Skip to main content

THREE-PHASE, PAD-MOUNTED DISTRIBUTION TRANSFORMERS INSTRUCTION MANUAL FOR UNDERGROUNDSERVICE

THREE-PHASE, PAD-MOUNTED DISTRIBUTION TRANSFORMERS INSTRUCTION MANUAL FOR UNDERGROUNDSERVICE
A step-by-step guide in receiving, commissioning, testing, etc., of pad-mounted distribution transformers provided to us by GE.

The equipment covered by these instructions should be operated and serviced only by competent technicians familiar with good safety practices. These instructions are written for such personnel and are not intended as a substitute for adequate training and experience in safe operating procedures for this type of equipment.

Receiving
Immediately upon receipt of the equipment, and before putting it into service, inspect the transformer for any damage that may have occurred during shipment or storage. If rough handling is evident, file a damage claim with the transport company immediately and notify the nearest General Electric Sales Office promptly. Tighten any parts that may have loosened during shipment.

Handling
Lifting lugs are provided for lifting the complete transformer. Jacking space is provided in the base of the transformer to facilitate lifting with jacks. The transformer must never be moved or lifted by placing jacks or tackle on the radiators, the high-voltage and low-voltage compartments, or other attachments. When using a fork lift to move the transformer, lift from the tank rear with the shipping skid in place.

Storage
Transformers should be stored with the tank sealed and filled with oil to the proper level. Compartment doors should be closed to prevent damage to bushings and accessories. The storage area should be a flat, dry surface and the transformer should be protected from mechanical damage.

Inspection
The transformer covered by this instruction is shipped ready for installation and will not require drying unless moisture has been allowed to accidentally enter during transit. It has been filled with oil at the factory to the 25° C liquid level and sealed. Check the level by one of the following methods:
• Read the liquid level gauge.
• Vent the pressure-relief valve and then carefully remove the pipe plug located in the low-voltage compartment for this purpose. Reseal after use.

Load OperationFor continuous loading in standard ambient temperature, the total balanced load on a transformer should not exceed the name plate rating. Prolonged overloading may result in shortened transformer life (see ANSI C57.91). Voltage should be applied only to transformers filled to the correct level with insulating liquid.

External Finish Maintenance
The condition of the transformer finish should be examined at regular intervals. If the finish is weathered, clean it thoroughly and refinish with a good grade of durable paint, as recommended by GE.

Labels:

Comments

Post a Comment

Popular posts from this blog

PARTS OF A POWER TRANSFORMER

What are the name of the basic parts of a Power Transformer? We can not deny the fact that only a handful of electrical engineering students are presently familiar with power transformers especially on what it looks like. Unlike a transformer we found in our homes, a power transformer’s appearance and construction is somewhat more complicated. It is not just a simple winding with a primary and secondary terminal although basically any transformer has one. The function that a power transformer plays in an electrical system is very important that an electric utility can not afford to loss it during its operation. Our discussion here will focus more on the basic parts and functions of a power transformer that are usually tangible whenever you go to a substation . Although not all power transformers are identical, nonetheless they all have the following listed parts in which the way of construction may differ.
48 comments
click here to continue

ELECTRIC MOTOR FRAME SIZE STANDARD SPECIFICATIONS

ELECTRIC MOTOR FRAME SIZE STANDARD SPECIFICATIONS How is electric motor frame size being specified? Motor frame dimensions have been standardized with a uniform frame size numbering system. This system was developed by NEMA and specific frame sizes have been assigned to standard motor ratings based on enclosure, horsepower and speed. The current standardized frames for integral horsepower induction motors ranges from 143T to 445T. These standards cover most motors in the range of one through two hundred horsepower. Typical example of where you can locate the frame is shown in Fig 1.2.D – Frame No. The numbers used to designate frame sizes have specific meanings based on the physical size of the motor. Some digits are related to the motor shaft height and the remaining digit or digits relate to the length of the motor. The rerate, or frame size reduction programs were brought about by advancements in motor technology relating mainly to higher temperature ratings of insulating mate
5 comments
click here to continue

ELECTRIC MOTOR NAMEPLATE SPECIFICATIONS

How do we interpret an electric motor nameplate? Motor standards are established on a country by country basis.Fortunately though, the standards can be grouped into two major categories: NEMA and IEC (and its derivatives). In North America, the National Electric Manufacturers Association (NEMA) sets motor standards, including what should go on the nameplate (NEMA Standard MG 1-10.40 "Nameplate Marking for Medium Single-Phase and Polyphase Induction Motors").
40 comments
click here to continue