Transformer selection for substation
Oil filled transformers must be used for all outdoor substation. Some indoor substations (e.g. most industrial applications) should use oil filled transformers unless contractor or the consumer specifies otherwise.

Dry type transformers should be used for indoor substations located in high rise buildings (commercial and large residential blocks) and other major buildings frequented by the public (e.g. Convention/Exhibition centres and major shopping complexes). Dry type transformers for other high fire risk applications may also be specified.
The transformer should be such as to supply the whole of the load by one transformer. However where the maximum demand exceeds 1000kVA, then provision for two transformers and associated switchgear must be allowed.

Transformer space & ventilation requirements
Substations must provide sufficient space and ventilation to accommodate 1500kVA transformers, ensuring sufficient ventilation is provided for future load, even though smaller units may be initially installed.
Transformers must be separated from walls, ventilation equipment and other obstructions by a minimum of 900 mm. Transformers must not be directly placed under ventilation duct openings. With the exception of fire damper trip wires (if required), no item of equipment, installation or obstruction is to be placed over a designated transformer space.
Natural ventilation is not adequate for indoor substations. Mechanical ventilation must be provided. Section 10 details ventilation requirements.
As a guide, one general arrangement has been provided for each style 3 of indoor substation. Provided all clearance and access requirements are maintained, other arrangements may be used. An Energex Planning Officer must approve any alternate arrangement. Outdoor substations must be arranged in accordance with the standard layouts provided.
Title: | Design and construction manual for commercial and industrial substations by Energex |
Format: | |
Size: | 20.8Â MB |
Pages: | 263 |
Download: | Right here | Video Courses | Membership | Download Updates |

I have a 11/.440 kv, 25 kva, 3phase transformer for my domestic & commercial building, since 3years. But, till date my full load trivector meter has hardly touched 9-10 kw
Now Iam thinking to replace the 25kva trafo to a lower rating DRY TYPE transformer
Can u suggest any technically viable points , about feasibility of changes
Electrical Switchgear
And Industrial drives basics for diploma level study
Dear Sir,
i will visit your website, i need electrical substation for our shopping mall. our capacity : 4000 kva, set up out site of shopping mall. my we chat no. +8801711107560 , please send me substation Details with price offer.
The photo seems odd as there are no fire wall separators. Which country is this?