Three-phase inverter voltage stabilizers Volter Prostor 21–42 kW (3×7 … 3×14)

Three-phase inverter voltage stabilizers Volter Prostor 21–42 kW (3×7 … 3×14)

Country: Ukraine · Model: Prostor-21 – Prostor-42

Prostor is a set of three-phase inverter stabilizers rated 21, 27, 33 and 42 kW in low, wide housings that go on a wall or into a niche where there is no room for tall units. Accuracy is ±0.5 % and response time about 1 ms. They are used in workshops, small production sites, shops and sites with an unstable supply.

Models and power: Prostor-21 (3×7) — 32 A; Prostor-27 (3×9) — 40 A; Prostor-33 (3×11) — 50 A; Prostor-42 (3×14) — 63 A
Input range: 130–330 V per phase
Regulation accuracy: ±0.5 %
Module per phase (H×W×D): 290×785×215 mm

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Technical specifications

Models and power	Prostor-21 (3×7) — 32 A; Prostor-27 (3×9) — 40 A; Prostor-33 (3×11) — 50 A; Prostor-42 (3×14) — 63 A
Input range	130–330 V per phase
Regulation accuracy	±0.5 %
Module per phase (H×W×D)	290×785×215 mm
Module weight	20.1 kg
Cooling	forced
Type	inverter-based (stepless regulation)
Efficiency	98 %
Response time	1 ms
Output voltage	220 V per phase
Cut-off in transit mode	260 ± 5 V
Start-up delay	4.5–7.5 s
Noise level	34–40 dB depending on load
Ingress protection	IP20
Operating conditions	+1…+40 °C indoors, humidity 40–80 %
Extended input	60–380 V, made to order
Frost-resistant treatment	available to order (Smart, EtalonS, etc.)

Analogues in the catalogue

Specifications are taken from the manufacturer’s technical documentation. Updated 11/08/2026.

Description

Each phase has its own module of 290×785×215 mm weighing 20.1 kg, with forced cooling. Prostor-21 (3×7) at 32 A, Prostor-27 (3×9) at 40 A, Prostor-33 (3×11) at 50 A and Prostor-42 (3×14) at 63 A share the same module dimensions. The input range is 130–330 V per phase and can be extended to 60–380 V to order. The output is 220 V per phase and efficiency 98 %. Protection covers overload, short circuit and overvoltage. The transit cut-off occurs at 260 ± 5 V and the start-up delay is 4.5–7.5 s.

How to choose

Prostor is chosen when the mounting height is limited, since the module is 290 mm high and 785 mm wide. By current the choice comes down to four models, from 32 A to 63 A per phase. For the same 21–42 kW in taller housings there are Parus with a 630×430×140 mm module and EtalonS with a 640×320×122 mm module, while Smart covers 81 kW and 105 kW. Supplied as the official representative in Ukraine.

Request a price and lead time

Three-phase inverter voltage stabilizers Volter Prostor 21–42 kW (3×7 … 3×14), Volter. We reply within one business day.

Or email office@usk.ua or call +38 (044) 339-50-20.

FAQ

Where can Prostor be installed?

The low, wide 290×785×215 mm housing is meant for a wall or a niche where there is no room for tall units. Ingress protection IP20 means installation in a closed room.

What is the noise level of Prostor?

Noise is 34–40 dB depending on load. Cooling is forced.

What temperature and humidity are allowed for Prostor?

It is rated for +1…+40 °C in a closed room at 40–80 % humidity.

Can the input range of Prostor be extended?

Yes, a 60–380 V version is available to order, while the standard range is 130–330 V per phase. Frost-resistant treatment is also available to order.