for Electric Power Distribution Board Safety Improvement

Dust Cleaning Equipment Operation Manual

NWK-99(OUTSIDE POWER POLE)

- Content -

1. Purpose and Features of Product

2. Summary of Work and Supplies
3. Equipment Operating Procedure
4. Equipment Operating Instruction
5. Preparation of Work and Checking of Environment
6. Cautions during work
7. Cleaning cycle by electric equipment
8. ESS dust cleaning cycle

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1. Purpose of Dust Cleaning & Features of Product features

A. Dust Cleaning Purpose

○ Electrical and Electronic Communication equipment is composed of a complex of
electronic devices such as precision circuits and highly integrated semiconductors.
When conductive or combustible dust or pollutant accumulates on the surface of
semiconductor and charging parts, Malfunctions and Short failures occur.
○ The purpose of Dust Cleaning is to effectively remove dust from the switchboard
to prevent electrical safety accidents, that is, corona, heat dissipation interference,
and lowering of insulation resistance. This Manual is composed of cleaning agents,
safety equipment and accessories.

B. Damage caused by Dust

1) Corona outbreak

○ What about corona discharge? It is an electrical phenomenon that occurs when

the fluid (air) around the conductor (electric wire) is ionized. If you hear a
crackling sound in a substation or under a high-voltage transmission line, you can
think of it as a precursor to a corona discharge. On a foggy or cloudy day, the
corona discharge becomes intense, and at night, the wires glow blue and white.
○ Damages include reduction in electrical efficiency, noise and disturbance in
nearby carrier communication facilities, and acceleration of corrosion in wires.
○ In particular, in the case of continuous corona discharge, deterioration due to
dust contamination of electrical insulators and connection parts may be the cause.
※ The photo below is a case where the root cause of the failure was resolved as a
result of dust cleaning for electric insulators in the INCOMING ASS (22.9kV)
where corona discharge continuously occurs.

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2) Interfere with heat dissipation

○ In general, if dust cleaning is performed in the case of electric switchboard, the

generated heat is lowered as shown in the picture below.
※ It can be seen that the temperature has decreased by -4.5℃ (↓13.3%).

○ However, there are cases where the temperature rises as shown in the picture
below after dust cleaning (before and after). This has a fundamental cause such as
aging of parts, and measures such as replacement of parts are necessary.
※ Even after dust cleaning, it can be seen that the generated heat increased by
+3.0℃ (↑12%).

3) Decreased insulation resistance

○ The following was carried out at the 1st water pumping station in the 00
Waterworks Business Headquarters.
-6.6kV panel 2 sides,
-6.6kV 400, 800, 1200, 1300HP, SC panel, motor operation panel, etc. 11 sides.
○ It was also conducted at the 2nd water pumping station, and the details are as
follows.
-6.6kV panel 1 side,
-6.6kV water supply main pump motor starter was carried out on 4 sides, and

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this is the data comparing the insulation resistance value before and after dust
cleaning.
※ The result shows that the insulation resistance (㏁) value is improved by ↑200%
from 2000㏁ to 4000㏁ after cleaning.

C. Cases of strengthening management standards for electrical and electronic

devices in preparation for dust damage

1) Inverter
○ Since inverters are electrical and electronic devices composed mainly of
semiconductor elements and are sensitive to environmental influences such as
temperature, humidity, dust, and vibration, daily inspection is essential to prevent
malfunctions in advance. In particular, when a lot of dust accumulates, insulation
resistance is reduced and equipment malfunctions due to interference with heat
dissipation, etc. Therefore, dust must be removed by setting a cleaning cycle.
※ The photo below is a case of solving the malfunction by removing the contaminated
dust of the elevator inverter using NWK-99 (Spray type).

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⚫ Manage the inverter temperature below 40℃
○ According to the inverter management regulations, the rated current of the
inverter decreases by 2.2% for every 1℃ rise above 40℃.

⚫Inverter usage environment and cleaning cycle

Division Item/cycle Details

ambient temperature -10℃~40℃ (without ice or frost)
storage temperature -20℃~65℃
environment Ambient Humidity Relative humidity 60% RH or less (no dew formation)
of use
Altitude and vibration 1,000m or less, 5.9m/sec (=0.6G) or less
surrounding
No corrosive gas, flammable gas, oil mist, dust, etc.
environment
cleaning
cycle 12 months Dust removal inside the inverter

D. Product features and specifications

1) Characteristics of detergent (NWK-99)

○ It is a non-conductive material with a breakdown voltage of 55,000V.

※ Dielectric breakdown voltage(KS C IEC 60156:2003) : 99,300V
○ Non-corrosive and does not damage the PCB and mounted components.
※ Corrosive (140℃ 19hr) (KS C 2101:2017): Non-corrosive
○ Flash point (ASTM D93-18) : 89℃
○ Easily removes dust between gaps in electronic parts with excellent penetrating
power.
○ After removal of pollutants such as dust, it evaporates without residue within 40
minutes.
○ It is a product with reduced harmful substances (low toxicity) and certified
eco-label (No. 4634).
※ Certification (January 1, 2006 ~ 11.5, 2020)

2) Product specification
Product Name Type Weight Remark
-Pressure: 5.2kg/㎠
NWK-99 Aerosol 539g -Absorbent cloth: 1000mm × 750mm
NWK-99(S) Pail 20ℓ
1) After cleaning, the residual cleaning solution evaporates in about 40 minutes in an environment of 20℃.
2) However, the cleaning solution that has penetrated between the gaps of electronic components (Magnet
S/W, Relay, etc.) that is difficult to contact with air may have a slow evaporation.
Recommendations 3) Therefore, the operator conducts air blowing immediately after cleaning to promote evaporation of the
cleaning solution that has penetrated between the gaps of electronic components such as magnet S/W and
relay.

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2. Summary of Works and Supplies
A. Summary of Works
○ The Operation Manual describing all the requirements in conducting works
cleaning dust which may cause the troubles in "Electric Distribution Board" must be
thoroughly digested prior to executing of works.
○ The equipment described in the Manual herein must be furnished in order to
assure the safety, and even in the event of using alternative equipments, the
equipment furnished shall comply with the functionality of equivalent level.
○ Electric switchboard cleaning should be performed by an electrician with more
than 10 years of experience in switchgear, capable of facility inspection and
emergency situations, to maintain and manage the highest quality.

B. Safety and Work Supplies

Manufactu
Item Equipment Name rer Specification Remark
Insulation Boots Over 26,500V
(Extra-high Voltage)
Insulation Glove Over 26,500V -Wear when power "ON" cleaning.
(Extra-high Voltage)
Insulation Glove Over 1,000V
(High Voltage)
Anti-static Cloth
Safety Safety Hat(Insulated) Over 7,000V ☞ Product provided live wire warning device.
Supplies -Mask : 6800
Mask -3M
-Filter : 6006 ☞ Full face covering type
Mask (Common) -3M ☞ Carbon Mask

Fire Extinguisher -Halon Fire ☞ To use the fore extinguisher suitable for
Extinguisher extinguishing electricity & oil related fires
-To classify
Compressor Ass`y -NWK
domestic/Inter-nat -Photo-1(No.4 equipment usage method)
3.5HP(220V/60Hz) ional ☞ Southeast Asia : 3.5HP(220V/50Hz)
Applications.
Spray Machine -NWK -L :Over 64㎝ -Photo-2
(L),(S) -NWK -S :Over 38㎝ ☞ Amount of spray : 490~550㎖/minute
Supplies Air Spray Machine -NWK -Length : 40㎝ -Photo-2
-A.D : 8mm -Work efficiency(detergent spraying & air
Coupring 2-prong Ass`y -NWK -Length:10m(2ea) hose)
-Coupring(1ea) -Photo-3
-A.D. : 10mm -Photo-4
Filter & Hose Ass'y -NWK -Length : 7~10m ☞ Check valve+Filter installed.
-I.D. : 8mm
Air Hose Ass`y -NWK
-Length : 10m -Photo-5
☞ To use as unbundled due to the
Reel Cable
generation of heat.
NWK-99 -NWK -Aerosol Type -539g
Cleaner
NWK-99(S) -NWK -Pail Type -20ℓ

Other ☞ Surface of cloth to have absorbing &

Adsorption Cloth -NWK Size : 1000×750mm
interrupting capability. (Sectionally coated.)

Paper Towel Industrial Type ☞ To have excellent absorption effect.

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C. Applies and Precautions

Division Target Equipment Remark(Photo)

Instrumentation control,
Hydro, Thermal, Nuclear, Electrical, Environmental
Cogeneration equipment Communication, Other
facility management
Power plant

Solar power generation Inverter

Elevator Instrumentation control, Inverter

Communicat Base transiver system,

PCB Card, Heat sink, Fan etc.
ion Communication relay,

Railway, Signal, PCB Card, Electrical

Electrical Switchboard
Subway Switchboard etc.

R o a d ,
Tollgate, Tunnel Detection Sensor, VMI, CCTV
Traffic

Cattle house Poultry, Swine, Hanwoo, etc. Electrical Switchboard etc.

Public institution facility

Electric room, Communication,
Others management, factories,
Signal, Control. etc
buildings, etc.
∙ Use the optical sensor parts after the cleaning solution is completely evaporated.
(Natural evaporation time : 40 minutes/20℃)
☞ Blow the compressed air immediately after cleaning to reduce evaporation time.
∙ Disassemble and clean the products or parts (PLC, Inverter, Magnet Switch, etc.) that
contaminants cannot escape.
Precautions ∙ Compressor may generate noise and cause malfunction of control circuit, so keep the
distance more than 2m and clean it.

∙ Restrictions on product use

☞ Do not use on computer keyboard, LCD, LED instrument panel.
☞ Be sure to perform reaction test on fine coated plastic and rubber products before use.

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3. Equipment Operating Procedure

A. Compressor and Moisture Eliminator (Photo-1)

○ The Moisture Eliminator provided is to automatically discharge water once fully

filled up thanks to its automated function. Yet, press the Discharge Button for 2~3
times at once by every hour prior to starting of works allowing vent of water in
advance.
☞ Even if the air hose length is 100m, the pressure is the same. So, do not move
the compressor by force, but connect the length of air hose.
○ Release the Discharge Button located at the bottom of Tank for 3 times (Prior
to work, lunch time & evening.) per day to remove water as well for the
Compressor.
☞ Water filled up is to be discharged. Lock the Discharge Button up with the wind
blowing sound indicating no presence of moisture.
(At this time, hold the handle and shake to allow water to escape toward the outlet.)
○ For Oil Type Compressor, routinely replace with the oil specified once by every
6 months for ideal life span management (8hr/day).

B. Connect Air hose and Cleaning solution supply hose to Spray gun. (Photo-2)

○ Use about 10meter length of Air Hose to connect with Spray Gun preventing
that the work piece object gets close to Compressor.
☞ Even though the length of the air hose is 100m, the pressure is similar.
Therefore, it is recommended not to move the compressor by force but to increase
the length of the air hose.
○ Routinely check the condition of Moisture Eliminator at about 12months cycle
based on 8 hours/day work, and replace as necessary.
☞ The Moisture Eliminator provided with equipment can be used semi- permanently
unless damage of component is incurred.
○ The Check Valve installed at the end of the hose for supplying detergent is
designed so that there is no problem in function even when spraying on an electric
panel with a height of 3m or more.

C. Raising Air Pressure by Engaging Power Supply on Compressor

○ Use the input power by connecting the 220V/60Hz (Chinese, Southeast Asian
220V/50Hz) direct power (switchboard)
☞ When using reel wire, unwind all reel wire to prevent load.
○ In case of compressor, the pressure when air pressure is completed is 0.7 ~
0.9MPa (kgf/㎠).

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☞ The Compressor described herein is default set up as 0.7MPa~0.9MPa
considering the efficiency of work.

D. Regulator

○ Regulate the pressure(0.7MPa~0.9MPa) and use fitting to the purpose of work.

E. Spray Gun

○ Check the pressure through the regulator before operation.

○ The spray gun is ① 65cm in length and ② 45cm in length. Keep at least 20 ~
30cm away from the electric panel to be cleaned.
○ The cleaning work is done horizontally and it is effective if it is done from top
to bottom.

F. Cleaning Agent

○ Make sure to only use the NWK-99(S) for Cleaning Agent.

○ Never invest any additives into NWK-99 product.
○ Firmly close the cover of container for raw material left over from work
preventing infiltration of external moisture, and then place it under storage.

G. Collection and Treatment of Adsorption Cloth

○ Cleanly wipe the surrounding of equipments such as floor and panel using the
adsorption cloth (Paper Towel), and collect the waste together with contaminated
cloth for disposal.
☞ It is effective to remove pollutants outside the switchboard using a dedicated
cleaning agent (HS-747).

H. Completion of work

○ After cleaning, check if there are any abnormalities in the electrical panel.
☞ Take measures to prevent theft of nearby facilities and materials.
○ After cleaning, follow the instructions of the site manager.

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4. Equipment Operating Instruction

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5. Preparation of Work and Checking of Environment

A. Preparation of Work

○ The Site Superintendent (Site Manager) shall visibly check the environment of
job site prior to starting of work, and be well aware of the location of emergency
exit and other safety related facilities.
○ The workers involved in site works shall put all the safety gears and apparatus,
and enter into the places where the cleaning work piece objects are located.
○ The equipments required in works shall be duly and appropriately arranged fitting
to each respective applications.

B. Installation of Job Site

○ When moving of work piece object is required, install the separate job site and
ventilation/exhaustion devices at the site as necessary.

C. Attaching Identification Number

○ Provide and attach labels in order on the work piece objects requiring detaching
(separation) during work process for safety in assembling.

D. Installation of Adsorption Cloth

○ To facilitate the collection of waste generated during work, an adsorbent cloth is

installed at the bottom (floor) of the object to prevent contamination.

E. Generator installation and operation

○ Safety management of fuels (diesel, gasoline, etc.) used for power generation is
important.
☞ Maintain and store at least a safe distance of 10M between generators and fuel,
and during breaks, stop starting and check for safety, such as overheating.
☞ Do not overheat the generator by exposing it to sunlight.
○ Be sure to check the capacity of the generator and compressor in advance so
that there is no overload.
☞ This compressor uses 3.5HP and the generator uses 5.5HP.

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6. Caution on Works

○ Before cleaning, the manager must check the electric switchboard and the discharge of
residual voltage in the condenser, etc.
○ Workers should be organized into a group of 4 people, but they should be a supervisor
(1 person), special high-pressure washing worker (1 person), and auxiliary worker (2
people), and the following safety rules must be followed.
○ Supervisors must keep a close eye on the site and respond to the situation in real time.
☞ For safety, the supervisor must open and close the cubicle 30 minutes before work,
check the safety violation factors, and immediately notify the safety manager and take
action when any dangerous factors are discovered.
(Safety violation factors: faulty lines, equipment, and all possible defects that may cause
danger)
○ For safety management, there shall be one cleaning worker in one work area.
○ The entry of outsiders into the workplace is prohibited. (Installation of control signs at
the entrance)
○ If the work object is in an enclosed place, work with adequate ventilation.
○ Do not possess or attach conductive materials (including metallic accessories) in the
workplace, and do not put items other than tools necessary for work.
(※ Cell phone not allowed)
○ Workers must follow the safety rules and must learn safety-related education and various
measures related to safety accidents and operating equipment before work.
○ Workers must wear standard safety equipment.
○ If an abnormality occurs during work, stop the work immediately, report it to the safety
manager, and restart it after the cause is found.
○ In particular, in the case of a compressor, it should be placed at a distance of at least
2m from the work object.
○ Work must be done in accordance with the instructions of the supervisor (site manager),
but do not arbitrarily perform work other than the permitted work.
○ When a unit (PCB card, other parts, etc.) is disassembled during work, an identifiable
mark or number tag should be attached to the unit to prevent the unit position from being
changed during installation.
○ Activities unrelated to cleaning work (eg smoking, eating, etc.) are prohibited in the
workplace.
○ Auxiliary workers safely wipe off contaminants inside and outside the work equipment,
tidy up the work area, and deal with the generated contaminants.
○ Fire-fighting facilities such as fire extinguishers should be placed in a location that can
be used immediately.
○ Do not use metal ladders, and make sure that the fall protection device is safe.

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7. Cleaning cycle by electric equipment

☞ Korea Occupational Safety and Health Agency: General technical guidelines for
the maintenance of electric facilities (cited by KOSHA GUIDE O-3–2011 /
December 29, 2011)

Maintenance cycle for each electric facility

Equipment / Equipment Name Task / function Cycle
Current and voltage measurement Weekly~monthly unit
Temperature measurement Weekly~monthly unit
Oil level measurement Weekly~monthly unit
Power / Power Pressure and vacuum gauge Weekly~monthly unit
Transformer Transformer oil analysis 1 time / year
Distribution
Insulation test 3-5 years
Transformers Winding test 3-5 years
Combustible Gas Analysis 1 time / year
Oil Dissolved Gas Analysis 1 time / year
Dry Transformer Clean, check and test 2 Year
Check 1 time / year
Electronic equipment Clean(Dust Clean) 3 Year
Adjustment, calibration 3-5 years
Check, Clean 3 Year
Circuit breaker Mechanical testing 2 Year
Electrical test 3-5 years
Visual check 3 Year
Clip Contact Pressure 3 Year
Fuse Terminals and
Fuse
Clips Contact surface Cleaning 3 Year
Discoloration, damage 3 Year
Vibration analysis 6 months
Stator and rotor Visual and mechanical check 1Cycle/Year
Clean
Rotary machine magnetwire Electrical test 1 time / year
Brush, current
collector ring, Visual and mechanical check 1 time / year
commutator
Plug, shielded wire
connector Check Monthly, when using
Wiring equipment Check Monthly, when using
Concent
Operation test Monthly, when using
Check, Clean Monthly, when using
Mobile power tools
Electrical test Quarter
UPS(Uninterruptible Visual inspection Quarter
Power Supply
System) Daily maintenance 6Monthly

☞ The maintenance intervals of the substation facilities vary depending on the installation
environment, but should be checked at least once every 6 to 8 weeks in industrial areas or
in coastal areas with high salt levels.

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8. ESS Dust Cleaning cycle

A) ESS(Enhancement of Energy Storage System) Operational Management Standards

○ On June 12, 2019, the Ministry of Commerce, Industry and Energy announced
that ESS fire accidents and industrial competitiveness support measures were to
strengthen management of overvoltage, over current, leakage, and temperature rise of
battery storage devices for solar cells.
○ The regular inspection interval will be shortened from the current four years to
one to two years, and ESS is designated as a specific fire fighting target and
mandatory installation of fire fighting facilities.
○ In particular, each business site decided to strictly manage the operating
environment such as the prohibition of additional charging after charging the battery
and the temperature, humidity and dust.

☞ In addition, the facilities installed indoors among the suspended business sites can be
restarted only after additional measures such as installing a firewall and securing the
separation distance.

(Operation and Management Standards Details)

Details
Division Item / Cycle
Before After
No additional charge after full
Filling rate Charge
charge
If dust accumulates in the
Temperature
battery module and condensation Temperature, humidity and dust
is generated and dried management of the battery
Operating Humidity repeatedly, fire may occur due compartment will be performed
environment
to insulation breakdown at the within the manufacturer's
Dust ground between the cell and the recommended range.
module enclosure.
Management Legal inspection
4 Year 1~2 Year
system cycle

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