FAQ

 

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Connectors

Bushings

Surge arresters

Terminations

Joints

Contacts

faq

Connectors

Q: Are the Euromold connectors halogen free?

A: Yes, the Euromold connector and all its components are made of halogen free material.

Q: Are the Euromold connectors water tight?

A: Yes, the Euromold connectors are completely watertight, both at the interface and at the cable entrance. In case of Cu wire screen, water sealing mastic is applied on the cable jacket.

Q: Can the Euromold connector be immediately energised after installation?

A: Yes, the Euromold connector is ready to be energised immediately after installation.

Q: How can  you see if a switchgear is earthed?

A: MV switchgear is usually equipped with voltage indicators, indicating whether the switchgear is switched off and earthed and thus safe to disconnect the cables - It can be checked also by measuring at the capacitive test point of the connector - In case of a transformer, the capacitive test point of the MV connector can be measured or otherwise the connection at the LV side. In any case the safety regulations according to the applicable national standards should be respected before taking any action to touch or disconnect the equipment.

Q: How is a Euromold connector made?

A: The housing of a Euromold connector is moulded in three steps: 1. Jacket, 2. Insert, 3. Insulation in between jacket and insert.

Q: Is it safe to remove the cap of the Capacitive Testpoint?

A: It is safe to remove the cap of the capacitive testpoint and to accidentally touch it without protection. The overall available energy is minimal, any potential will disappear immediately when touched by an operator. Because the VD-point has a high impedance, the current transfer is a fraction of a micro ampère and imperceptible to human touch. However, according to the procedures of all Power Utilities, intended manipulation of the connectors should be done with hot stick, insulated pliers or other appropriate tools.

Q: Of which material are the cable adaptors such as 211CA, 411CA, 430CA made?

A: The cable adaptors are made of a compound with high permittivity factor. This provides electrical stress relief at the semicon cut-off point of the cable. Because the cable adaptors are not conductive, they provide a screenbreak between the cable and the connector housing. So the cable screen can be tested without disconnecting the connector from the equipment.

Q: What are the advantages of EPDM connectors compared to silicone connectors?

A: Amongst other advantages, the EPDM connectors have a higher mechanical strength and can be easily connected and disconnected from the bushing. The silicone connectors tend to stick to the bushing and cannot be removed easily without damaging the connector.

Q: What does MWS stand for?

A: MWS stands for Mastic Water Sealing and is included in connector kits for outdoor use. The mastic is installed on the jacket under the bent-back Cu wire screen, to provide watersealing.

Q: What is a deadbreak connector?

A: The Euromold connectors are deadbreak connectors. The power has to be switched off before the connector can be disconnected from the bushing.

Q: What is a loadbreak connector?

A: The connector can be pulled from the equipment with an insulating stick while the cable is still under tension.

Q: What is blooming of the rubber connectors?

A: After a long time, talc powder (which is mixed in the rubber mixture) can rise to the surface of the connectors and form a white "layer" on the connectors - this layer can be easily cleaned and will not harm the connector's normal functioning.

Q: What is EPDM, material of the Euromold separable connector?

A: EPDM stands for Ethylene Propylene Diene Monomer rubber. The outer jacket and insert of the connector are semi-conductive. The material in between these two layers is insulating EPDM.

Q: What is the difference between a kit called 3X430TB and a kit called T-430TB?

A: Both kits contain 3pcs of 430TB connector, but the 3X430TB contains installation instructions for single core cable and the T-430TB contains installation instructions for 3-core cable.

Q: What is the function of a separable connector?

A: To connect MV cable to equipment, such as transformers, switchgear, motors and generators.

Q: What is the function of the bail restraint?

A: Keep the connectors with pin-contact (Interface A and Interface B) in place during short-circuit situations.

Q: What is the IP rating of the Euromold connector?

A: The IP (Ingress Protection) rating of the Euromold connectors is IP67. This means that the connectors are completely dust-tight and suitable for immersion in water of <1m depth.

Q: What is the resistance of the Euromold connectors to harsh environments?

A: The material of the Euromold connectors is resistant to UV radiation, ozone, sunlight, pollution such as salt-fog, heavy industry environments such as steel and cement works etc.

Q: What is the shelf life of the Euromold connectors?

A: The Euromold connectors have unlimited shelf life when stored in good conditions (no direct sunlight, no dust,…)

Q: What is the temperature range of the Euromold connectors?

A: The temperature range in which a Euromold connector can operate is from -60°C to +130°C. Because of the temperature range of the epoxy bushing, the actualtemperature range for the application is from -40°C to +115°C.

Q: What is the use of the test rods such as 400TR, 800TR,… ?

A: The test rods can be installed at the back of a T-connector or elbow connector and are used for cable fault location, cable testing, phasing checks and earthing.

Q: Where does the cable clamp needs to be installed?

A: As close as possible to the connector without damaging the connector. Make sure the cable is straight when clamped. Best is to clamp the cable first and then install the connector on the bushing.

Q: Which is the main component of the surge arrester?

A: The surge arrester contains metal oxide blocks which act as varistors.

Q: Why can't the 400TR be used for testing of M-products (75kV AC - 50Hz - 1')? Why is it limited to 36kV AC - 50Hz - 1'?

A: The concept of a test rod has been made to allow the network to apply a tension on the cable so one can check the “health” of the system (so called “after-laying tests”, fault location, etc.). This AC voltage is limited to 2U0 to avoid that any damage is done by the test itself (in the past there were also DC tests, but these have been replaced in most cases by VLF tests at 2U0 or 3U0).
The straight forward design of the test rod (no stress grading components, limited interference, no screening) does not allow that high voltages (as required in the normal qualification programs) are applied. And as explained above this has in fact never been the objective of these test rods.

Q: Why does the 400BIPA has to be tightened with a torque of 50Nm and the 300BIPA with a torque of 30Nm?

A: The 400BIPA and 300BIPA need different tightening torque, because there is a difference in design. The 400BIPA is in contact with the contact palm. This requires a higher torque value than for the 300BIPA which is in contact with the clamping screw.

Q: Why is a Euromold separable connector safe to touch?

A: Because of the 3mm thick semi-conductive layer, which is connected to earth, the Euromold connectors are safe for accidental touching. This can be for a short or long time. According to the procedures of all Power Utilities, intended manipulation of the connectors should be done with hot stick and other appropriate tools.

Q: Why is there no test rod available for Interface A?

A: The design of the test rod is such, that it needs to be in contact with the conductor of the cable. This is possible for T-connectors, and for Elbow connectors with a removable plug. This is not possible for Interface A connectors.

Q: What is the function of the 11TL adaptor?

A: Together with the watersealing mastic, the 11TL provides the water tightness of the connector at the cable entrance. It also provides a step for easy positioning of the connector.

 Bushings

Q: Are Euromold bushings deadbreak or loadbreak bushings?

A: Euromold bushings are deadbreak bushings. The power has to be switched off before the connector can be disconnected from the bushing.

Q: Is a PITO-E suitable for outdoor use?

A: Yes, a PITO-E is suitable for outdoor use in medium polluted atmosphere.

Q: What is a PITO-E?

A: A PITO-E is a plug-in termination, enabling to connect overhead lines or busbars to an Interface A epoxy bushing.

Q: What is an in-air bushing?

A: The shaft of an in-air bushing does not need to be immersed in oil. The creepage length over the surface is long enough to install it in air and the epoxy material is resistant to UV light.

Q: What is the difference between epoxy bushing and porcelain insulator?

A: The Euromold epoxy bushings can be connected to screened separable connectors, providing a screened safe-to-touch connection. Porcelain insulators can be connected with terminations, which are open connections and thus not safe-to-touch and require larger clearance distances.

Q: What is the function of a bushing?

A: Bushings are devices designed to transmit electric energy through a grounded barrier, such as the wall of a transformer or switchgear. The Euromold epoxy bushings provide an insulated and screened connection between the conductors in the equipment and conductor of the cable.

Q: What is the maximum number of cables which can be connected to a bushing?

A: The maximum number of cables which can be connected to a bushing, depends on the maximum allowed current, on the stability of the arrangement and on the type of interface. Interface A and B have a plug-in interface so maximum one cable can be connected in a normal arrangement because a bail restraint is needed to hold connector in place, multiple cable arrangement for these interfaces are only possible with 200T- or 200X-connectors. For other interfaces such as Interface C, a multiple connections such as P2, P3, P4, ... are possible.

Q: What is the maximum torque for the fixing studs holding the bushing clamp?

A: The maximum torque for the fixing studs is not officially specified, but we recommend maximum 16Nm for M10 and maximum 25Nm for M12 studs.

Q: What is the temperature range of the Euromold epoxy bushings?

A: The temperature range in which a Euromold bushing can operate is from -40°C to +115°C.

 Surge arresters

Q: How does the Euromold surge arrester work?

A: In normal conditions SA has a high resistance R, when overvoltage occurs (lightning, switching, …) resistance R of the SA will drop until it is smaller than the resistance of the network and failure current will be led through the SA out of the network.

Q: How to see if a surge arrester is at end of life?

A: The temperature of the surge arrester will rise. This can be checked with an infrared camera.

Q: Should the surge arrester be installed in front or at the back of the Euromold connector?

A: This makes no difference electrically. The most common installation is with the surge arrester installed at the back of the Euromold connector. Important is that the cable is properly clamped so bushing has only to carry the weight of the connector and the surge arrester.

Q: What is the function of the Euromold surge arrester?

A: To protect the transformers, switchgear, cables and accessories from HV surges (due to lightning or switching).

 Terminations

Q: What is the difference between indoor and outdoor terminations?

A: The creepage distance over the surface of the terminations is longer for outdoor terminations than for indoor terminations. This can be achieved by a greater length and by the use of sheds.

Q: What is the meaning of P in the AFN-P terminations?

A: For application in (heavy) Polluted areas - Creepage length is 1079mm (30mm/kV) whereas for standard AFN's the creepage length is 755mm (21mm/kV)

Q: What is the function of a Termination?

A: Restore the insulation and provide stress controll at the semicon cut-off point of the cable (which is connected to equipment with a cable lug). A termination is an unscreened, not touchable connection. Minimum clearance distances have to be respected.

Q: What is the required storage temperature of coldshrink products?

A: The coldshrink products should be stored at a temperature between -10°C and +40°C.

Q: What is the shelf life of coldshrink products?

A: The shelf life of the Nexans coldshrink products is 2 years. After two years the elasticity has not changed, only the speed of retraction is less.

Q: What is the shelf life of heatshrink products?

A: The Nexans heatshrink products have unlimited shelf life if stored in good conditions (no direct sunlight, no dust,… ).

Q: What is the difference between an ITK and AIN termination?

A: The ITK is a coldshrink termination with mastic providing the stress control. The AIN is a slip-on or push-on termination, with a stress cone providing the stress control.

Q: What is the required environmental temperature during the installation of coldshrink products?

A: The required environmental temperature during the installation of coldshrink products is between +5°C and +40°C. In colder circumstances the product can still be installed, but it will take more to reach the final diameter.

 Joints

Q: What is the function of a joint?

A: The function of a joint is to connect two cables to each other. The several functions are a.o. connecting the conductor, providing stress control at the semi-con cut-off point of the cable, keeping the electrical field inside of the joint, reinstalling the insulation and providing a screen connection.

Contacts

Q: What is the current limit for TBC contacts?

A: TBC-X-10-1 and TBC-X-10-2 contacts are qualified for 630A, all other contacts are qualified for 1250A, but maximum countinuous current depends also on the cross-section of the cable.