Online UPS and servo stabilizers for sugar mills
The crushing season runs roughly October to April and does not pause. A control-supply trip does not just stop the mill — it strands cane in the carrier and costs hours to restart.
What actually goes wrong
A sugar factory is the hardest electrical environment we work in. Enormous direct-on-line motor loads on the cane carrier, mills and centrifugals drag the bus voltage down every time they start. The co-gen set and the grid hand back and forth. VFDs across the plant pump harmonics into the same board that feeds the DCS. And most mills sit on rural feeders where the incoming supply was never good to begin with. The instrumentation that has to keep working through all of it is the most sensitive equipment on site.
What to get right
The decisions on this list are the ones that are expensive to change after the equipment is on site.
Season, not year, is the unit of planning
Everything gets serviced in the off-season, because nothing can be taken out of circuit during crushing. Schedule the AMC visit for May, not January.
DCS, PLC and instrumentation
Control room, field instruments and the weighbridge belong on a UPS. The drives do not. Protecting the control layer costs a fraction of protecting the plant and prevents the same downtime.
Motor starting sag
Size the stabilizer against inrush from the largest DOL motor, not against running load. A mill that measures 300 kVA running can pull far more for a second or two.
Boiler and turbine DC systems
Emergency lube oil pumps, trip circuits and protection relays run off a DC bank. That bank needs a proper float-cum-boost charger and an annual load test, not a voltage check.
Co-gen changeover
Export, import and island modes each behave differently. The ATS and its interlocking have to be coordinated with the co-gen protection, not bolted on afterwards.
Bagasse dust and humidity
Standard IP20 cabinets clog. Specify IP54 or better with filters that actually get changed, and put the battery bank somewhere ventilated.
What we supply into this sector
Online UPS
True double-conversion topology from 3 kVA to 200 kVA across three series, with single-phase or three-phase output. Zero transfer time, pure sine output held to ±1%, and up to 96% efficiency. Built and load-tested in Pune.
Servo Voltage Stabilizer
5 kVA to 500 kVA, air or oil cooled, correcting to ±1% output. The right first fix when the MIDC feeder swings all day and the equipment keeps tripping on undervoltage.
Industrial Battery Charger
SMPS chargers from 5 A to 30 A and float-cum-boost chargers from 5 A to 200 A, sized to the bank rather than to a catalogue number.
Isolation Transformer
Galvanic separation between supply and load, with electrostatic shielding that attenuates common-mode noise by 100 dB or better. 1 kVA to 500 kVA.
Automatic Transfer Switch (ATS)
The supply you are on fails, and the load moves to the one that has not — with nobody at the panel. 10 A to 150 A, single phase and three phase.
Through the life of the machine
Questions we get asked
Anything not covered here, call us — most of it is faster to answer on the phone.
01What should be on UPS in a sugar mill?
The control layer: DCS and PLC racks, field instrumentation, the control room workstations and servers, the weighbridge, and boiler and turbine protection. These represent a small fraction of the connected load but nearly all of the downtime risk. Motors and process drives ride on the co-gen and the DG instead.
02When should a sugar factory schedule maintenance?
The off-season, between roughly May and September. Nothing can be isolated during crushing, so preventive work, battery load tests, stabilizer servicing and any replacement all have to land in that window. We plan the year backwards from the season start date.
03Do you supply to sugar mills outside Pune district?
Yes — supply goes across the Maharashtra sugar belt. Service outside our published areas is contracted individually against distance, and we will tell you honestly what response time is realistic before anything is signed rather than after.
04What is different about power in a sugar mill?
Two things: the season and the co-generation. A mill runs hard for a crushing season and stands for the rest of the year, so equipment ages by campaign rather than by calendar and the pre-season check matters more than a routine one. Co-generation means the plant is sometimes its own source and sometimes the grid’s, and the changeovers between them are where instrumentation and control loads are most exposed.
05Why do control systems trip during changeover to co-gen?
Because the changeover is not instant and the control does not tolerate the gap. Synchronising, islanding and returning to grid all involve brief disturbances, and PLCs, drives and instrumentation ride through far less than the plant around them. Putting the control and instrumentation loads behind a UPS means the process keeps its state through a changeover that the mechanical plant handles easily.
06Should equipment be serviced between seasons or during?
Between, and with enough lead time to order parts. A mill that discovers a failed battery bank in week one of crushing has no good options. The off-season is when a discharge test, a thermal scan and a capacitor check can be done without stopping anything, and when a replacement can arrive on a normal lead time rather than an emergency one.
07Do stabilizers help with the voltage swings during crushing?
Where the swing is a magnitude problem, yes — large drive starts and load changes pull the voltage around, and a servo stabilizer holds the downstream supply steady. Where the problem is a momentary interruption or a harmonic issue from the drives themselves, it will not, and the fix is elsewhere. A power quality log across a crushing shift usually separates the two quickly.
We will do the load grading with you
Site survey, load list and a single-line diagram before anything is quoted. That is where the specification is actually decided.