Posts · Delhi NCR
Keeping transformer hum out of NCR apartments and offices: a low-noise guide
Published by Jaybee Industries
In a tall building, the substation is often only a slab away from homes or offices. Noise has to be designed out.
In Delhi NCR's high-rise residential and mixed-use developments, the electrical substation often sits in a basement, at podium level or in a building next to the towers. Residents and office users are close by. A transformer that hums quietly in an industrial yard can be a real nuisance when the sound travels through the structure into a bedroom or a meeting room. Noise complaints after handover are difficult and expensive to fix, so it pays to plan for them early.
Why transformers hum
The main source of transformer noise is the core. When the core is magnetised by alternating current, its steel changes dimension very slightly, twice in every cycle. This produces a hum at low frequencies and their harmonics. Cooling fans, where fitted, add their own noise. Load current adds some noise from the windings. Low-frequency hum travels well through concrete and steel, which is why it can be heard several floors away.
Specify the noise level
If noise matters, put it in the specification. Ask the manufacturer to state the sound level of the offered design and how it will be measured. Lower noise is usually achieved through core design choices, such as working the core at lower flux density, and through careful construction. These choices can affect cost and size, so it is better to agree them at the enquiry stage than to ask for changes later.
Choose the right type and location
- Dry-type transformers are common in NCR buildings because they can be placed indoors without oil. Their enclosures can be designed with noise in mind.
- Oil-filled units or compact substations placed in a separate substation building or outdoor yard move the noise source away from occupied spaces.
- Avoid placing the substation directly below or next to bedrooms, conference rooms or studios. Put stores, parking or service rooms between them.
Stop vibration from entering the structure
Much of the noise people hear is structure-borne. Measures that help include:
- Anti-vibration pads or mounts under the transformer, selected for its weight.
- Flexible connections for busducts and cables, so vibration does not travel along them.
- A separate or isolated plinth where possible.
- Avoiding rigid contact between the enclosure and walls.
Treat the room
Hard concrete rooms reflect and amplify sound. Acoustic treatment of walls and ceilings, acoustic doors and silenced ventilation openings reduce noise leaving the room. Ventilation must still be sufficient to remove the transformer's heat, so the acoustic consultant and the electrical designer need to work together.
Watch the voltage and harmonics
Running a transformer at a higher voltage than designed increases core flux and noise. Set the correct tap position for the actual supply voltage. Harmonics from drives, UPS and lighting can also increase noise and heating, so share load details with the manufacturer.
Check before and after handover
Measure the noise level at commissioning, at the transformer and in the nearest occupied spaces, and record the results. If complaints arise later, these readings show whether anything has changed, such as loose mountings or fixings.
Discuss your building with Jaybee
Jaybee Industries has manufactured transformers since 1981 at plants in Bathinda, Nalagarh and Ambala, and supplies dry-type, oil-filled and compact substation solutions for NCR projects. Share your building layout, substation location and noise requirements, and the team can discuss design options to match.
Send your enquiry
Call toll-free 1800 309 9948, message us on WhatsApp at +91 98162 95407, or email info@jaybeeindustries.com. Mention this article and your site location so the right team responds. We reply with technical options; we do not publish prices, and every offer is prepared for your specification.
Related pages on this site
- Dry-type transformers
- Compact substations
- Distribution transformers
- NCR project types
- Delhi NCR enquiry
Request a quote Call 1800 309 9948 WhatsApp +91 98162 95407 info@jaybeeindustries.com