ADVANCED POWER ANALYTICS LIMITEDOnyx Group - HV installation Test Report
Client - OnyxDocument Prepared by - Ron Richardson (On behalf of Keysource)
Document Date - 02/05/2012
Table Of Contents! ! 1.0 - Installation Report Overview 3
2.0 - Testing Operation Schedule 6-7
3.0 - HV Testing
3.1 - HV Terminations
3.1.1 - HV Feed to TX1 9
3.1.2 - HV Feed to TX2 10
3.1.3 - Scottish Power Incomer Number 1 11
3.1.4 - Scottish Power Incomer Number 2 12
3.2 - HV Switchboard
3.2.1 - HV Pressure testing of Busbars & Switchgear 13
3.2.2 - Ductor Testing of HV Busbars 14
3.3 - HV Pressure Testing theory
3.3.1 - Pressure testing @ 25KV 15
3.3.2 - Pressure testing @ 18KV 16
3.4 - Transformer Testing
3.4.1 - Transformer No.1 17
3.4.2 - Transformer No.2 18
4.0 - Recommendations 20
1 - HV Report Overview
The following report has been produced to help give clear indication of the testing procedures and the respective results of the tests that were necessary for
the successful implementation of the new HV Substation which has been installed at the Onyx Group data centre (Edinburgh)
Switchgear & Transformer Testing:
Due to the existing configuration (RMU ‘close-coupled’ to the Transformer) in order to carry out the testing of the Transformer it would be necessary to
disconnect the ‘new’ previously installed HV termination at the RMU and then use the switching ‘on’ positions to test through the switches onto the HV
windings of the Transformer. The HV test voltage values and durations would then have to be considered to ensure no possibility of ‘Over-stressing the HV
Equipment. Functional Switching Checks were also carried out to confirm Switching operation reliability.
Secondary protection tests were also carried out to check that the Switchgear would operate under fault conditions as well as Insulation resistance checks for
the Current Transformers
Method Statements and Risk assessments were constructed prior to the work commencing highlighting the Process and Immediate risk(s) in connection with
the tasks.
The equipment tested was subjected to the following electrical tests consisting of :
1 - Pre and post Insulation resistance testing @ 5KV
2 - Uni-polar HV Testing @ 18 - 25KV (for 1 min & 15min durations)
3 - Secondary Injections Currents (0 - 20 amps) for Trip Testing Simulations
4 - Ductor testing Currents (50 & 100 amps) for testing the HV Busbars
*Important Notes -
1 - Any recorded values lower than 75 Mega Ohms for Transformer tests will need to be reported to the manufacturer prior to any Energization activity as this
may representative of a potential Failure.
2 - Any HV Cables tests with Insulation resistance values lower than 500 Mega Ohms prior to Energization will be subject to further investigation works as this
may again be representative of imminent or possible near future Failure.
2 - Testing Operation Sheets
3 - HV Testing (Switchgear & Cables)
3.1.1 - HV Cable feed to TX1
3.1.2 - HV Cable feed to TX2
3.1.3 - Scottish Power Incomer No.1
3.1.4 - Scottish Power Incomer No.2
3.2.1 - HV Busbar Testing (Insulation Resistance & Pressure Testing)
3.2.2 - HV Busbar Testing (Ductor Testing)
This figure is 2x the RMS value and is used to theoretically simulate some of the 'in rush currents that are associated at the point of energisation.
Peak Value
11000 √3
Value = 1.732
This figure is used to establish the voltage in any individual 'phase
Root 3
This figure is the system voltage, and is the phase to phase value that the cable/switchgear is subjected to
System Voltage
6351 x 1.414 x 2.55 x 1.1
25185 voltsTest value = 25 KV (Per Phase - DC Test)
x 1.414 x 2.55 x 1.1
11000 1.732
x 1.414 x 2.55 x 1.1
This figure takes is the nominal voltage based on 10% more than the system voltage (11 KV)
Nominal voltage
1 - Insulation resistance test results should be greater than 10 gig ohms when testing each individual core to earth as well as phase to phase testing.2 - Insulation resistance tests that are less than 10 gig Ohms will result in further inspection of the cable installation for any possible causes.3 - If there is a large variation in core test results when carrying out insulation resistance tests then further investigation will be required.
Additional notes (For new cables)This figure takes into consideration the transient voltage at the peak of the sinewave
Transient Voltage
3.3.1 - HV Pressure Testing Theory (25 KV)
This figure is 2x the RMS value and is used to theoretically simulate some of the 'in rush currents that are associated at the point of energisation.
Peak Value
11000 √3
Value = 1.732
This figure is used to establish the voltage in any individual 'phase
Root 3
This figure is the system voltage, and is the phase to phase value that the cable/switchgear is subjected to
System Voltage
6351 x 1.414 x 2
17960 volts
Test value = 18 KV (Per Phase - DC Test)
Cable test theoryDue to the nature of the installation it is deemed that the cable under test is an 'old' cable because it would have been subjected to factory tests. The test value used in this instance is a value that takes this into consideration as well as the fact that there will be certain impulse values which can be 2 or 3 times the Peak value. Each phase of the cable will be tested individually with the other phases earthed for a duration of 1 min. This test will be a DC Test.
x 1.414 x 2
11000 1.732 x 1.414 x 2
1 - Insulation resistance test results should be greater than 10 gig ohms when testing each individual core to earth as well as phase to phase testing.2 - Insulation resistance tests that are less than 10 gig Ohms will result in further inspection of the cable installation for any possible causes.3 - If there is a large variation in core test results when carrying out insulation resistance tests then further investigation will be required.
Additional notes (For new cables)
This figure takes into consideration the peak value which can be 2 or 3 x the peak value when the cable is energised
Peak multiple factor
3.3.2 - HV Pressure Testing Theory (18 KV)
3.4.1 - Transformer No.1 Testing
3.4.2 - Transformer No.2 Testing
4 - Recommendations
The following items listed below are recommended future works that we feel are necessary to ensure the system resilience for the current and future power
demands the Data centre will be subjected to:
1 - Full HV/LV Protection Study:
It is recommended that a full Protection study including the current and future HV equipment is carried out so that the data centre can run with the maximum
level of safety.
2 - Thermal imaging of new and existing infrastructure:
Thermal imaging will help gauge an understanding of the system performance with respect to system efficiencies and help identify equipment which emit
excessive heat which equate to power losses.
3 - Detailed Power Supply Audit (HV &LV):
APA Ltd can conduct a detailed power audit which differs from the conventional approach in that:
a) We will identify the losses within the system using multiple approaches.
b) We will identify how the problems (if any) came into existence.
c) We will accurately determine what the costs of the inefficiencies are with respect to money.
d) Provide realistic tangible solutions for the client starting with looking at ways to re-managing the existing power infrastructure.
4 - Asset Maintenance:
We recommend that a planned maintenance program is constructed with respect to the HV supply and Heavy current LV equipment which can be factored in at
the most convenient times suitable to the client.
No.8 Bank Apartments, Marlow, Buckinghamshire, United Kingdom SL7 3DXMobile - +44 7515 384458
email - [email protected]
Advanced Power Analytics LimitedInstallation Services: HV & LV Cable Jointing up to 33 KV HV & LV Construction Up to 33 KV Protection Testing / Grading Surveys Full HV and LV Commissioning
Maintenance & Analysis (Online & Offline) HV & LV Maintenance Up to 132 KV Power Quality Analysis / Power Auditing Thermal Imaging Ultrasonic Testing Partial Discharge Testing
Additional Services: Technical Consultancy Technical Media Development Asset Management Project Management Training (On site and system specific)
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