1) Does a totally enclosed air-over machine has a fan (No fan)

2) In High pot tests, A voltage higher than the rated voltage is applied for a given time to
determine the adequacy against the breakdown of insulating material and spacing under normal
condition

3) Insulation system can be classified into

Class A: Having thermal endurance upto class A temperature Rise decided by

experience or accepted test

Class B: Having thermal endurance upto class B temperature Rise decided by

experience or accepted test

Class F: Having thermal endurance upto class F temperature Rise decided by

experience or accepted test

Class H: Having thermal endurance upto class H temperature Rise decided by

experience or accepted test

Type of Motors w.r. to Temperature

Class Y - 90 Deg C

Class A - 105 Deg C

Class E - 120 Deg C

Class B - 130 Deg C

Class F - 155 Deg C

Class H - 180 Deg C

The motor shall have a non hygroscopic, chemical and humidity resistant insulation system.
The thermal rating of the insulation system shall be minimum of class F.

4) In the name plate A letter CODE On alternating Motor shows it’s Locked Rotor KVA Per
Horse Power : ref 10.37.1 in NEMA-MG- 2009

5) Clearance Distance: The clearance is defined as shortest distance through the air between
two conductive elements.

Creepage Distance – Shortest distance on the surface of an insulating material between two
conductive elements

For The given voltage, creepage distance is more than the clearance distance; It depends on
the installation Category and degree of pollution

6) Use Frequency – 60 Hz in States and 50 Hz in India

7) 4.4 Operating overload-ICS1

For the purpose of this standard, the maximum operating overload of industrial motors and their
control apparatus shall be considered to be:
(a) For AC apparatus — 6 times normal full — load current;

(b) For DC apparatus for full-voltage starting — 10 times normal full-load current;

(c) For DC apparatus for reduced-voltage starting — 4 times normal full-load current;

(d) For apparatus where the operating overload is automatically limited—100 percent of the
limited value.

These overloads are currents that may persist for a very short time only, usually a matter of
seconds.

8) ICS-3 Class E1 Controllers

The test cycle of a Class E1 controller shall be three CO unit operations at intervals of 2
minutes.

8.1.5.2 Class E2 Controllers

The test cycle of a Class E2 controller shall be three CO unit operations separated by the
interval required to renew the fuses, to inspect and, if necessary, replace any renewable
contacts. Replacement of a vacuum, or any other sealed type interrupter is not permitted

9) ICS-3 Procedure
To determine compliance a contactor shall be subjected to ten make and break operations at
the crossover current or ten times the continuous current rating of the contactor whichever is
greater

10) Insulation deterioration during the service life of electrical apparatus results from various
combinations of such causes as progressive aging, moisture, mechanical damage, and
excessive voltage stress. In addition,

11) Condensation: ICS 3

If moisture condensation occurs inside an enclosure, corrective action, such as the
installation of a space heater, should be taken. Refer to the manufacturer for the recommended
heater size for the circuit

12) ICS 3: Interlocking

Interlocking shall be provided by mechanical means or by combination of mechanical and

electrical means and shall provide the following features:
(a) Prevent the isolating means from being opened or closed unless all contactors are open
 (b) Prevent the opening of a door to a medium-voltage compartment when the isolating
means is closed
(c) Prevent the isolating means from being closed when the door of any medium-voltage
compartment of the controller is open

13) DOE: Verification of De-energized Condition

2.50
Verification shall be made to ensure that all circuits, parts, and other sources of electrical
energy, including mechanical energy, have been disconnected, released, or restrained.

14) DOE: Tests and Visual Inspections

2.56
A qualified worker shall verify that all personnel are in the clear and that all tools, electrical
jumpers, shorts, grounds, and other such devices have been removed, so that the circuits and
equipment can be safely energized.

2.60
15) DOE: Qualified workers shall be knowledgeable of, and trained in, safety-
related work practices
16) 141: In specifying a transformer for a particular application, the following items
comprising the rating structure should be included:
a) Rating in kilovoltamperes or megavoltamperes
b) Single-phase or three-phase
c) Frequency
d) Voltage ratings
e) Winding connections, delta or wye
g) Impedance (base rating)
h) Basic impulse insulation level (BIL)
i) Temperature rise
j) Voltage taps

18) Factory tests on motors completely assembled in the factory

The following tests shall be performed on all motors prior to shipment from the factory.that are
completely assembled in the factory and furnished with a shaft and a complete set of bearings:
a) Measurement of winding resistance
b) No-load readings of current, power, and nominal speed at rated voltage and frequency
c) Mechanical vibration check in accordance with 6.9, using either elastic or rigid mount
d) High-potential test in accordance with Paragraph 12.3 of NEMA MG 1-2006, Part 12

19) 20.1 Rated short-time withstand current

The rated short-time withstand current of a LV ac switchgear assembly, or a LV dc switchgear
assembly rated 300V or 325V (dc), is the designated limit of available (prospective) current at
which it shall be required to withstand its short-time current duty cycle (two periods of 0.5 s
current flow, separated by a 15 s interval of zero current

The rated short-time withstand current of a LV dc switchgear assembly for use with
solid-state Rectifiers (regardless of rated voltage), or rated above 325V (dc), is the designated
limit of available (prospective) sustained rms current it shall be capable of carrying for not less
than 250 ms.

20) Rod entry test

6.2.9.1 Method for ventilated enclosures
This test shall prevent the insertion of be made to demonstrate that a straight rod having a
diameter of 13 mm cannot be inserted into the opening.

21) 37.20.1 The operation of auxiliary switches and contacts for circuit-interrupting and
switching devices shall be designated as follows:
a is open when the device is in the de-energized or non-operated position

7.1.3.4

a is open when the device is in the de-energized or non-operated position

b is closed when the device is in the de-energized or non-operated position

aa is open when the operating mechanism of the main device is in the de-energized or
non-operated position

bb is closed when the operating mechanism of the main device is in the de-energized or
non-operated position

e, f, h, k are special contacts and auxiliary switches other than a, b, aa, or b

52TOC / NO (a): open when the circuit breaker is not in the connected position

52TOC / NC (b): closed when the circuit breaker is not in the connected position

22) Closing and tripping

Mechanical means for closing and tripping manually operated breakers and for manually
tripping electrically operated breakers shall be provided and shall be accessible without
exposing the operator to live parts.
Manual closing is not required for electrically operated circuit breakers.

23) Outdoor LV switchgear

a) Shall require the use of a tool to gain access to the equipment cavity or have provision for
locking.
b) Shall have doors that are equipped with latches and stops to hold the doors in the open
position.

c) Shall prevent the insertion of the end portion of a straight rod of the specified diameter into
the equipment cavity of the enclosure.

24) Covers for switch gear

For ease in handling, cover plates that are intended to provide access for inspection and
maintenance shall not exceed 1.12 m2 (12 ft2) in area or 27 kg (60 lb) unless they are equipped
with lifting means or hinges

It is recommended that these covers be equipped with one or more alignment pins (on the
cover or the enclosure) to facilitate removal and installation.

25) Shutters

On MC switchgear, automatic shutters shall be provided to prevent incidental contact with the
live parts of the primary circuit when the removable element is in the test position, is in the
disconnected position, or has been removed.

26) 12.00 Angular displacement (nominal) between voltages of windings for three-phase
transformers

The angular displacement between high-voltage and low-voltage phase voltages of three-phase
transformers with ∆-∆ or Y-Y connections shall be zero degrees.

The angular displacement between high-voltage and low-voltage phase voltages of three-phase
transformers with Y∆ or ∆Y connections shall be 30º,???? CORRECT

27) NETA-5.3 Test Instrument Calibration

1. The testing organization shall have a calibration program which assures that all applicable
test instruments are maintained within rated accuracy for each test instrument calibrated.

33) NETA 7.12: Perform resistance measurements through bolted electrical connections with a
low-resistance ohmmeter,

28) NETA : Test Values

Inspect bolted electrical connections for high resistance using one or more of the
following methods:
1. Use of a low-resistance ohmmeter in accordance with Section
2. Verify tightness of accessible bolted electrical connections by calibrated torque-wrench
method in accordance with manufacturer’s published data
3. Perform thermographic survey in accordance with Section

29) Cl1, Cl2 – Division 2 – abnormal condition

30) The Purpose of conduit sealing: to contain the gas from going outside or explosive gas
seeping

31) API 541,841,540 Definition

32) API 541 definition

33) All enclosure parts shall have a minimum rigidity equivalent to that of sheet steel with a
nominal thickness of 3.0 mm (1/8 in.).

b) Air deflectors shall be made of corrosion-resistant material or shall have corrosion-resistant

plating or treatment.

c) All the enclosure’s bolts, studs, and other fastening devices up through M12 (1/2 in.) size
shall be ISO 3506 series or AISI 300 series stainless steel (SS 304) When the motor is
specified to be installed offshore on a production platform or similar marine installation,
AISI 316 material shall be supplied in lieu of the 300 series fasteners. Aluminum is not
used. There is no SS 300.

34) API 541

Totally enclosed machines (TEFC, TEPV, TEWAC, and TEAAC) shall meet the following
criteria.

a) Fan covers
b) The air intake opening shall be guarded by a grill or a metal screen fastened on the
outside of the fan cover.
.
c) Totally enclosed machines shall be equipped with a plugged, threaded drain connection
located at the lowest point of the frame. This connection shall be shown on the outline
drawing.

d) Requirements for heat exchanger tubes

35) REG WELD REPAIR: API 541: Weldable grades of steel castings may be repaired by
welding using a qualified welding procedure based on the requirements of Section IX
4.4.10.3.1 Structural welding including weld repairs shall be performed by operators and
procedures qualified in accordance with AWS D1.1 and ISO

The vendor shall be responsible for the review of all repairs and repair welds to ensure that they
are properly heat treated and non destructively examined for soundness and compliance with
applicable qualified procedures.

36) Soft Foot Check API 541

Prior to any mechanical running test, a check for “soft feet” shall be made

After the machine has been aligned, shimmed, and firmly secured to the test base,
a dial indicator micrometer oriented in the vertical direction shall be attached at the
mounting foot to be checked. The micrometer is then zeroed, the mounting bolt or bolts
loosened at the foot, and the change in micrometer reading noted
This soft foot check shall be performed at each mounting foot with the other feet
secured until all micrometer change readings are less than 0.025 mm (0.001 in.).
If there are intermediate bases, this check shall be performed at each interface between the
machine and the test floor.

37) API 541

The motor shall be operated at no load for at least one hour after the bearing
temperatures have stabilized. Stable temperature is defined as a change of not more than
1 Deg C in 30 minutes

38) API 541: Space heater leads shall be accessible without disturbing the shipping
package and shall be suitably tagged for easy identification.

39) A ``defeater`` mechanism allows the enclosure door to open with the operator in the
on position. It defeats the safety lockout mechanism. The defeat function allows qualified
personnel to by-pass the door interlock when the switch is in the ON position by means
of a tool.

40) Condensation occurs when the warm air at 20 Deg C or 30 Deg C Come into contact
with Cold body say 0 Deg C.

41) Back feed – DOE exists as a result of induced voltage or voltage back feed after specific
parts of the circuit have been de energized. If the circuit, when you have back feed A power
station will typically back feed (and thus consume power) when it is shut down, Generators back
feed easily. Power grid loads may backfeed if they also have distributed generation installed,
such as a grid-connected photovoltaic solar power system or a microturbine-based power
generator
It is also possible for an electric motor to temporarily back feed if it is mechanically driven

Hazrads of Backfeed: The real danger of the backfeed comes from the assumption that the
conductor or equipment is dead or de-energized when in fact, it is not.
How to deal with back feed:
a) Using transfer switches
b) By limiting distributed generation capacity to less than is locally consumed,
a) By installing a reverse-power cutoff relay that opens if back feeding occurs

Corrosion of SS, Aluminum, Copper

42) SS 304 is widely used for corrosion protection

SS 316 is used for corrosion protection in marine environments
Aluminum is not used for Corrosion protection because
a) it can suffer galvanic corrosion with more cathodic material.
b) It may become anodic and get corroded
c) Oxidizing layer can be formed. This should be removed when preparing the joints
because electrical conductivity of aluminum oxide is poor
d) It does not have the strength of SS

Corrosion: aluminium vs. copper

Copper can be used against corrosion, even in the offshore atmosphere except ammonia
atmosphere. But strength and cost is a consideration compared to SS

So Aluminum is not corrosion resistant. Aluminum strength is also poor

So Steel has more strength, corrosion resistant and economical So Used in is a construction
material, and mostly used for making steel structures, steel doors and handles, nails and bolts,
frames,

Note: Copper is resistant to corrosion in underground environments, and steel can rust. Copper
will corrode in moist air, slowly, and darkens forming a layer of copper oxide. Steel, with more
carbon and iron in it, will also rust in moist environment. Here note it is only steel and not
the SS, SS will not corrode.

43) TRUE POWER/ACTUAL POWER

 TRUEPOWER
POWER FACTOR= =cos ∅
APPARENTPOWER

POWER FACTOR FOR RESISTANCE = 1 and POWER FACTOR FOR INDUCTANCE = 0

44) Power Factor

Power Factor: True power or Actual power/Apparent power

True Power is the Power supplied to load, Apparent Power = RMS voltage x RMS current.
Power factor of 0.7, Means you need 1.4 times more voltage that is 2 times more loss

Power factor of an AC motor (or generator) is the ratio of the kilowatt input (or output) to the kVA
input (or output) and is usually expressed as a percentage.

P.F = Cos (Angle) If PF =1 Voltage is in phase with current, it is pure resistive load

If P.F = 0, the load is pure inductive.

If PF increases, Current decreases

The problems of LOW PF

1) Penalty from utility company if PF is lower than 0.95
2) Low efficiency
3) Large equipment size is needed
4) Greater conductor size and cost
5) High current

PF Improver: Static capacitor, Synchronous condenser, Phase advancer. To improve PF

power capacitor is added in parallel. Power capacitor shall not be connected to the load end of
electronic control.

30.2.2.9 Power Factor Correction

The use of power capacitors for power factor correction on the load side of an electronic
control connected to an induction motor is not recommended.
For such applications the electronic control manufacturer should be consulted.

POWER FACTOR CORRECTION

The maximum value of corrective kVAR should not exceed the value required to raise the no-
load power factor to unity. Corrective kVAR in excess of this value may cause over-excitation in
high transient voltages.

PF can never be more than 1.

45) For every increase of 10 Deg C, the motor winding expected life is reduced by one-
half.

What is Service Factor? What is its definition? Can it be greater than 1?

Service factor: Permissible Horse Power/Rated Horse Power

Service factor of an AC motor is a multiplier that when applied to the rated horsepower indicates
a permissible horsepower loading that may be carried under the conditions (IEC standards do
not recognize service factor).

Usually TEFC motor has S.F =1, If it has S.F 1.15, for ex 10 H.P motor can be over loaded
temporarily 11.5 HP.

4.2.1.4 Machines shall have a 1.0 service factor rating. In applications that require an overload
capacity, a higher base rating instead of a service factor rating shall be used to avoid exceeding
the temperature rise

NOTE Applying a motor such that it will operate at greater than its rated power (i.e. using a
service factor higher than 1.0), shortens the life of the machine.
This higher temperature operation negatively impacts the life of the insulation and other
components of the machine
Purpose:
• To accommodate the inaccuracy in prediction
• To accommodate the temporary overload
• To accommodate Unbalance supply voltage

46) Duty factor: Duration of on period/Total period. Duty factor 1.15 means 10 HP motor can
be used for 11.5 hp for short duration

Motor sound power level shall not exceed 90 dBA at no load (TEFC SQ cage Motor of 500
HP and Less)

47) Aluminium has more thermal expansion than copper. So its use is avoided.

48) Don’t use high current rating renewable element in the place of low current rating renewable
element (Device damage will occur).

49) Don’t use low short circuit current rating devices instead of high short circuit current rating
devices (Frequent interruptions will occur).

50) Interrupting rating of the protective devices should be greater than the short circuit rating of
the protective devices.
51) 7.5.6 Interrupting Ratings

Protective devices used in control circuits shall have interrupting ratings not less than the
available short-circuit current at the protective device location in the circuit.

ICS-3 The ultimate-trip current rating of over current (Overload) relays shall be less than
the service-limit current rating of the controller.

Inserting a circuit breaker of a higher rating does not necessarily increase the capabilities of the
switchgear assembly or imply that the assembly is capable of operation at the ratings of the
circuit break

3) NETA-7.15.3.2 Bearing insulation-resistance measurements shall be within

manufacturer’s published tolerances.

4) NETA Verify that the ground lead on each device is individually attached to a ground bus
or ground electrode.

52) API 541 Bearings shall be electrically insulated.

53) In power engineering, a one-line diagram or single-line diagram (SLD) is a simplified

notation for representing a three-phase power system. The one-line diagram has its largest
application in power flow studies. It is a form of block diagram graphically depicting the
paths for power. Elements on the diagram do not represent the physical size or location of the
electrical equipment, but it is a common convention to organize the diagram with the same left-
to-right, top-to-bottom sequence as the switchgear or other apparatus represented. A one-line
diagram can also be used to show a high level view of conduit runs for a PLC control system

A secondary advantage to using a one-line diagram is that the simpler diagram leaves more
space for non-electrical, such as economic, information to be included.

54) NFPA-Markings
(A) Cable Marking. Type FCC cable shall be clearly marked with
1) Identification of the manufacturer
2) Material of conductors
3) Maximum temperature rating
4) Ampacity – Means ampere capacity
5) Temp rating

55) NFPA: Table 430.7(B) Locked-Rotor Indicating Code Letters Code Letter
Kilovolt-Amperes per Horsepower with Locked Rotor
56) NFPA: Zone 20, 21, and 22 Locations for Combustible Dusts or Ignitible
Fibers/Flyings
NFPA-70: Foot Protection. Where insulated footwear is used as protection against step and
touch potential, dielectric footwear shall be required. Insulated soles shall not be used as
primary electrical protection

57) NFPA-70E: Beam Shutters or Caps. Beam shutters or caps shall be used, or the laser
switched off, when laser transmission is not required. The laser shall be switched off when
unattended for 30 minutes or more.

58) Why Teflon is used-high temp for electrical connection for water tightening in outer space
connection

59) 0.1 6.2.5.1.3 Test duration

For LV ac switchgear, the test current shall continue for two periods of 0.5 s separated by a 15 s
interval of zero current. At the option of the manufacturer, a single period of 1 s duration may be
used

60) Interlocks

Mechanical interlocks shall be provided in LV switchgear as follows:

a) To prevent moving the circuit breaker to or from the connected position when the circuit
breaker is in the closed position.

b) To prevent closing the circuit breaker unless the primary disconnecting devices are in full
contact or are separated by a safe distance.

c) Circuit breakers equipped with stored energy mechanisms shall be designed to prevent the
release of the stored energy unless the mechanism has been fully charged. Operators and
service personnel shall be protected from the effects of accidental discharge of the stored
energy by any of the following means:

61) Liquid Immersed Distribution Power Regulation Transformer

First letter: Internal cooling medium in contact with the windings:

O Mineral oil or synthetic insulating liquid with fire point _ _300 oC 12
K Insulating liquid with fire point > 300 oC
L Insulating liquid with no measurable fire point

Second letter: Circulation mechanism for internal cooling medium:

N Natural convection flow through cooling equipment and in windings
F Forced circulation through cooling equipment (i.e., coolant pumps), natural convection flow
in windings (also called non-directed flow)
D Forced circulation through cooling equipment, directed from the cooling equipment into at
least the main windings

Third letter: External cooling medium:

A Air
W Water
Fourth letter: Circulation mechanism for external cooling medium:
N Natural convection
1
F Forced circulation [fans (air cooling), pumps (water cooling)]

ONAN/ONAF. The transformer has a set of fans that may be put in service as desired at high
loading. The coolant circulation is by natural convection only.

ONAN/OFAF. The coolant circulation is by natural convection only at base loading. However,
the transformer has cooling equipment with pumps and fans to increase the power-carrying
capacity at high loading.

62) 12.00 6.5 Tank pressure requirements

6.5.1 Maximum under rated conditions
Tank pressure under rated conditions for sealed transformers shall not exceed two
atmospheres (203 kPa)

What is 7 psi without distortion and 14 psi without rupture

63) Supervisor should take all corrective actions necessary to address an employee's concerns.

64) Weld shall be post relieved

65) NETA 5.3: Calibrating standard shall be of better accuracy than that of the instrument
tested. Calibration is done to check the accuracy of the Product

66) DOE – 2.13.1.6: Lockout procedure: De-energized condition shall be checked by voltage
verification test. If the voltage is > 600 V. The equipment shall be checked for proper operation
immediately before and immediately after the test. Hazard may exist due to back feed after the
device has De-energized.

Here whether LO is lone is ok or Both LOTO is a must. Whether LOTO include voltage
verification test ? or is Voltage verification test needed after LOTO also ? .

67) Nameplate marking

The following minimum information shall be given on switchgear assembly nameplates:
a) Manufacturer’s name and address
b) Manufacturer’s type designation
c) Manufacturer’s identification reference
 d) Rated maximum voltage
e) Rated power frequency
f) Rated continuous current (main bus)
g) Rated short-circuit withstand current (where applicable)
h) Date of manufacture
i) Instruction manual number

68) Is SS 300 can be corrosive? 316 belong to 300 series only

. Although Aluminum oxide gives corrosion protection It will have pores through which corrosion
may occur. So Again Oxide formation will interfere with Welding

Only Copper free aluminum gives corrosion protection Because Copper and Aluminum will
produce bimetallic corrosion of more anodic material aluminum.

Again Aluminum wire when they are connected to copper connecters Aluminum will have more
thermal expansion. So periodically connections have to be checked and tightened

Again Aluminum should not come into contact with Magnesium Oxy chloride in fire proofing
material which may corrode Aluminum

Use SS 304 or 300 Series for Corrosion protection and 316 for corrosion protection in
the Marine environments.
PLEASE NOTE Normal steel will corrode. Only SS will not corrode.
Copper can be used even in marine environments. But Copper shall not be used in
Ammonia environments
Copper will carry more Current than Aluminum for the Given Size. To carry a given
current Aluminum will have 1.67 times the area of copper conductor but the weight of aluminum
is half that of copper conductor. In general copper is more costly than aluminum

69) Shipment: What should be accessible without opening the enclosure?

Leads for space heater

70) ATPV: Arc thermal performance value

Arc Thermal Protection Value (ATPV) is “the incident energy on a fabric or material that results
in sufficient heat transfer through the fabric or material to cause the onset of a second degree
burn based on the Stoll Curve

National trend is single layer HRC 2 daily wear , and HRC 4 flash gear

First Degree Burns

The least severe burns are those that affect only the outermost layers of the skin (epidermis).
After the initial shock, a first degree burn is the equivalent of a minor sunburn. Signs of a first-
degree burn include:
• Red skin that is painful to the touch
• Dry in appearance

ATPV category; Category 1 ‐ 4 cal/cm2 Category 2 ‐ 8 cal/cm2 Category 3 ‐ 25 cal/cm2

Category 4 ‐ 40 cal/cm2

Working on levels above 40 cal/cm2 should be avoided because of the blast hazards caused by
arc flash.

The onset of second degree burn can occur at 1.2 Cal/cm². Many people use the analogy of
1.2 Cal/cm² being equal to holding a finger over a flame for one second. So it is considered as
the ARC acceptable limit Boundary
Industry standards and government agencies agree that 1.2 to 2.0 cal/cm2 is an
acceptable worker incident energy level. This exposure to arc radiant heat energy may cause a
curable 2nd degree burn of the epidermis indicated by painful red skin and blisters. The
damaged epidermis will regenerate without scare tissue.

So Cat 4 s required in more serious situation than cat 1

Remember: If using face shield for arc flash protection be sure to check the Minimum ATPV
rating (in cal/cm²)

71) Safety Shoe: Test clearance after impact test shall be for men 0.5 inch and woman 0.468
inch
Test clearance after Metatarsal impact test: men =1 inch, woman = 0.937 Inch

 Shoe Height 6 inch

 Height of sole spike shall be minimum 4 mm
 Heel height: 34mm
 Toe height: 24 mm

72) .Insulation Shoe Size.

73) PPE

Personal Protective Equipment: Remember – PPE is a last line of defense!

The needed PPE are

• Flame resistant clothing will self-extinguish, thus limiting the injury

• Body area under non-FR clothing is often burned more severely than exposed skin

• Energy goes up dramatically as distance from arc drops as per inverse squire Law
It ( means what ) must be capable of withstanding the application of 14,000 volts at 60 hertz
for one minute with no current flow or leakage current in excess of 3.0 milliamperes, under dry
conditions
If an employee provides their own protective equipment, the employer shall be responsible
to assure its adequacy, including proper maintenance, and sanitation of such equipment.

74) a portion of the answer (API 541)

75) Sin Cos angle of voltage and current related to power factor or apparent power.
76) 6, 3, 2, 1 h for bearing temperature stabilizing temperature (API 541)
79) If θ is the phase angle between the current and voltage, then the power factor is equal to the
cosine of the angle. Since the units are consistent, the power factor is by definition a
dimensionless number between -1 and +1
80)Insulation shoe thk up to 33kV 2-3 mm rubber.
82) Enclosed electrical equipment: marking, should have current, voltage, wattage and
frequency (DOE 9.8.1)
83) Notes taken during the site inspection is called
a) Reference drawing
b) Field draingone Line dia
c) Dimensional drawing
d) Illustrative dia
e) One line dia
f) Wiring dia-Connection
g) Wireless connection dia
h) Check answer in ICS 1, SIEE guide or check all places
Actual dimension shall be recorded in inspection reference drawing (SIEE
9.2) and dimensions which exceed the tolerance are treated as
nonconformity or deviation

84) Similarly check for PD3 in all places

85) As per NFPA 70 E
a) Safety Refresher training shall occur Annually. But Retraining shall be performed
at an interval not exceeding 3 years
b) Training verification : Employer shall verify at least annually that employs training
required by this section is current
86) But HDBK says safety refresher training is recommended at intervals not to exceed 3
years
87) Electrical conductors that have been disconnected but Not under LOTO is not considered as
electrically safe condition. LOTO shall always include voltage testing requirement where
there is direct exposure to electrical hazard
88) Arc flash risk assessment shall be reviewed periodically at interval not exceeding five years
89) Arc flash boundary is the distance at which incident energy level is 1.2 cals/Cm 2. It is also
the energy level at which 2nd degree burn start to occur
90) Only qualified persons can defeat or bypass an electrical safety interlock i.e.
temporarily .When the work is finished safety interlock should be returned to its operable
condition.
91) PPE requirements address only thermal effects and not any other physical trauma.
92) Arc flash PPE is decided either by incident energy analysis method or Arc Flash PPE
category method. But NOT BOTH.
93) ARC flash Hood or Balaclava Protection if the energy exposure exceeds 12 cals / cm2.
Heavy duty leather gloves should have ATPV values in excess of 10 Cals/cm2. Heavy duty
Leather foot wear shall be used when exposure is greater than 4 cals/cm2
94) Fire resistance alone is not OK. It shall be arc resistant
95) Laser: Any device that produce radiation in wave length range of 100 nm to 1 mm by
controlled stimulated emission
96) Condensation will occur when warm air come into contact with colder body. Colder body
need not be at 0 Deg C. At 0 Deg C , ice will be formed
Condensation will form when Air at 30 Deg C come Into Contact with
a) 30 Deg C
b) 20 Deg C
c) 0Deg C
d) Less than 0 Deg C
97) Condensation will form when R.H is 100%
98) R.H shall not be more Than 60 % , If it is more than 60 % it may form condensation and it
may create shock hazard Also some pyrophoric materials Like some metallic salts can Fire.
99) But in the case of the need for conductive floor in the case Electro static explosive device A ,
R.H of more than 60 % is needed to Discharge the accumulated charge
100) Aluminum will corrode heavily if it comes into contact with Magnesium oxy chloride if fire
proofing material