India’s first Solar Online UPS: the Intelli S 40 KVA that runs 22 X-ray machines on sunshine

A diagnostic centre running twenty-two X-ray machines is one of the harshest power problems you can hand an engineer. The loads are sensitive, the surges are vicious, and a flicker at the wrong moment can ruin an exposure or crash a system. The Intelli S 40 KVA was our answer: a solar-fed online UPS built for exactly the loads that cannot tolerate a single break.

1 What an “online UPS” really means

Most backup systems — ordinary inverters and even line-interactive UPS — keep your equipment on the raw mains until the power fails, then switch to battery. There is always a tiny transfer time, and all the noise and surges of the grid pass straight through to your load. An online, double-conversion UPS works completely differently: it continuously converts incoming AC to DC and back to a brand-new, clean AC sine wave, so your equipment always runs on the inverter, never on raw mains. There is zero switchover time, and the grid’s spikes, sags and noise never touch your load. It is also the architecture we became the first company in India to power with solar.

2 Why X-ray and medical loads demand it

An X-ray generator draws a violent, momentary surge the instant it fires — and it needs perfectly clean, stable power to do it safely and repeatably. Multiply that by a busy imaging department and you have a load profile that destroys ordinary backup gear. A single Intelli S 40 KVA can carry an entire diagnostic floor — for example, up to:

3 The Intelli S advancements

The Intelli S sits at the top of the family. It takes everything our Colossal 40 KVA Solar PCU does and lifts it into a different class of protection:

4 Solar, at the heart of it

What makes the Intelli S special is that all of this protection is solar-first. Through the day it leans on free solar energy to carry the load and replenish the 360V battery bank, before it ever draws from the grid. So a hospital or diagnostic centre gets the highest grade of clean, uninterrupted power and a falling electricity bill at the same time — the two things that almost never come together in critical-power equipment.

5 India’s first Solar Online UPS — and the dates prove it

This is the part I am proudest of. We designed and built India’s first Solar Online UPS in 2015 — and the public record proves it. The product film above has been live on the Su-Kam channel since 18 April 2018, years before a solar-fed online UPS was a fashionable idea anywhere. We were first to the concept, and first to put a working machine in front of customers.

A transformer-based online UPS is the gold standard for protection, but it is also a power guzzler: the continuous double conversion and the heavy isolation transformer — the very thing that shields you from India’s dirty, surging grid — mean it draws power around the clock. Chinese makers ran from that problem by going transformerless and triple-conversion: lighter and cheaper, but they threw away the galvanic isolation and the ruggedness Indian conditions demand. I refused to drop the transformer. Instead, we built an MPPT solar charge controller right into the online UPS, so solar feeds the DC bus directly and the grid charger barely runs — keeping the protection, killing the energy waste.

And we proved it in the lab, not just on paper: a 30 KVA unit held full load for over six hours with the main transformer stable at 128°C (a 52°C safety margin) and an AC-to-AC efficiency of 84.28%. You can read the full engineering story — the thermal tests, the waveforms and the efficiency data — in how we built India’s first Solar Online UPS.

Further reading and references: Su-Kam Power Systems (Wikipedia), the pv magazine interview, a 30 KVA / 360V three-phase listing, and the Su-Kam Solar YouTube channel.

6 Where it fits in the range

The Intelli S is the critical-power sibling of our three-phase Solar PCU family. If the Colossal 30 KVA and 40 KVA PCUs run your clinic, workshop or factory, the Intelli S is what you reach for when the load simply cannot tolerate even a flicker — an operating theatre, an imaging department, a data room. It is part of the same story of how we turned the inverter into a solar power plant, scaled all the way up to the 80 KVA three-phase machines an Indian company built first. You can read the technical background on the online double-conversion UPS.

7 A note from me

I have always believed that the hardest loads deserve the best engineering, not the cheapest. A child waiting for an X-ray, a patient on a table in an operating theatre — the power behind them should never be the weak link. We built the Intelli S so that an Indian hospital could have power as clean and unbreakable as anything in the world, and have it run on the sun. That is the kind of product I am proudest of: one where good engineering quietly protects people who never see it.