Cast Resin Transformers Installation, use and maintenance manual

Cast Resin Transformers

Cast Resin Transformers 3.1 Conditions for the correct operation of the transformer 4 Transport, receipt and storage 5.1.1 Installation in protection enclosure 5.1.2 Installation without protective enclosure (IP00) 5.1.3 Examples of wrong installation 5.2 Connections on the Low Voltage side - LV 5.3 Connections on the High Voltage side - HV 5.4 Tightening torque for electrical and mechanical connections 5.7 Protection against overvoltages 5.8 Temperature monitoring systems 6.2 Tappings for voltage setting on HV windings 6.4 Measurement of windings earth resistance 7 Reception, installation and...

1. Safety guidelines A cast resin transformer is an electrical equipment. It must be installed, protected and used in compliance with the existing national and international Standards and Regulations. The possible improper installation and use of a cast resin transformer may cause risks of electric shock or fire. Please, read this installation manual carefully before: lifting, moving or energising the transformer. Every operation on the transformer must be performed when the transformer is not energised. Do not get close to the cast resin transformer before having connected the windings to earth....

1312 1110 Installation, use and maintenance manual 1. Low Voltage Terminal (LV) 5. High Voltage (HV) winding 6. Horizontal movement hooking points 8. Trolley with bidirectional wheels 11. High Voltage Terminals 13. Auxiliary circuit box for probes

IEC 60076-11 - Power transformers - Part. 11: Dry-type transformer. IEC 60076-1 - Power transformers - Part 1: General. IEC 60076-2 - Power transformers - Part. 2: Temperature rise. IEC 60076-3 - Power transformers - Part 3: Insulation levels, dielectric tests and external clearances in air. IEC 60076-5 - Power transformers - Part. 5: Ability to withstand short circuit. IEC 60076-10 - Power transformers - Part. 10: Determination of sound levels. IEC 60085 - Electrical insulation - Thermal evalution and designation. IEC 60270 - High-voltage test techniques - Partial discharge measurements. IEC...

4. Transport, receipt and storage During transport, the transformers must be adequately fixed as indicated in the following images. HV and LV connections must not be stressed by the retaining straps. Once the transformer is at its destination, it is highly recommended to carefully examine it. In particular the following details have to be verified: HV and LV terminals and connections, presence of scratches and/ or cracks on the HV windings and their centering with LV windings, integrity of the protection enclosure (if present), presence of impurities, dirt, foreign body, moisture or water. It...

4.1 Lifting the transformer Use all 4 eye bolts during lifting. Do not allow that the angle between the ropes to exceed 60°. The attachment point must be at least equal to the distance between the eyebolts. Gradually increase the tension on the lifting cables to avoid sudden shock or stress to the transformer. If the transformer has a protective enclosure, remove the central panel of the roof to allow the eyebolts to be attached. Do not stand under suspended loads. Move the transformer only in vertical position.

Lift the transformer avoiding improper lifting (that may cause it to tip over): be careful about the high centre of gravity of the transformer. It is forbidden to lift the transformer by inserting the forks of the forklift under the upper yoke of the core. Installation, use and maintenance manual Cast Resin Transformers

The transformer (with or without enclosure) must be moved using the track or lower jokes where the proper holes are located. Do not move the transformers by applying force on the windings or on their connections. Avoid moving the transformer on sloping surfaces. It is recommended to avoid moving the transformer on the wheels more than 10 m. Movement can be made only in two directions, according to the wheels orientation. Attachment points for horizontal movement using ropes. Installation, use and maintenance manual Cast Resin Transformers

4.3 Storing the transformer If the transformer is not installed immediately, it has to be protected against water, dust, humidity and sunlight even if provided with enclosure. In case of storage the packaging supplied with the transformer must not be removed. If the transformer has been lifted using eyebolts, restore the integrity of the packaging with adhesive tape. The temperature during storage and installation must not decrease below -25°C (unless otherwise agreed at order stage). After a long storage at very low temperatures or in an environment with high humidity, the transformer must be...

5. Installation During the activities of connection and installation, always protect the windings to avoid external parts such as bolts, washers, cable parts, etc. falling into the windings and jeopardizing the insulation capability of the transformer. Dry type cast resin transformers are designed for indoor installations, in a site protected from direct sunlight, in clean and dry environments, without risk of water intrusion. Standard installation must be: 1. At a sea level height not above 1000 m 2. At a temperature of the cooling air not exceeding the following values: a. 20 ° C yearly average...

Between HV and LV connections and transformer windings and delta connections, the minimum distances shown in the table must be respected. HV and LV cables must always be supported to avoid mechanical stress on the terminals.

Cast Resin Transformers 5.1.3 c A High and Low Voltage connection cables must not be laid inside the delta and/or star connection and must not touch it. The connection cables must not touch the windings, or any other active parts of the transformer. Installation, use and maintenance manual

5.2 Connections on the Low Voltage side - LV LV terminals are positioned on the upper part of the transformer and they are made with aluminium bars without galvanic treatment as standard. We recommend to make the cable connection with tinned-copper cable terminals, connecting one or two cables in each hole. Before making the connection, thoroughly clean the contact surfaces with a special cleaner for electrical connections, making sure to dry them completely. In the case of connections with busbar it is necessary to use flexible connections to mechanically isolate the transformer from busbars....