fire-rated construction
provided in accordance with the separation provisions as per IEEE 979.
There is no explicit reference to restrict people sitting for related work activities.
35
Can we also use SMC sheets for insulation?
Yes. SMC sheet can be used as barrier to prevent direct contact with the Energized conductors.

BATTERIES

BATTERIES
1
What is the standard that should be followed for battery room with lead acid SMF battery
banks?
IEEE 1187 – IEEE Recommended Practice for Installation Design and Installation of Valve-
Regulated Lead-Acid Batteries for Stationary Applications
IEEE 1188 – IEEE Recommended Practice for Maintenance, Testing, and Replacement of Valve-
Regulated Lead-Acid (VRLA) Batteries for Stationary Applications
IEEE 1189 – IEEE Guide for Selection of Valve-Regulated Lead-Acid (VRLA) Batteries for Stationary
Applications
2
3
Please mention standards for PPE to be maintained in Battery room.
NFPA 70E & respective IEEE standards for each type of batteries.
Does VRLA batteries require ventilation arrangement?
Yes. VRLA battery room requires ventilation.
4
Should Battery Banks rack having Ni-Cd cells be earthed or not?
The metallic rack of the Ni-Cd battery bank needs to be earthed.
5
Is Hydrogen generated in Ni-Cd Battery? If so, rate of generation will be very less. So, is a H2
detector required or not?
Hydrogen will be generated in Ni-Cd batteries.
If the room & ventilation system are designed to limit Hydrogen accumulation to less than 2% of
total volume of the battery area and it is sufficient to prevent the formation of local pockets of
Hydrogen external to the battery, H2 detector is not required.

6
Should the Exhaust fan installed in Battery banks room be of a flameproof type or a safe area
type?
Generally If the battery room is meeting the natural and forced ventilation requirements of IEEE
standards, the room need not be considered as Hazardous location and it does not require
flameproof equipment.
7
We have 2000kVA UPS room with 120 dry batteries, is it sufficient to maintain the room by only
cooling or Can we do some extra activities by separating the batteries. Need your suggestions
Ventilation design & arrangement needs to be designed based on IEEE standards & manufacturer
recommendations.
BREAKERS
1
What should be the acceptable range for Dynamic contact resistance for CB?
It shall be as per Manufacturer specifications
BATTERIES

CABLES

CABLES
1
Cable laying depth is as per which standard?
As per IS 1255 - Code of Practice for Installation and Maintenance of Power Cables up to and
including 33kV Rating
2
3
What should be the distance between two cable markers for LT/HT Cables?
Cable route marker should be installed once in every 200mtr and at every turning.
Is it ok if I close cable entry to the plant with some kind of civil work?
Yes. Cable entry can be closed by civil work to the full thickness of the wall using material same as
the construction of the wall.
4
Is FR coating required on FRLS cable?
No. It is not required for FRLS cables as they have inherent properties of FR.
5
What should be the Insulation value of 11KV XLPE Cable?
Minimum 5 M is required for 11kV HT cable as per CEA MSES 2010 Regulation 33

CEA MSES
REQUIREMENTS
(Measures relating to Safety
and Electric Supply)

CEA MSES REQUIREMENTS
1
2
Do we consider the connected load to designate Electrical Safety Officer, irrespective of the
sector i.e. manufacturing or research?
Yes. For Every “Electrical Installation” having more than 250kW connected load, Electrical Safety
officer needs to be designated.
Is it only applicable for construction and commissioning time or applicable for running
operation?
It is applicable for running operation to designate Electrical Safety officer in Electrical Installations
having more than 250kW connected load.
3
I have a B.Tech and industrial safety certification and have 8 years experience in HSE field. Can
I become an Electrical safety officer?
No. Electrical Safety Officer shall possess a Degree / Diploma in Electrical Engineering with five and
ten years of experience in Operation & Maintenance of Electrical Installations respectively.
4
Who does a Electrical Safety Officer report to in a factory?
Electrical Safety Officer is not a separate position in a factory. They shall continue to do their
regular O&M activities. The Electrical Safety Officer is a responsibility to ensure the compliance of
CEA Regulatory requirements within the factory.
5
Can a C license holder become a chartered Electrical Safety Officer?
Yes. But the person shall possess B.E Electrical with 5 years of O&M experience or Diploma in
Electrical Engineering with 10 years of O&M Experience. The Chartered Electrical Safety Engineer
has to be Authorized by appropriate State Government through the selection procedure.
6
Can an Electrical Safety Officer himself do the self-certification without the help of Chartered
Electrical Safety Officer & submit the form to the Electrical Inspector?
Yes. Electrical Safety Officer can do Self Certification.
For regulation 43 requirements, recommended to take the support of Chartered Electrical Safety
Engineers to assist for Self-Certification of Electrical Installations.

7
Is it compulsory for an Electrical Safety Officer to take competency certificate? As in the plant
Operation and maintenance done by electrical supervisors? Please clarify.
Electrical Safety Officers are involved in testing and inspection of Electrical Installations which
requires competency certificate.
8
I'm have done B.Tech in Electronics and I have 10 years of experience. Can I become an
Electrical Safety Officer?
No. The person should possess Degree / Diploma in Electrical Engineering as per CEA 2010
regulation 5.
9
Test certification signing should be done by C-certificate holder or by Electrical Safety Officer?
Who can be SPOC for CEIG site visit - C-certificate Holder or Electrical Safety Officer?
Generally Electrical Safety Officer is the person responsible for getting the test certification & SPOC
for CEIG site visit.
10
If there is already a C license holder in a factory. Is an Electrical Safety Officer necessary in
addition?
The same C license holder if possess relevant experience can be designated as Electrical Safety
Officer. There is no requirement of additional person.
11
12
In Maharashtra, which is the appropriate department where we can apply for Electrical Safety
Officer certification?
Electrical Safety Officer is not a certification. It is a declaration to be given by the Organization to
the Electrical Inspectorate that a person is having required qualification and experience and hence
being designated as Electrical Safety officer for the Electrical Installations.
An Electrical Inspector inspects our premises every year. Do we have to submit the forms?
Yes. The Electrical Safety Officer has to inspect the installation and keep a record thereof in Form I,
II & III as the case may be. It can be submitted to the Inspector as and required by the electrical
inspector. He may visit irrespective of the forms submitted
CEA MSES

CEA MSES
13
What is the frequency for the self-certification? Form I, II and III.
Once in 5 years (or) as directed by the Electrical Inspector for self-certification. However, the
Electrical Safety Officer shall inspect the installation once in a year and keep a record thereof in
Form I, II & III as the case may be and submit records as and when required by the electrical safety
officer
14
Form I, II, III self-assessment copy needs to be kept with us or sent to the Electrical Inspector?
Form I, II, III shall be kept as a record and produced to Electrical Inspector when asked for. For
self-certification against CEA regulation 30 and 43, it has to be submitted to the electrical inspector
15
Is competency certificate a statutory requirement?
It is a statutory requirement as per Central Electricity Authority (CEA), Measures Relating to Safety
& Electric Supply Regulations 2010 to possess competency certificate for personnel involved in
O&M of Electrical Installations.
16
Is it mandatory to have Electrical supervisor license for all Electrical engineers working in an
Organization?
Any personnel designated to operate and carry out work on Electrical Lines & apparatus shall
possess Electrical License / certificate of competency / work permit as issued by the appropriate
State Government
17
If Engineers in an organization needs a License from statutory body, Can the organization itself
authorize them? Since all the contract employees should have Licenses.
Engineers shall obtain license from Appropriate State Government only which is termed as an
Authorization in regulatory context.
18
Is Electrical wireman / supervisory license required for every one like, Engineers, Electricians,
Contract workmen in an electrical maintenance team?
Yes. Persons designated for Operation and Maintenance of Electrical Installation require Electrical
license as provided by the State Government

19
If a person has good knowledge of Electrical system & has more than 10 years of experience but
does not have ITI certificate. Can he authorize an Electrical qualified person?
No. As per CEA MSES 2010, persons with required qualification and Experience are to be
designated for operation and maintenance of Electrical Installations.
20
If a person has Mechanical Qualification and has experience in Electrical Installation, is he
eligible for C Certificate?
No. Person should be qualified in Electrical domain for obtaining Electrical License
21
Is Interlock of Isolator with circuit breaker required for LV installation (415V)?
As per CEA MSES 2010, Interlock of Isolator with circuit breaker is required for 650V and above.
However it is a good practice to have interlocking for LV also
22
Does Rajasthan Governtment accept supervisory certificate from other states to work?
Rajasthan government recognizes supervisory certificate issued by other states to get exempted
from Examination. One has to apply for obtaining Supervisor competency certificate & Permit to
work as Supervisor to the State Government of Rajasthan.
23
We are not a Power generating company. Do we have to inform Electrical Inspector when the
Transformer fails?
Yes. Suppliers as well as consumers of Electricity have to report the failure of Transformers as
below.
Failures of Transformers and Reactors of 20MVA & 20MVAR and higher capacity shall be
reported to Central Electricity Authority (CEA) within 48 hours of occurrence.
The reasons for failure, measures taken to avoid recurrence of failure shall be sent to CEA within
one month of the occurrence.
CEA MSES

CEA MSES
24
Does CPP operator for plant operation require Power plant operator certificates?
Yes. Engineers, Supervisors & Technicians of Thermal Power plant (coal based, diesel engine based
& gas turbine based) shall be provided with trainings as prescribed in Schedule I of CEA MSES
2010 Regulation
25
What is Class A supervisor license in New Delhi?
It is Class I Certificate of Competency, issued for Electrical Engineers / Diploma holders with
relevant qualification & experience. They are entitled to works as Electrical Supervisors in New
Delhi.
26
Do Engineers and Electricians from Industries need to take training from external institutes
approved by CEA for compliance with Regulation?
Engineers & Electricians working in Industries are not required to take training from External
institutes.
Engineers, Supervisors & Technicians working in Thermal power plant, Hydro power plant,
Transmission & Distribution systems are required to undergo training as specified in CEA MSES
2010 Regulations.
27
28
What is the minimum number of wiremen & how many competency certificate holders are
required in a company?
The minimum manpower required in a company is not defined in any of the standards. However it
is recommended to ensure that all the O&M electrical persons are having valid license.
As per Regulation, is single electrician on site authorized to perform job (<=LV) (except height
work)? Or does he require another license holder to accompany him?
Regulation and standards did not address on lone worker hazards and requirements
29
Fire bucket is mandatory as per which Regulation?
Providing fire bucket is mandatory as per CEA MSES 2010 Regulation 27.

30
Which code speaks about 30, 300 milli amps RCCB?
RCCB of 30mA & 100mA is required as per CEA MSES 2010 Regulation 42 & IS 732 standards.
31
Why is the standard fence height 1.8m? Is there any code for that?
Fencing of 1.8mtr height is required as per CEA MSES 2010 Regulation 49.
The reason for 1.8mtr is not given explicitly. It is understood that the average height of Indian is
1.75mtr. Hence 1.8mtr is recommended to prevent intrusion & restrict accessibility.
32
What is the depth required for the stones in the switchyard?
Gravel depth in switchyard is 150mm.
Bottom 75mm layer shall be of 20mm dia gravels
Top 75mm layer shall be of 38mm dia gravels.
33
What is the significance of putting black stones in the switchyard instead of Cement Flooring?
The use of gravels in switchyard is to increase the foot resistance to the ground.
34
Is AED required in Electrical panel room? Which standard mentions this?
CEA MSES 2010 Regulation 28 requires Artificial Respirator to be placed in generating station /
substation / switching station. It does not mandate AED. However it is a good practice to keep AED
in plant premises.
35
For new installation of factory, Is Electrical safety audit needed?
Electrical Safety Audit can be done for the new installations to ensure design safety compliance &
whether Installation works are done as per Statutory & Standard Requirements.
CEA MSES

EARTHING &
FLAME PROOF
EQUIPMENTS

EARTHING
1
If power cable is Aluminum and earth conductor is copper, is there a thumb rule of keeping
same phase wire size?
No. If both the conductors are different, the conductor size needs to be calculated based on k1/k2
ratio factor.
k1 - k factor of power conductor
k2 - k factor of protective conductor
2
If motor casing is grounded is there any chance of getting indirect electric shock?
It depends on the grounding resistance of the motor and the person making indirect contact. That
is if the grounding resistance is too low (<1ohm) and if the person making indirect contact is
properly insulated (higher ground resistance) the possibility of Electric shock is low.
3
From which standard can Earthing cable size be selected?
IS 3043
FLAME PROOF EQUIPMENTS
1
What is the standard for FLP equipment maintenance?
IS/IEC 60079-17 - Explosive atmospheres, Part 17: Electrical installations inspection and
maintenance [ETD 22: Electrical Apparatus for Explosive Atmosphere]

GENERAL
QUESTIONS

GENERAL
1
2
What is the testing frequency of RCCB?
Good Practice is
Monthly - Functional Test by pressing the Test trip button
Yearly - Performance test using an RCD tester.
What is the method & testing frequency for RCBO?
Same as that of RCCB for testing Earth leakage protection
3
If ELCB is connected, should the Earthing conductor size be same as phase wire size? RCD will
disconnect within few millisecond, then why is the thick earth wire required?
As per IS 732 standards, RCCB is considered as Additional protection. The overcurrent protective
devices are the basic protection. For the basic protective device to operate, the earth conductor
shall be of adequate size.
4
What is the main difference between ELCB AND RCCB?
ELCB are voltage sensing and operating devices which measures the voltage of the protected
equipment and ground. If it exceeds 50V, it will disconnect the circuit.
RCCBs are current operated devices which measure the leakage current to ground and isolate
the circuit.
ELCBs are no longer available in the market /installed as it has certain disadvantages when
compared to RCCBs
5
Is it safe to use neutral as a control?
No. Only Phase should be used as control.
6
Is there any color code for names on feeders like yellow background and black letters?
There is no such color code standard for feeder identification. Only requirement is it has to be
painted.

7
Is MCB required to isolate Neutral also?
If the cross-sectional area of the neutral conductor is less than that of the line conductor, it is
necessary to provide overcurrent protection for the neutral conductor.
If the cross-sectional area of the neutral conductor is equal to the line conductor, and if the current
is not expected to exceed the line conductor current, overcurrent detection is NOT required for
Neutral.
8
Can you explain more on double insulation of portable tools?
Double insulation is achieved by 2 levels of insulation in the portable power tools.
First level is the basic insulation of the conductive parts
Second level is the plastic body construction
9
Do electrical rooms need to have fire rated doors? If yes, as per which standard?
Electrical Rooms shall be provided with fire rated door as per NBC 2016 standards.
It is understood that the doors shall be fire rated when the side it is communicating has the
potential of fire spread. If the outside of Electrical room is an open area, where fire spread cannot
happen, the door shall be of non-combustible material (metallic door) and need not be fire rated.
For MV panel room, NBC 2016 recommends to have fire rated doors.
10
If there is a building inside a Petrochemical complex, does it fall under NBC?
Yes. It is applicable for Petrochemical complex also.
11
Is the power quality test a mandatory under periodical inspection?
No. it is not mandatory under periodical inspection.
12
How to become NFPA authorized safety officer? Please give a few agencies name to attain
training and examination etc.
https://www.nfpa.org/Training-and-Events/Certification/Certification/Certified-Electrical-Safety-
Compliance-Professional
GENERAL

GENERAL
13
14
External painting of MCC panel should be done when panel is isolated or when it is in ON
condition
It is recommended to do painting when the panel is in isolated condition. The paint material being
flammable can result in fire / explosion.
What is the frequency for Thermography study?
Generally Once in a year. If more no. of failures/outages is noticed, the frequency can be increased.
15
What is the specification for dielectric floor?
As per manufacturer specifications and the voltage rating of the panel. Following parameters to be
considered based on voltage level
Weather resistance Dry coating film should pass 240hrs water immersion test.
Chemical resistance 5% H2SO4 - 48hrs Immersion 5% NaOH - 48hrs Immersion
Leakage current < 0.025mA (Third party test report required)
Insulation resistance at 500V >2.5x109 M Ohm (Third party test report required)
Break down Voltage in air >33KV For Class-A
System thickness 1.1-1.3mm for Class-A
Humidity resistance >5000 Hrs
Scratch Hardness >4.5Kg
16
What equipment should be used for working on live wires?
Meters with CAT III/IV rating as per the working panel (PCC, MCC, DB etc.)
Tools which are suitable for live working (generally indicated with double triangle symbol)
Shock protection PPEs

LIGHTNING
1
We are a car manufacturing plant, consuming power from grid at 132 KV line, is ESE Lightning
protection acceptable?
Early Emission type lightning protection is not accepted by NBC 2016 codes. Also, this type of
protection is not a part of IS/IEC standards. Hence, conventional lightning protection system needs
to be designed and installed as per IS/IEC 62305 standards.
LOTO
1
After LOTO is provided, do we need to earth the equipment? The person is working in pumps
alone and not in motor.
If the LOTO is made failsafe, i.e., there is no possibility of inadvertent energization, it is not required
to earth the motor when the work is done only on pump side and not on current carrying conductor
or near the current carrying conductor.
MEASURING INSTRUMENTS
1
What is minimum frequency for calibration of testing equipment like millimeters, insulation
tester?
Periodic calibration is required to be done once in a year for millimeters and Insulation testers.
2
What should be used for voltage measurement -single function meter? Is multi meter suitable?
Any hand held meter complying with CAT rating of IEC 61010 is suitable for voltage measurement.
3
Is FLP Multimeter available?
Yes. Intrinsically safe millimeters are available for use in Hazardous areas.
GENERAL

PORTABLE EQUIPMENTS
1
2
How to ensure the condition of double insulation is good in an old drilling machine
By doing visual Inspection to identify any physical damage
By measuring the insulation resistance between the phase lead & exposed conductive part of the
drilling machine
Can we use domestic sockets for power supply of two pin double insulated power tools?
Yes. Domestic sockets can be used in areas where dust and water ingress are not possible. Where
there is a possibility of dust / water ingress, weatherproof socket outlets can be used based on IP
rating.
3
is there any recommended maximum allowable length of cable from RCCB to tools, for
protection system effectiveness?
No. It shall be based on the leakage current of the cable network. Generally, for portable equipment,
cables up to 15mtr length are recommended
PPE
1
What is the lifespan of gloves or mat?
Gloves - if there is any physical damage noticed during field testing before / after use (or) if the
gloves fail the periodical testing (proof voltage testing)
Insulating mat - Life of mat is generally 10 to 15 years. It can be used as long as there are no
visual damages
2
How to test hand gloves yearly? Which type of test & Standard?
Air inflation test and dielectric test (proof voltage withstand test) are to be done annually.
Standards - IS 4770 & IEC 60903
3
Is third party testing of gloves mandatory?
Annual testing needs to be done. Air inflation test can be done internally using market available
inflators. Dielectric tests (for proof voltage / rated voltage) are done externally with vendors having
the measuring kit / setup.
GENERAL

4
Is there Class 0 category in hand gloves?
Yes. As per IEC 60903, Class 0 rating is available.
As per IS 4770, Type 1, 2, 3 & 4 gloves are available.
5
What is the rubber mat size above 66 KV?
Above 66kV, equipment will be in a switchyard (outdoor). Personnel safety is achieved, by earth
mesh / mat design, gravels, ensuring the Touch & Step potential within tolerable limit. Hence
Insulating mat is not required.
6
Is insulating paint advisable?
Yes. Insulating floors is acceptable by CEA MSES 2010 Regulation 19.
7
RCCB selection guideline is based on which standard?
IS 12640 / IEC 61008 standard.
8
Is it permitted to use a line tester in an industry?
Generally Line testers are permitted to be used in Industry. However usage of Line tester is not
safe. Hence it is recommended to use only non-contact voltage detectors/Portable millimeters to
prevent any direct contact.
10
What is the Rescue hook, discharge rod testing frequency and against which standard has it
been tested?
Specific to Earth discharge rod and shock rescue tool, there is no standard for defining
frequency of inspections.
If considering this equipment as live working tools, periodicity of inspection can be defined as
per manufacturer recommendations (IEC 61477).
Annual Inspection – Occasionally using tools & half yearly Inspection - for regular use tools is
preferred.
For live working tools used at <1kV, visual inspection is adequate. Regular Electrical testing is
not required
GENERAL

STATIC ELECTRICITY
1
How to measure static charge in a running line having pellets/powder? Also which instrument
should be used for static charge measurement?
It can be measured using Electrostatic Voltmeter
2
When was static electricity in Hydrocarbon industry adopted?
Static Electricity Indian Standard (IS 7689) was adopted in the year 1989.
3
What is the minimum size of equipment earth wire Cu / Al meant for static electricity
suppression
There is no minimum conductor size specified in standards. The conductor shall be mechanically
strong and the earthing resistance shall be <10 Ohm for metallic equipment.
TRANSFORMERS
1
Is Transformer oil drain pit compulsory for 1000 KVA?
Drain pit is required for Transformer having oil capacity >2000ltrs.
2
We have a 1000 KVA Transformer with 1350ltrs oil capacity. Do we require an Oil Pit?
No. Oil soak pit is required for Transformers having oil capacity >2000ltrs.
However, gravels shall be spread around the Transformer.
GENERAL

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