Saudi Aramco Pre-Commissioning Form, P-004, Low Voltage Cables
The Saudi Aramco Pre-Commissioning Form, P-004, Low Voltage Cables provides a field installation check list for low voltage cable installations. P-004 has a broad check list of visual and mechanical inspections, as well as the listed electrical tests that are required for low voltage cable installations. Space is also provided on the form for test data.
WORK AID 2 (Cont'd)
FORM # P-004 (7/94) SHT 1 of 2
Saudi Aramco Pre-Commissioning Form Low Voltage Cables
Equipment Type: User Reference:
Equipment No.: Description:
BI/JO NO.: Plant No./Location
Ref. Drawings & Documents Manufacturer:
Model No.: Serial:
Commissioning Date:
Field Installation Tests
Visual and Mechanical Inspection
YES NO
1. Inspect cables for physical damage and proper connection in accordance with single line diagram.
2. Cable connections shall be torque tested to manufacturer’s recommended values or values recommended in P-000.
3. Verify proper terminals and crimping die are used on cable and that crimping procedure is proper.
4. Verify cable color coding.
Electrical Tests
YES NO
1. Perform Megger Test on each cable with respect to ground and adjacent cables. For cables 250 volt and less use 250 volt megger, for cables 250 volt to 600 volt use 1000 volt megger, for cables above 600 volts and less than 1200 volts use 2500 volt megger.
2. Perform D.C. High Potential Test on cable with respect to ground and adjacent cables. High Potential test cables 250 volt to 1000 volt at 2000
3. Perform continuity test to insure proper cable connection.
NOTE: This non-mandatory form may be used as the starting point to assemble a pre-commissioning checklist. Entries should be revised, added and deleted and approval adjusted to reflect the needs of the Project Acceptance Committee.
SAPMT INSPECTION OTHER DEPT. OPERATIONS
APPROVALS Signature &
Date
Saudi Aramco Pre-Commissioning Form, P-004, Low Voltage Cables Figure 18
WORK AID 2 (Cont'd)
FORM # P-004 (7/94) SHT 2 of 2
Saudi Aramco Pre-Commissioning Form Low Voltage Cables
Equipment Type: User Reference:
Equipment No.: Description:
BI/JO NO.: Plant No./Location
Ref. Drawings & Documents Manufacturer:
NOTE: This non-mandatory form may be used as the starting point to assemble a pre-commissioning checklist. Entries should be revised, added and deleted and approval adjusted to reflect the needs of the Project Acceptance Committee.
SAPMT INSPECTION OTHER DEPT. OPERATIONS
APPROVALS Signature &
Date
WORK AID 2 (Cont'd)
Information, Formulas, and Tables for Use in Evaluating the Results of Insulation Resistance (Megger) Tests
Low voltage (600 V and below) cables, including splices to existing cables, must be 500 V dc megger tested after installation (but prior to backfill in the case of direct buried cables) and prior to placing in service.
The following are the types of megger tests that can be conducted:
• Short time or spot reading
• Time resistance
• Dielectric absorption ratio
When the dielectric absorption ratio megger test is performed, the polarization index can be determined through use of the following equation, in which the readings are of resistance:
Figure 19 provides insulation conditions for dielectric absorption (60/30) ratio results and polarization index (10/1) ratio results.
WORK AID 2 (Cont'd)
Insulation
Condition 60/30 - Second
Ratio 10/1 - Minute Ratio (Polarization Index) Dangerous
Questionable Good
Excellent
----1.0 to 1.25 1.4 to 1.6 Above 1.6
Less than 1 1.0 to 2 2 to 4 Above 4
Dielectric Absorption Ratio Chart Figure 19
Information, Formulas, and Tables for Use in Evaluating the Results of DC Hi-Pot Tests The dc hi-pot test should be secured if one of the following situation occurs:
• The duration of the test has expired
• A rapid rise in leakage current occurs
• The polarization index < 1
The following are the characteristics of a satisfactory dc hi-pot test:
• The leakage current gets smaller over time.
• The polarization index > 1.
• The leakage current increases on a straight line as voltage is increased. No "knee" is noticeable in the leakage current curve.
Figure 20 shows a failure forecast table that is used with dc hi-pot test results to predict when a cable failure could occur.
WORK AID 2 (Cont'd)
ELASTOMERIC (EPR) FAILURE FORECAST FROM DC HIGH POTENTIAL TESTING
DC Test Potential at Start of Current Runaway
(% of AC rms Voltage) Estimated Failure Time (Years)
200 0.0
300 0.5
500 2.0
800 Over 6
Table of Elastomeric (EPR) Cable Failure Forecast Figure 20
WORK AID 2 (Cont'd)
An example of dc hi-pot test data is shown in Figure 21. Figure 21 shows both good and bad insulation test data.
Use Word 6.0c or later to
view Macintosh picture.
Example of DC Hi-Pot Test (Good and Bad Cable Insulation) Figure 21
WORK AID 2 (Cont'd)
Evaluating the Cable Tensionometer (Strain Gage) and Pulling Devices
The following are the inspections and checks that should be performed during the evaluation of the cable tensionometer (strain gage) and pulling devices evaluation:
• Check that the proper cable pulling hardware is provided.
• Check the actual conduit or cable tray bend radii to ensure conformity to the original pulling tension calculations.
• Check the cable reel assignments and cutting schedules.
• Check the minimum and maximum pulling specifications (e.g., tensions).
• Check the arrows on the cable reels for the direction to pull the cable off of the reel.
• Inspect the cable for jacket damage.
• Ensure that all water and debris are removed from underground conduit prior to the cable pull.
Point-to-Point Verification of Cables
The following are the inspections and checks that should be performed during the point-to-point verification of a cable installation:
• Verify that circuit separation is maintained between the cable and any other cables in the run.
• Verify the clearance between the cable and process piping or other process facilities.
• If a raceway (e.g., cable tray and conduit) is used for the installation, verify that the cable is correctly installed in the raceway.
• Verify that the cable supports and fasteners are installed correctly and that there is no cable damage.
WORK AID 2 (Cont'd)
Figure 22 shows Saudi Aramco and industry splices and terminations installation requirements.
General
requirements Compression-type connectors are the preferred method for splicing or terminating cable conductor ends. Compression (crimped) type connectors must be used for terminating stranded conductors.
All compression connectors must be tinned copper, and they must have a manufacturer's reference compression die number and conductor size printed or stamped on the connector.
The metallic composition of the crimp connector and the metallic composition of the cable conductor should be similar.
The use of solder lugs is prohibited.
Cable terminators that rely on inwardly protruding flat springs (tines) for grounding the metallic sheath or armor are prohibited.
Armored cable (unless specifically designated as Type AC per NEC Article 333) must be manufactured to IEC 502 and must have galvanized steel wire armor or galvanized double steel tape armor. For installation and application purposes, the cable is considered to be equivalent to type MC (metal clad) cable, except suitable armored cable terminators (glands) must be used to terminate and ground the armor.
Type MC cable and armored cable must be permitted to be installed exposed where it is not subject to damage by vehicular traffic or similar hazards. Other types of cable must not be installed exposed above
ground, and must be installed in cable trays, conduit, or, where flexibility is required, in flexible conduit.
To prevent water from entering the end of the cable, heat shrinkable boots should be placed over the crotch of a three-phase cable and shrunk into place.
Lugs for bolting terminations to buswork or equipment should be ordered with NEMA standard spacing (15 mm holes on 45 mm centers).
Equipment and buswork termination pads also should be specified with NEMA standard spacing. Cable terminal lugs should be a one hole, two hole NEMA, four hole NEMA, or pin terminal design.
Saudi Aramco and Industry Splices and Terminations Installation Requirements Figure 22
WORK AID 2 (Cont'd) Outdoor
requirements Outdoor riser terminations of shielded, solid dielectric cables must have a creepage path to ground of 40 mm (1.5 in) per kV phase to phase and should use either heat-shrinkable termination kits, with skirts or porcelain dry type terminators (Joslyn PSC or equal).
If three-conductor cables are used, the cable crotch should be sealed.
PILC and VCLC high voltage cable terminations require the use of compound filled potheads or suitable heat-shrinkable terminations.
Indoor
requirements Indoor terminations of shielded, solid-dielectric cable should provide stress relief and should have a minimum creepage path to ground of 25 mm/kV (1 in/kV) phase to phase.
Stress relief for indoor shielded, solid-dielectric cables may be provided by stress relieving tape, premolded stress cones, heat shrink stress tubing, or taped cones. Normally all that is required for an enclosed termination is to strip the cable jacket and shield to the designated length, connect (e.g., crimp) a termination lug, and install a stress cone.
Saudi Aramco and Industry Splices and Terminations Installation Requirements Figure 22 (Cont'd)
The following is a general terminations and splices visual inspection/evaluation procedure for low voltage cable installations:
1. The inspection personnel should verify that none of the following are present:
• Wrap-around, rigid snap-on, or adhesive-type markers to identify wiring at terminal blocks.
• Solder lugs.
• Twist-on connectors (wirenuts).
• Cable terminators that rely on inwardly-protruding flat springs (tines) for grounding the metallic sheath or armor.
WORK AID 2 (Cont'd)
2. The inspection personnel should check that the terminations are one of the Saudi Aramco preferred methods.
3. The inspection personnel should check that the terminators that are used for the installation are one of the recommended types.
4. The inspection personnel should check the installation against the splices and terminations installation requirements that are shown in Figure 22.
The following is an excerpt from GI 2.710, New Construction Check List Example, that illustrates the overall check list and sign-off for major pieces of electrical equipment.
3. Electrical Equipment
All substations, power cable, electrical equipment, including lighting and wiring, to be checked for proper application, operation, and grounds.
Distribution panels, switches properly identified, and all energization certificate requests signed.
Construction Agency
Power Distribution Dept.
Project Inspection
Commissioning (Note 1)
WORK AID 2 (Cont'd)
Figure 23 shows an excerpt from GI 2.710, General Instruction Manual, that illustrates the inspections and tests that should be performed on major pieces of electrical equipment prior to the turnover of a facility.
DIVISION OF RESPONSIBILITIES FOR TURNOVER SUPPLEMENT NO. 2.710-6
MECHANICAL
Agency (Note 2) Proponent 1. General
2. Civil/Structural 3. Electrical 4. Piping
5. Mechanical Equipment 6. Fire & Safety Systems 7. Communications 8. Instrumentation 9. Catalyst, Chemical and
Dessicants - Review and Approve - Witness (Event) - Inspect (Work)
- Operate Process Equipment - By Operator
- Maintenance’s Start-Up Electrical & Instrument Specialist - Maintenance’s Start-Up Machinist
- Maintenance’s Start-Up Fitter - Power Distribution Department - Fire Prevention
- Loss Prevention
- Process & Control Systems Department - Computer, Communications and Office Systems
NOTE 1: Construction Agency is responsible for performing all work prior to Mechanical Completion, unless assigned otherwise as indicated with an X.
NOTE 2: Per paragraph 4.3.1.6 of G.I.2.710, Construction Agency will provide an agreed number of Contractor
Commissioning Assistance Personnel to work under the direction of the Proponent Commissioning Supervisor or his Nominee. Alternatively, and as directed by Proponent, Operations/Commissioning will utilize E&I, P or PDD personnel for Commissioning Assistance.
NOTE 3: PDD will inspect and sign-off for all Power Distribution Systems above 480V; 480V and below will be inspected by Project Inspection and witnessed by Operations/Commissioning.
NOTE 4: Minimum of 10% of Megger Testing to be witnessed, balance to be monitored.
NOTE 5: Routine cleaning/flushing to be witnessed by Inspection and reviewed by Commissioning. All other specialty cleaning (lube oil systems, etc.) to be witnessed by Commissioning.
GI 2.710 Excerpt Figure 23
WORK AID 2 (Cont'd)
DIVISION OF RESPONSIBILITIES FOR TURNOVER SUPPLEMENT NO. 2.710-6
MECHANICAL
COMPLETION STARTUP
(Pre-Turnover) (Post-MCC)
Project
Inspection Operations/
Commissioning
Commissioning with Constr.
Agency (Note 2) Proponent
3. ELECTRICAL
a. Perform dielectric strength tests on power
transformer and disconnect switch insulating oil and install when satisfactory.
b. Check condition of grease in grease lubricated motor and generator bearings.
c. Perform all necessary prestart-up non-operating tests and Hi Pot checks on all power cables, generators, Switchgear, MCCs, transformers and grounding resistors following manufacturers’
instructions and guidelines given in the applicable Saudi Aramco Pre-Commissioning Forms Manual available from Consulting Services Department.
d. Measure and record the insulation resistance (Megger Testing) of all power (480 V or less), instrument wiring (including thermocouple leads) and lighting circuits from conductor to conductor and from each conductor to ground.
e. Perform applicable checks, adjustments and field tests using, if necessary in order to maintain schedule, temporary construction power.
f. Calibrate and set substation relays on all circuit breakers. Set time delays. Set and test fault pressure relays and transformer taps.
g. Energize substations and load centers by connection to electrical distribution systems (Energized by authorized electrical systems operator after obtaining approved “Energization Authorization Certificate”).
h. Check operability of emergency and instrument power systems as well as emergency lighting system.
i. Issue work permits to Contractor for carrying out checks on electrical equipment, after facilities are energized per item (g) if partial MCC signed.
j. Paint or tag all electrical apparatus (Push button boxes, connection boxes, etc) according to Saudi Aramco’s color code or regulations.
k. Construction Agency will use existing established work permit procedure for remaining construction period, once electrical equipment is energized. (If the existing Tag and Lock-Out Procedure needs to be revised, it shall be approved by Loss Prevention
I
GI 2.710 Excerpt Figure 23 (Cont'd)
WORK AID 3:REFERENCES FOR EVALUATING MEDIUM/HIGH VOLTAGE