TABLE OF CONTENTS
SCOPE
This Method
Statement identifies the work general steps, and the installation requirement
of grounding works including ground rod installation, exothermic welding,
grounding connection, ground resistance test and inspection to be done at -------project according to approved
construction drawings and specifications.
REFERENCES
1)
SAES-P-111 GROUNDING
2)
SAES-P-104 WIRING METHOD AND MATERIALS
3)
IEEE – 142 GROUNDING OF INDUSTRIAL AND COMMERCIAL
POWER SYSTEM
4)
ANSI/IEEE - 142 GROUNDING OF INDUSTRIAL AND COMMERCIAL
POWER SYSTEM
5)
NFPA - 70
NATIONAL ELECTRICAL CODE
6)
SAES-A-114 Excavation and Backfill
GENERAL
Personnel, Duties and Responsibilities
a)
Electrical
Manager / Electrical Engineer
i.
Delivering
the relevant documentation and the required materials to the Construction
Personnel.
ii.
Implementation
and supervision of the work activities.
iii.
Notification
after the work completed to Quality Group (Aramco and Contractor). QC
Contractor personnel should be informed and verify the work before Saudi Aramco
inspector as required.
iv.
Taking
part in the definition of any corrective actions required ensuring the correct
Resolution of the non conformity.
v.
Checking
the adequacy of subcontractor’s personnel, equipment and promoting any required
actions necessary to achieve the construction targets.
b)
Electrical
Supervisor
i.
Lead
and plan the work according to the contract drawings and Company standards
c)
Quality
Control Inspector
i.
Inspect
the work to comply according to contract drawings and Company standards.
d)
Safety
Supervisor
i.
Make
sure that all safety measures are complied before starting the work.
ii.
Provide
safety instructions to the workers
iii.
Hand
in hand with the site electrical Supervisor that the work is carried out
according to safety controls and procedure.
Qualifications and Trainings
a)
Supervisors
and inspector must be eligible and competent for the job.
b)
Laborers
must able to understand his work and require trade certificates if necessary.
c)
Conduct
trainings regularly to maintained safety and good workmanship.
Equipment and tools
a)
Cable
cutter
b)
Set
of spanner
c)
Metal
knockout punch
d)
Electric
grinder
e)
Core
drilling machine
f)
Welding machine
g)
Grounding
kits
h)
Cad
welding kits
i)
Cable pulling tools (jacks, winch, cable
baskets…)
j)
Ground resistance tester
k)
Insulation
resistance tester
l)
Boom truck/crane (when needed)
m) Forklift
SAFETY
1)
Safety induction shall be done before starting at work
site.
2)
Tool box talk shall be conducted daily prior to work
start.
3)
Obtained required work permit before initiate the
activities.
4)
Proper personnel protective requirement (PPE)
including flame resistant clothing (FRC), hard hat, safety shoes, shall be worn
when working on or near electrical equipment.
5)
SECL safety supervisor shall carry out the safety site
inspection to ensure that safety requirement laid in the safe working plan is
allowed during and after the work start.
6)
Barricading and warning sign must be posted around the
working area.
7)
Precision tools, hand tools, and special equipment
must be calibrated, inspected, periodically and bearing the latest color code
before use.
8)
Should be provided proper earthing and appropriate
rated ELCB for welding machine, generator, compressor etc.
9)
All electrical extension cables shall have a proper
6FCi outlet
10)
During lifting operation safety pre-caution should be observed.
11)
All lifting activity shall have a third party certificate
or inspection and color coded, area shall be barricaded during lifting and
rigging work.
12)
Required wind velocity, as per Luberef standard. If
the wind velocity is 32km/h lifting operation must stopped.
13)
Construction area fire point wall be established where
fire extinguisher, fire blanket stored and keep ready for use, additional fire
extinguisher will be provided for immediate work areas during certain phase or
work that is particularly susceptible to fire.
14)
Emergency procedure shall be communicated to all
workmen, availability of first aider / nurse, fire fighter with equipment.
15)
Housekeeping shall be conducted on a regular basis to
maintained orderly, clean, healthy and safe work place.
Working inside the trench
/ tank, vessel
a)
Tool
box talk shall be carried out.
b)
If
the trench excavation is more than 1.2 meters deep, Confined space entry permit
shall be ensured and all confined space entry procedures shall be complied.
c)
Ensure all worker assigned are confined
space entry trained. Log sheet of personnel entering and exiting the excavation
shall be maintained.
d)
Ensure
the both the edges of trench excavation are properly sloped to allowed entry
personnel inside.
e)
Ensure
sufficient safe access and egress ladder shall be provided and maintained
properly.
f)
Daily excavation checklist, tanks, and
vessels shall be ensured and maintained at all times.
g)
Supervisor
must be there.
Working at heights ( if neccessary )
a)
Full
body harness with two lanyards must be issued for all workers working on 1.8
meters and above and 100% tied off shall be strictly implemented.
b)
Samsung
work at height training must be completed by the involve workers prior to
mobilization to the site.
c)
Tools and materials must be secured and tied
properly when using and lifting on height respectively
d)
Working
area should be barricaded.
e)
Scaffolding
material shall be free of defects, inspected and approved by Samsung.
f)
Mobile elevated working platform must be of
good running condition, free of defect and with valid third party inspection
certificate.
g)
Barricading and warning signs must be posted
around the working area.
h)
All working platform should be inspected and
tagged.
SUBMITTALS
1)
Grounding cable
2)
Cable lug
3)
Cable clamp
4)
Cable connector
5)
Bolts and nuts
6)
Unistrut
7)
Ground bar
8)
Anchor bolts
9)
Grounding rod
10)
Shrinkable tube
11)
Contact grease
12)
Exothermic materials
13)
Copper tape
14)
Ground cable
METHODS
AND GUIDLINE FOR GROUNDING INSTALLATION
Installation of underground grounding
conductor
a)
General
requirements: ensure that installation will be carried out in accordance to
approved project drawing and specification; the following shall be verified and
studied upon execution of grounding.
i.
Released
and approval of construction drawing will be verified
ii.
Verify
location of area where grounding works will be executed
iii.
Conduit
size and lay-out verification (as per drawing schedule)
iv.
Grounding
cable size, route and length
v.
Types
of connection which will be made
vi.
Stop-up
locations
vii.
Grounding
rod location
b)
Survey
route and location of installation in reference to construction drawing prior
to installation, any obstruction/variations found during survey shall be
reported and an alternate route shall be sought from contractor through
technical query, items written in the above paragraph (par. A) will be considering
during survey.
c)
Grounding
cable installation and cable pulling
i.
Prepare
materials and tools for grounding cable pulling; ground cable may be pulled
along with any other cable, grouped in accordance to cable schedule.
ii.
Verify
the location of cable pulling activity
where to place the cable drum
iii.
Preparation
of cable reel for pulling
a. Carefully place the cable in spool
stand , ensure that cable drum will not dropped
b. When cable reel needs to be rolled,
roll drum in accordance to manufacturers’ roll direction, reel shall be not be
rolled in sharp edges, should be rolled on hard surface and avoid sinking to
soil when handling.
c. Lifting equipment, tools, rope,
slings, men, and soil must not contact the cable or cable protective covering
during shipping and handling, and DO NOT apply mechanical force or pressure to
the cable surface during handling.
d. Cable will be pulled manually; an
adequate number of manpower will be used when pulling longer cable.
e. Check interconnection drawing subject
for termite welding.
Exothermic welding procedure
a)
Verify
number of grounds for exothermic weld connection.
b)
Ensure
that mould to be used is correct for the conductor size and application, do not
modify mould.
c)
Mould
to be used may absorb moisture, propane torch may be used to dry out the mould
on both side thoroughly.
d)
Dry
up the conductors for connections, use wire brush to prepare the conductors
surface. Scrape the outer surface to remove dirt and oxidation.
e)
Insert
the conductors and position them for the connection. Close the clamp tightly
after connections
f)
Insert the steel disk on the mould and
ensure that it is properly seated.
g)
Take
a tube of properly sized welding material and quickly pour into the mould.
h)
The
bottom of the tube contains compressed material. Tap the bottom of the tube to
loosen this material.
i)
Pour of this compressed material over the
welding material in the mould crucible.
j)
Close the lid and pour the remaining 75% of
the compressed material into the slot of the mould cover.
k)
Aim
the flint igniter from the side. Ignite the material on the mould cover and
quickly withdraw the igniter to prevent fouling.
l)
Allow approximately 30 seconds for
completion of the reaction and solidification of the molten material.
m) After removing mould, joints shall be
cooled down. Clean joint with soft bristle then apply corrosion inhibitors or
protective epoxy compound suitable for grounding joints corrosion protection.
Application of compound may be done after completion of cad welding in each
area and as joints cooled down.
n)
Check
that the number of usage for mould does not exceed the required usage stated by
manufacturer. Thermo weld mould can be reused as per manufacturer instructions
thus need to recheck for any damage upon using.
Installation and Connection of Rod
a)
Check
that the rod is free from non-conductive coatings such as paint or enamel prior
to being driven to the ground.
b)
Length
of the rod shall have a minimum length of 2.4 meters. Jointed rods are
permitted but each joint must be at least 2.4 meters long.
c)
The
ground rods shall then be brought to their marked location. Clear the area from
debris and perform excavation and drilling of earth for rod installation.
d)
Set
up the drilling machine (core drill will be used as applicable) in place
carefully and drill thru the marked location to the maximum depth of the drill
bits prepared. then position the ground rod in the drilled hole
e)
Insert
the fabricated pipe driver from the top of the ground rod and pile drive the
rod into the drilled hole. When ample length of the rod has been driven into
the earth, manual hammering of the rod can be done.
f)
Inspection has to be raised to verify and
confirm that the installation of the first rod is acceptable.
g)
After
that, connect the second rod with the coupling and pile drive the second rod in
the same manner as the first till the whole length of the rods are into the
earth with the required clearances within the ground rod pit.
h)
Permanently
concealed ground connections are required; make the connections by the
exothermic process to form solid metal joints. Make accessible ground
connections with listed grounding connectors.
i)
The resistance value of each earth rod shall
be noted and the total earth rods to be installed until the prescribed
resistance value are acceptable.
Installation of Grounding Bar and Plates
a)
Check
mounting details of ground bar (welding or bolting). Ensure that ground bar
will be completely installed.
b)
Plate
will be welded to equipment or structural column as shown on project drawings.
c)
Seal
stub-ups of cables to be connected to the ground bar or plate.
Grounding Connection and Bonding
a)
Equipment
Grounding :
i.
Check
that grounding cable pulled for equipment grounding complies with project
drawing, cable specification, schedule and lay-out.
ii.
Prepare
grounding cable for termination crimping cable ends with proper connector or
lugs.
iii.
Apply
insulation tape (green or yellow/green tape) to cable lugs.
iv.
Fix
ground cable for equipment's provided termination point with screw or bolt as
specified.
v.
Tighten
bolts in accordance with the appropriate torque value as applicable.
b)
Cable
Tray Bonding :
i.
Drill
hole at side rail of cable tray from each end of the splice plate
ii.
Check
bonding jumper to be used for cable tray as per requirement. Properly crimp
connectors for bonding jumper or as specified if braided jumper will be used.
iii.
Place
screw head on inside of cable tray, put jumper on outside the cable tray add
flat washer, locknut and tighten.
iv.
Bond
cable tray to the local ground grid or ground electrode at both end points
ensuring that bonding continuity is met throughout all the racks in the system.
c)
Conduit
Bonding :
i.
Prepare
cable for bonding by crimping with correct lugs or connectors.
ii.
Connect
grounding jumper at both end points by bonding to a grounding conductor, a
grounded metal enclosure, or to a grounded metal cable tray with approved
grounding clamps and conductors connected externally to the conduit.
NON-SUBSTATION FENCES SHALL BE GROUNDED :
a)
Fences
which are within 10 m of an enclosed ground grid or ground loop that is
connected to equipment operated at 1000v or greater shall not be PVC coated and
shall be grounded at intervals not exceeding 15 m to the ground grid or loop.
b)
All
fences within 3 meters of a ground grid or ground electrode shall be bonded at
the nearest fence posts to the ground grid or ground electrode.
c)
Fences
that pass under transmission line operating at 69 kV and above shall not be PVC
coated and be grounded at intervals not exceeding 15 m.
d)
Fences
that cross over a ground grid or conductors that connect two ground grids shall
not be PVC coated and shall have a bond between the grids or conductors and the
nearest post. If the crossing area is extensive, the bond is required every 50
m.
INSPECTION
& QUALITY RECORDS
a)
All
stages of work shall be inspected in accordance with the approved project
quality control inspection plan.
b)
Inspection
/ Quality activities shall be as per the corresponding SATIP and SAIC.
c)
Fall-Of-Potential
Test I Ground Resistivity Test will be done in compliance with IEEE Standard 81
on the main grounding electrode or system.
d)
For
large ground works, it may be necessary to locate the current and potential
electrodes a considerable distance from the connection to the network. In this
instance, the current and potential electrodes can be placed at a minimum angle
of 90 degrees.
e) In all cases step and touch potentials
during ground faults shall not exceed the safe values defined in IEEE 80
(SAES-P-111 Sec. 8.2).
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