400 kVA Servo Voltage Stabilizer
Our 400 kVA Servo Voltage Stabilizer provides reliable power conditioning for large industrial facilities and power distribution networks. Advanced technology ensures continuous stability.
Ref. SVS-400-3PH · Lead time 3–4 weeks · Made to order from Hapur
See full engineering specification & variants
Key Features
Recommended For
Specifications
| Specification | Value |
|---|---|
| Capacity | 400 kVA |
| Input Voltage | 300V–470V, 3-Phase |
| Output Voltage | 415V ±1% |
| Frequency | 50/60 Hz |
| Response Time | < 20 ms |
| Cooling Method | both air and oil cooled |
| Weight | 1575 kg |
| Warranty | 3 years |
Reading the specification
What these numbers mean for your installation
A datasheet tells you what the unit does. This is what each figure changes about how you specify, feed and site it — worked out for the 400 kVA specifically, not the range in general.
556 A per phase
At 415 V three-phase, 400 kVA works out at roughly 556 A per phase. At 556 A you are normally into parallel cable runs per phase rather than a single conductor. Confirm the terminal chamber accepts the number of runs your cable schedule calls for — discovering it does not, on the day of commissioning, is the most common reason installations at this rating slip.
300V–470V
The unit holds output at 415V ±1% anywhere between 300 V and 470 V in. Pulling a 300 V supply back up to 415 V means adding 115 V — a 38% lift on the incoming supply, with the series winding carrying roughly 111 kVA of the 400 kVA throughput. Below 300 V it runs out of range, and the answer is a wider-window build, not more kVA.
< 20 ms
At this rating the stabilizer is feeding a whole section of the floor, so < 20 ms determines whether one machine's inrush propagates into every other machine on the same board. That is the mechanism behind most "random" tripping complaints we are called out to.
150% for 30 minutes
Direct-on-line starting draws six to eight times full-load current for a few seconds, and 150% for 30 minutes is the margin that absorbs it. At 400 kVA the practical constraint is usually the largest single motor rather than the total: size against that starting current, not against the sum of the nameplates.
Sizing Guide
When is 400 kVA the right choice?
400 kVA is a common HT/LT boundary size — many 400 kVA distribution transformers feed directly into a single factory or campus, and placing a servo stabilizer at this rating on the LT side of the transformer protects the entire downstream installation from grid voltage swings. Brick kilns and ceramic tile manufacturers with tunnel kiln blowers, conveyor motors, and multiple presses specify this rating. It is also the standard size for large hotel properties — banquet hall lighting rigs, commercial kitchen equipment, HVAC, elevators, and guest floor loads together commonly total 350–400 kVA and are extremely sensitive to voltage variations that affect chiller compressor efficiency.
Before you order
Where 400 kVA goes in, and what the site needs
Typical installations
We supply 400 kVA most often into large manufacturing plants, steel mills, chemical processing plants and automotive facilities, alongside textile mills and power distribution substations. What separates those sites is duty cycle rather than load. A rating that runs cool on single-shift work sits near the top of its thermal range on a continuous three-shift line, and that is the point at which oil cooling stops being optional.
Site preparation
At 1,575 kg you are into hydra or gantry territory for the final lift, onto a plinth cast for the purpose. The unloading point matters as much as the destination: plan where the truck stands and how the 1,575 kg travels the last few metres, because that gap is where most delivery-day problems happen. Leave working clearance on the terminal side for cable entry and inspection. Sustained ambient above 45 °C, or an enclosed room without cross-ventilation, requires derating — send us the room conditions and we will confirm the rating still holds where you intend to put it.
Adjacent ratings
If 400 kVA is not the right size
Sizing rarely lands exactly on a catalogue rating first time. These are the ratings either side of it in the same range — compare the specification before you commit.
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View specificationEngineering detail on this configuration
The servo voltage stabilizer pages carry the full design rationale, comparison tables and application notes behind this SKU.
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Send us your kVA requirement, supply voltage range, and site conditions. Our engineer will confirm whether this configuration is correct for your installation, or specify an alternative if needed. No distributors — direct from our factory in Hapur.
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