Does a 315 kva distribution transformer work for a 500KVA load?

The Transformer that we are using for supplying the load has to supply both Active power as well as Reactive power demand by the load. If we are using a 315KVA transformer for supplying a 500KVA load then there is a chance that the transformer may get damaged due to overload.

 

Another case is that, 500KVA is the total power consumption by the load at Rated condition so if we are operating the load at a lower power
consumption condition such that the total power consumption is 315KVA or below that then there may be a chance that we can operate a 500KVA load by a 315KVA transformer.

 

It may work. But depends on some factors. There is a thing called overloading factor which indicates the ratio of allowable overload to rated load.

There will be more generated heat as you over load the transformer with 500kVA load. If sufficient cooling is provided then it can be loaded beyond its rated value.

Overloading is done mainly in power transformers with additional cooling arrangements like OFAF (oil forced air forced) [oil is pumped to increase the rate of flow of oil in transformer oil serves as a coolant and air flow is increased via multiple fans connected with fin to increase heat dissipation rate]

 

What is the specification of 315 kVA transformer?

 

Nominal system voltages for 315 KVA transformers are 11KV, with a standard voltage ratio of 11000/400V. Different countries have slightly different voltage levels. In addition, it has specifications of load losses of 2800W and no-load losses of 324W.

 

315 kva Transformer nameplate

315kVA-10/0.4kV Transformer Name Plate

Type	Resin cast dry type transformer
Standard	IEC60076
Rated Power	315 kVA
Frequency	50 HZ
Phase	Three
Cooling Type	AN
Primary Voltage	10 kV
Secondary Voltage	0.4 kV
Winding Material	Aluminum
Vector Group	Dyn11
Impedance	6%
Tap Changer	NLTC
Tapping Range	±2*2.5%
No Load Loss	750W
On Load Loss	5500 W
Accessories	Wheels, Supporting Insulator on primary side, Plug type HV terminal, Lifting eyes, Earthing bolts, Temperature controller, PT100 probe, CT
Remarks	N/A

 

The epoxy resin dry type transformer has the characteristics of good electrical performance, strong lightning impact resistance, strong short-circuit resistance, small size, and light weight. The temperature display controller can be installed to display and control the operating temperature of the transformer windings to ensure the normal service life of the transformer.

 

The function of temperature controller:

According to the temperature rise, the cooling fan is automatically controlled to stop, overtemperature alarm and ultra-high temperature tripping to ensure the safe operation of dry power transformer.