Servo stabilizers and transfer switches for cold storage
Compressor motors are unforgiving of low voltage, and the stock in the chamber does not care whose fault the outage was.
What actually goes wrong
A refrigeration compressor running at low voltage draws higher current to deliver the same torque, and the motor windings heat. Do that daily for a year and the motor fails in the summer, which is exactly when you cannot afford it. Cold storage sites are also frequently on rural or semi-rural feeders where the voltage profile is at its worst.
Working in cold storage & food processing
What to get right
The decisions on this list are the ones that are expensive to change after the equipment is on site.
Motor starting current
A DOL-started compressor pulls six to eight times full-load current. Size the stabilizer for the inrush, not the running load.
Single phasing protection
The fastest way to destroy a three-phase compressor. Single-phase preventer protection belongs in the panel, not as an afterthought.
Fast changeover
The tighter the transfer window when the supply swaps over, the less the chamber temperature drifts while it happens.
Control and monitoring backup
The compressors can wait for the DG. The temperature loggers, alarms and controls should not — that is a small UPS, not a large one.
Outdoor and washdown
IP55 enclosures where equipment sits outdoors or in a washdown area.
Rural feeder profile
Wider input windows than the standard 340–480 V are often needed. Log the incoming supply before specifying.
What we supply into this sector
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.
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.
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.
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.
Through the life of the machine
Cold Storage & Food Processing — questions we get asked
Anything not covered here, call us — most of it is faster to answer on the phone.
What size servo stabilizer does a cold storage unit need?
Size against compressor starting current, not the running load. A plant with 100 kVA of running load and DOL-started compressors may need 200 kVA or more of stabilizer to hold voltage through the inrush. Tell us the compressor ratings and the starting method — DOL, star-delta or soft starter — and it changes the answer substantially.
Does a cold store need a UPS as well as a DG?
A small one, yes, though not for the compressors. The controls, temperature loggers, alarms and communications should ride through the DG start window so you keep an unbroken temperature record and any alarm during the changeover still reaches someone. That is a few kVA, not a few hundred.
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.