Distribution transformers and substations — foundation, erection, HT and LT termination, protection, earthing, oil filtration, testing and charging.
The whole substation on one line — AB switch, lightning arrestor, drop-out fuse, transformer, LT bus and feeders. Note the earthing: two separate body earths and a separate neutral earth, in their own pits. That is what gets checked first.
The transformer is the point where utility HT becomes usable LT, and the whole plant sits behind it. Getting it in is a coordination job as much as an electrical one: civil foundation and plinth, safe unloading and placement, HT side termination and protection, LT side cabling, earthing, and then the tests that have to pass before anyone will let it be charged.
We take the substation as a package — transformer, HT panel or AB switch and lightning arrestors on the incoming side, LT panel and cabling on the outgoing side, body and neutral earthing, fencing and safety signage — so there is one team answerable for whether it charges on the day it is scheduled to.
A distribution transformer needs two separate body earths and a separate neutral earth, at a measured resistance. It is the most common reason a substation is held back at inspection, and the easiest to get right if it is dug and tested rather than assumed.
Transformer oil is insulation, not lubricant. Oil that has picked up moisture in transit or storage has a low breakdown voltage and will flash over on charging. Filtration and a BDV test before energising is a half-day that protects the largest single item on the site.
A lightning arrestor with a poor earth connection, or an HT fuse rated by guess, is decoration. Protection sized against the transformer rating and connected to a tested earth is what actually stops a surge or a fault from reaching the windings.
Plinth level and load capacity checked, transformer unloaded and placed with correct clearances and access for maintenance.
AB switch / G.O.D, lightning arrestors and HT terminations on the incoming side; LT panel, bus and cable termination on the outgoing side.
Double body earthing and separate neutral earthing dug, bonded and measured. Oil filtered, topped up and BDV tested.
Ratio, vector group, IR, winding and earth resistance recorded; transformer charged, checked on no-load then on load, and handed over with the report.
Send the load, the voltage level and the location. We survey, then quote against a defined scope.
