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How To Carry Out A 230kV Pipe Type Pothead Replacement /Cable Freeze

• uploaded by Chris Dodds - Sales & Marketing Manager | Thorne & Derrick
  
  

  All Images Courtesy Of: Douglas Page (Instructor & Cable Splicer at Hydro One Training and Development Services).

  

Douglas Page is not a stranger to our Jointers Blog having blazed a trail over the past few weeks with some real ripsnorting, hardcore, high voltage images.

Let’s treat ourselves to a quick whistlestop tour of Doug’s recent contributions to the Jointers Blog as an appetite whetter to the latest serving up of his captivating EHV skills.

 ➡ See Also: How To Find A Single Drip Of Oil In Approximately 12km Of LPOF PILC 115KV Direct Buried Cable

115kV Straight & Stop Joint On LPLF, PILC Cables In Cable Vault

EHV Cable Splicing – 115kV Stop Joint (Taped)

Jointing 44kV High Voltage Submarine Cables Using 3M Cold Shrink Splices

Water Treeing in High Voltage Cables : A 230kV HPPT Termination Repair

Time for the Main Course. Bon Appetit…

The following are the steps involved to replace the insulator on a 230kV pipe type cable.

1. All of the insulation (rubber and compound) must be removed from the single conductor stainless steel pipe

2. Once the single conductor goes underground, it goes to a trifurcating cable splice, and then the three conductors are in one pipe

3. With the pipe exposed the jointer starts wrapping the the copper tube

4. Continue to wrap, leaving a space in the middle and then duplicate the first section of wrap

5. Once all the tubing is applied, thermocouple probes are placed at the middle and both “outside” points of the freeze to monitor temperature, and a moisture barrier is applied

6. Heavy duty pipe insulation is installed (several layers)

7. With the wrap completely installed, another moisture barrier is applied

8. Before the freeze can be initiated, the oil pressure must be greatly reduced, to just above ‘static’ pressure, or the constant force of the oil would prevent the cable from freezing

9. Depending on pipe size, conductor size, length of pipe, time of year, once the liquid nitrogen is applied, it takes various amounts of time to freeze any particular cable. All three thermocouples are constantly monitored

10. With the desired temperature reached, the freeze plug is active. The termination (pothead) is drained, and the old insulator is removed

11. The cable termination is meticulously inspected and cleaned. Flushed several times with hot cable oil

12. The new porcelain is installed

13. Once the new glass is bolted back on to the cable and sealed, the Liquid Nitrogen can be shut down, and the cable begins to thaw

14. Once cable has thawed the cable termination (pothead) is slowly filled with cable oil, under vacuum

THORNE & DERRICK

Thorne & Derrick are national distributors of LV, MV & HV Cable Installation, Jointing, Substation & Electrical Equipment – servicing businesses involved in cabling, jointing, substation, earthing, overhead line and electrical construction at LV, 11kV, 33kV, 66kV and EHV. Supplying a complete range of power cable accessories to support the installation and maintenance of low/medium and high voltage voltage power systems:

• Slip-on Cable Terminations
• Cold-shrink Cable Terminations
• Heat-shrink Cable Terminations
• Cable Joints – Heat & Cold-shrink
• Separable Connectors (Euromold)
• Surge Arresters & Switchgear/Transformer Bushings

Key Product Categories: Duct Seals | Cable Cleats | Cable Glands | Electrical Safety | Arc Flash Protection | Cable Jointing Tools | Cable Pulling | Earthing | Feeder Pillars | Cable Joints LV | Joints & Terminations MV HV 

How To Find A Single Drip Of Oil In Approximately 12km Of LPOF PILC 115KV Direct Buried Cable

• uploaded by Chris Dodds - Thorne & Derrick Sales | Marketing Manager

All Images Courtesy Of: Douglas Page (Instructor & Cable Splicer at Hydro One Training and Development Services).

Fluid Filled Cables

Fluid filled high voltage cables have been used for over 80 years with some circuits installed in the 1930’s still operating successfully today without any deterioration.

The fluid contained within a fluid filled cable has to be kept at a positive pressure under all conditions of loading and ambient temperature change.

Fluid filled cables rely on the presence of pressurised cable fluid to work efficiently – if the circuit suffers an oil leak the cable network is compromised.

The pressure used depends on a number of factors:

• Voltage and size of cable
• The length of the cable
• The route the cable follows
• Whether the cable has a leak

High Voltage Cables

The fluid forms an integral part of the high voltage cable insulation and prevents the formation of voids in the lapped papers around the conductor – also the cable fluid aids the conduction of heat away from the conductor allowing the cable to be run efficiently than a cable without it.

The following photo sequence shows how to find a single drip of oil in approximately 12km of Single Core LPOF PILC 115KV direct buried cable.

LPOF Low Pressure Oil Filled
PILC Paper Insulated Lead Covered

1. Cathodic lead erosion is clearly visible on the EHV power cable – this is usually caused by ground factors such as gas mains, neighbouring cable circuits, water mains etc. The aged underground EHV cable is suffering natural degradation and overtime a deterioration in the cables normal cathodic protection has caused service issues with the cable circuit – the cable becomes the sacrificial anode and starts to break down.

2. Cable type : Transmission & Distribution Voltage – 115kV LPOF PILC Single Core.

3. LPOF EHV cables are monitored by gauges and pressurized by pre-pressurized tanks with internal baffles, that expand and contract with the cable, maintaining a constant pressure. If the pressure cannot be maintained, an alarm is triggered.

4. To find the oil leak in 10, 15, 20, or 100km of cable, it all starts the same way. Find the approximate centre of the cable circuit, excavate safely and install a cable freeze.

5. Very similar to a pipe type freeze, the coil must be installed on the bare lead.

6.

7. Along with a freeze, to monitor the temperature, the EHV jointer/splicer must install thermocouple temperature monitors which consist of two conductors of dissimilar metals that react to the temperature change differently allowing the monitors to display the actual temperature. 

8.

9.

10. Once the freeze has been initiated, the gauges are monitored, the side that loses pressure, is flagged and deemed the side that requires further attention

11. Freeze pit – once the leak has been narrowed to 50-100m length, the final excavation begins. Until signs of leaking cable oil are found

13. After a lengthy search, this is what you are looking for, although opinions vary, constant drip can yield various amounts of accumulation. Some say it could fill a bathtub in 72 hours

14. Once located a temporary EHV cabl repair is made, while environmental remediation is done

15. “Tinning” of the cable repair, so the lead will adhere to the cable

16. The EHV cable repair is complete – after this the jointer must solder a copper lead connected to a sacrificial “anode” that erodes before the cable

Further Reading

• How To Carry Out A 230kV Pipe Type Pothead Replacement /Cable Freeze

THORNE & DERRICK

Thorne & Derrick are national distributors of LV, MV & HV Cable Installation, Jointing, Substation & Electrical Equipment – servicing businesses involved in cabling, jointing, substation, earthing, overhead line and electrical construction at LV, 11kV, 33kV, 66kV and EHV. Supplying a complete range of power cable accessories to support the installation and maintenance of low/medium and high voltage voltage power systems:

• Slip-on Cable Terminations
• Cold-shrink Cable Terminations
• Heat-shrink Cable Terminations
• Cable Joints – Heat & Cold-shrink
• Separable Connectors (Euromold)
• Surge Arresters & Switchgear/Transformer Bushings

Key Product Categories: Duct Seals | Cable Cleats | Cable Glands | Electrical Safety | Arc Flash Protection | Cable Jointing Tools | Cable Pulling | Earthing | Feeder Pillars | Cable Joints LV | Joints & Terminations MV HV 

Introducing Pleavin Power | 24/7 Generator Specialists

Pleavin Power

Pleavin Power is a leading generator specialist that provides solutions, maintenance, sales and hire to customers across the UK. We can ensure that your operations can continue in the event of mains power failure. Pleavin Power have expertise in agriculture, construction, data centres plus many more, have a look below for all the sectors we work with.

• Agriculture
• Construction
• Contracting
• Data Centres
• Facilities Management
• Food & Beverage
• Government & Military
• Manufacturing
• Mining
• Offshore Oil & Gas
• Petrochemical & Refining
• Pharmaceuticals
• Pumping Station
• Rail
• Renewables
• Shipping & Marine
• Telecommunications
• Utilities

For all of our new and existing customers, here’s just some reasons why you can rely on Pleavin Power.

Pleavin Power

WHY CHOOSE US?

Pleavin Power is built on reputation.

From the generators we sell to the engines we service, we care because our names on it, our name means business and when our clients call upon us we have never failed to deliver.

Pleavin Power operate a reactive workforce specialising in emergency support and disaster recovery around the clock.

From the minute you call, to the second we leave, we’ll be with you every step of the way. Specialising in:

Control Systems

As an alternative to purchasing a completely new power system, an option is to upgrade or refurbish an existing system. Our experienced in-house team ensures that any system upgrade is trustworthy and continues to produce a reliable power flow.

Transformer Hire

With the need for constant power and an ever-increasing requirement, an out of commission generator or the failure of the mains power supply, can develop into a major situation.

Decommissioning

We also offer support on new installations, complete design and service, commissioning and decommissioning, repairs, spares and site surveys. To find out more about our additional UPS solutions, get in touch.

Same Day Solutions

One call to the Pleavin Power emergency line (0800 689 4803) will give you peace of mind that immediate assistance is on the way – 24 hours a day, 7 days a week, 365 days a year.

As well as:

• Fault Finding
• Final Connections
• Generator Servicing
• High Voltage Connections
• Load Banking
• Out Of Hours Servuce
• Repairs
• Temp Systems
• USP Hire

Pleavin Power Clients

Pleavin Power Clients

What else do Pleavin Power Offer?

• EMERGENCY RESPONSE – We have set up a national emergency response telephone line, manned by experienced staff. A call to our emergency line will give you peace of mind that immediate assistance is on the way – 24 hours a day, 7 days a week, 365 days a year
• RELIABILITY AND AVAILABILITY – The combination of our highly-skilled and accredited team, along with our wide range of equipment and components, means we can offer a reliable service to you with quick product dispatch when you need help most
• DESIGN AND CONSULTANCY – With solutions available from 10kVA to 30mVA, we can offer our clients a range of complete turnkey power solutions. Our in-house design department works with you to identify, install and test the best solution for you
• INSTALLATION AND PROJECT MANAGEMENT – Using our quality assurance systems, we can install, and fully project manage your new power solution to the exacting controls and standards required. We will also endeavour to be economical to procure, deliver, install and maintain
• SERVICE AND MAINTENANCE – We want to ensure that your power system is working at all times and ready to provide back-up supply. Therefore, we have created a range of service and maintenance programmes to keep your system in good order at all times
• SOURCING AND SUPPLY – With supply agreements secured with a wide range of international manufacturers, you can be confident of receiving the right solution for you. All our spare components also meet the manufacturer’s OEM specification
• WHOLE LIFE ASSET MANAGEMENT – Throughout the life of your power solution, we can offer all customers an asset management solution to help maintain the integrity of your back-up supply
• 24/7/365 – Continuous support is offered 24/7 through a nationwide base of field engineers who can be on site in the event of emergencies just about anywhere in the UK – often within 4 hours and backed up by a national supplier database
• SECTOR EXPERTISE – From large UK-based data centres to hospitals, banks and utility company’s headquarters, we have helped a wide range of sectors with their critical power supply solutions – giving us experience in solving any problem that comes our way

Pleavin Power introductory

Video describing Pleavin Power’s power generation business & operations

Contact Pleavin Power

Unit 12, The Arena, Stadium Court, Stadium Road, Bromborough, CH62 3AE

+44(0)800 689 4803

[email protected]

THORNE & DERRICK

Thorne & Derrick are national distributors of LV, MV & HV Cable Installation, Jointing, Substation & Electrical Equipment – servicing businesses involved in cabling, jointing, substation, earthing, overhead line and electrical construction at LV, 11kV, 33kV, 66kV and EHV. Supplying a complete range of power cable accessories to support the installation and maintenance of low/medium and high voltage power systems:

• Slip-on Cable Terminations
• Cold-shrink Cable Terminations
• Heat-shrink Cable Terminations
• Cable Joints – Heat & Cold-shrink
• Separable Connectors (Euromold)
• Surge Arresters & Switchgear/Transformer Bushings

Key Product Categories: Duct Seals | Cable Cleats | Cable Glands | Electrical Safety | Arc Flash Protection | Cable Jointing Tools | Cable Pulling | Earthing | Feeder Pillars | Cable Joints LV | Joints & Terminations MV HV 

Waveform Straight Joint – 3 Core 185sqmm – 95sqmm Cables

• Application: Waveform Straight Joint – 3 Core 185sqmm – 95sqmm Cables
• Cable Type: Wavecon Straight Joint
• Cable Jointer: Damien Davis
• Photo By David Lane Technical Trainer UKPS

Waveform Straight Joint

Thorne & Derrick are Specialist Distributors to the UK Distribution Network Operators and ICP sector providing Waveform Cables, Accessories & Electrical Equipmentfor LV MV & HV Networks – the DNO approved cables are installed for adoptable networks and contestable connections on following DNO’s: Northern Powergrid (NPG), ENW (Electricity North West), Western Power Distribution (WPD), Scottish Power Energy Networks (SPEN), Scottish & Southern Energy (SSE) and United Kingdom Power Networks (UKPN).

Typical common aluminium conductors from stock are 95sqmm, 185sqmm and 300sqmm.

Waveform cables are XLPE insulated and PVC sheathed power cables used for the supply of LV electrical energy 600/1000V – cables are suitable for installations in the open air, in underground and water, indoor and in cable ducts. The concentric conductor is allowed for use as neutral, protective or earthed conductor.

Waveform Straight Joint – 3 Core 185sqmm – 95sqmm Cables

Waveform Cable Accessories

T&D UK distribute an extensive range of low voltage utility waveform power cables including cable joints, cable cleats, cable glands and accessories required to lay and install waveform cables to BS7870.

Thorne & Derrick Specialist Electrical Distributor

LV ♦ MV ♦ HV

T&D distribute the most extensive range of LV, MV & HV Cable Jointing, Terminating, Installation & Cable Pulling Equipment – we service UK and international clients working on underground cables, overhead lines, substations and electrical construction at LV, 11kV, 33kV and EHV transmission and distribution voltages.

• Key Products: MV-HV Cable Joints & Terminations, Cable Cleats, Sealing Cable Ducts, Cable Transits, Underground Cable Protection, Cable Jointing Tools, Feeder Pillars, Cable Ducting, Earthing & Lightning Protection, Electrical Safety, Cable Glands, Arc Flash Protection & Fusegear.

• Distributors for: 3M, ABB, Alroc, Band-It, Catu, Cembre, Centriforce, CMP, Elastimold, Ellis Patents, Emtelle, Furse, Lucy Zodion, Nexans Euromold, Pfisterer, Polypipe, Prysmian, Roxtec.

LV – Low Voltage Cable Joints, Glands, Cleats, Lugs & Accessories (1000 Volts)

MV HV – Medium & High Voltage Cable Joints, Terminations & Connectors (11kV 33kV EHV)

Cable Laying – Underground Cable Covers, Ducting, Seals & Cable Pulling Equipment

More…

T&D’s Power Blog covers: LV MV HV & EHV Transmission & Distribution, Substations, Switchgear, Cable Jointing & Termination, Cable Fault & Repair, Underground Cables.

arrow: Visit Power Blog

LV Cable Diversion 4 Core PILC to 4 Core Wavecon Straight Joint

• Application: LV Cable Diversion 4 Core PILC to 4 Core Wavecon Straight Joint
• Cable Type: Wavecon Straight Joint
• Cable Jointer: Lee Richards Self Employed Cable Jointer

Jointing Waveform Cables

Here Lee Richards is shown carrying out some LV cable diversions for a private network customer – the installation required 4 x PILC to 4 core Wavecon joints and the cable jointing was assisted by Simon Pearson (Freelance HV SAP Electrical Engineer).

Thorne & Derrick Specialist Electrical Distributor

LV ♦ MV ♦ HV

T&D distribute the most extensive range of LV, MV & HV Cable Jointing, Terminating, Installation & Cable Pulling Equipment – we service UK and international clients working on underground cables, overhead lines, substations and electrical construction at LV, 11kV, 33kV and EHV transmission and distribution voltages.

• Key Products: MV-HV Cable Joints & Terminations, Cable Cleats, Sealing Cable Ducts, Cable Transits, Underground Cable Protection, Cable Jointing Tools, Feeder Pillars, Cable Ducting, Earthing & Lightning Protection, Electrical Safety, Cable Glands, Arc Flash Protection & Fusegear.

• Distributors for: 3M, ABB, Alroc, Band-It, Catu, Cembre, Centriforce, CMP, Elastimold, Ellis Patents, Emtelle, Furse, Lucy Zodion, Nexans Euromold, Pfisterer, Polypipe, Prysmian, Roxtec.

LV – Low Voltage Cable Joints, Glands, Cleats, Lugs & Accessories (1000 Volts)

MV HV – Medium & High Voltage Cable Joints, Terminations & Connectors (11kV 33kV EHV)

Cable Laying – Underground Cable Covers, Ducting, Seals & Cable Pulling Equipment

More…

T&D’s Power Blog covers: LV MV HV & EHV Transmission & Distribution, Substations, Switchgear, Cable Jointing & Termination, Cable Fault & Repair, Underground Cables.

arrow: Visit Power Blog