Description

YBM-24 type pad mounted transformer

General:

YBM()series pad mounted transformer is suitable for 7.2kVup to 36kV ring power supply and terminal power supply system as HV distribution calculation and protection equipment. In the substation except transformer there are 4 load switches, two-position load switch, protection fuse and plug-in fuse in the HV side.

We can install control electrical, distribution electrical, compensation electrical and meters. This substation can use indoor or outdoor.

Service environment：

a) Air temperature: Maximum temperature: +40°C; Minimum temperature:-25°C

b) Humidity: Monthly average humidity 95%; Daily average humidity 90% .

c) Altitude above sea level: Maximum installation altitude: 2500m

d) Ambient air not apparently polluted by corrosive and flammable gas, vapor etc.

e) No frequent violent shake

Structure characteristics:

The box structure of this product is divided into two parts. In front is HV and LV operation room. In the HV room including HV terminals, load switch, off-load switchgear, plug-in fuse, pressure relief valve, thermometer, oil level indicator and oil drain valve. In LV room including LV terminals. In the back sector are oil tank and radiator, and transformer winding and iron, load switch and protection fuse are in the oil tank.

Pad mounted transformer structure is divided into front and rear parts.The front parts is LV and HV cabin including high and low voltage terminals, load switch, no-load tap-changer, plug-in fuse,pressure relief valve, oil temperature gauge, oil level gauge.The rear parts is oil tank including transformer oil,iron core ,winding and current-limiting backup fuse.

A type steel sheet         B type steel sheet          H type steel sheet         S type AL alloy

Protection

The pad mounted transformer is protected from the combination of current-limiting backup protection fuse and Plug - in fuse . The protection principle is advanced,

economical and easy to operate.

Plug-in fuse is the brief element of oil-transformer,to protect the equipment when over-current.When install the fuse wire in it,the plug-in fuse will provide the safe,highly efficient protection,according to the current, oil-temperature.

The Backup Current limiting fuse highly efficient current-limiting section minimizes the effects of high fault current stresses on equipment and the distribution system.Its minimum interrupting rating is coordinated with that of a low current interrupter to avoid undesirable low current operation;yet its maximum interrupting rating will clear the highest fault currents likely to occur. Higher continuous current ratings can be achieved by connecting two fuses in parallel.

Connector

Loadbreak Elbow connector is a fully-shielded and insulated plug-in termination for connecting underground cable to distribution power system of pad mounted transformer, surrounding power supply branch box,cable branch box equipped with loadbreak connections. It can meet the demand of lines in nuclear.

The loadbreak Elbows are molded using high quality sulfur-cured insulating and semi-conducting EPDM rubber.Standard features include a coppertop connector,

tin-plated copper loadbreak probe with an ablative arc-follower tip and stainless steel reinforced pulling-eye.An optional capacitive test point.made of corrosion resistance plastic,is available for use with fault indicators.

Load break switch:

The Load break switch is three phase gang-operated type,with spring mechanism,and it is able to switch on/off under on load condition. And there is 2 different types Load break switch:2-position& 4-position. 2-position is used for radial feeder design distribution system,and 4-position is used for loop feeder design distribution system.

Technical data

Electrical schematic diagram