Industries

Power distribution for industrial facilities

Transformers, switchgear and substations for plants and process sites, including urgent replacement of failed equipment and capacity for expansions.

Industrial supplies are shaped by their loads. Large motors draw several times their rated current while they start, and the resulting voltage dip is what the rest of the plant notices. Variable speed drives change that picture and add harmonic currents of their own. Both matter more to the transformer specification than the average running load.

Many industrial enquiries are replacements rather than new builds. When a transformer or breaker fails, the useful questions are what the replacement has to match, which is answered by the nameplate and the existing drawings, and what the owner will accept to shorten the wait: a new unit to the same rating and footprint, or, only where the owner agrees and the condition is documented, a surplus or refurbished one. Whether such a unit exists is established per request, not assumed.

The equipment chain

A typical plant supply. The largest motor's start often decides the transformer rather than the running load.GRIDMVSWITCHGEARTRANSFORMERLVBOARDPROCESSLOAD
A typical plant supply. The largest motor's start often decides the transformer rather than the running load.

What decides the ratings

Motor starting and harmonic loads decide the transformer more often than the steady load does. Where a large motor starts direct on line against a small transformer, the rating is decided by the voltage dip rather than by the running current, and soft starters or drives change the calculation.

For a replacement, the existing installation decides: the voltage pair, the vector group, the impedance if units run in parallel, the footprint and the cable connections all have to match or be deliberately changed.

What to settle early

ConsiderationWhy it matters here
Motor startingSets the rating and the impedance more often than the running load
Drives and harmonicsAffect transformer losses, heating and specification
Parallel operationRequires matching vector group, ratio and impedance
Replacement urgencySurplus or refurbished units may shorten the outage, where acceptable
EnvironmentDust, heat and corrosive atmospheres affect enclosure and cooling
Plant expansionsA compact substation can add capacity without new building work

Equipment for this application

What we need to quote

01For a replacement: nameplate details and photographs of the failed unit
02Rating, voltage pair and vector group
03Largest motor rating and starting method
04Drive and other converter loads
05Whether surplus or refurbished units are acceptable
06How urgently the equipment is needed on site

Related

Send us the requirement

Send the rating, the voltage and the destination, or submit the specification, drawing or nameplate. Anything missing is raised before it reaches a supplier.