Single-phase transformers up to 400 kVA from Breimer-Roth

SINGLE-PHASE TRANSFORMERS

We produce single-phase transformers as isolating transformers or autotransformers with a power rating of up to 400 kVA. The input and output voltage can be up to 1,000 volts (1 kV).

The input voltage and output voltage can be produced on request with or without tapping or additional separate windings. The standard frequency is 50/60 Hz, other frequencies are possible. As an option, we also offer suitable housings as powder-coated sheet steel housings in RAL colors in protection class IP 23 – IP 65. In addition to DIN EN 61558, we also produce transformers with UL/CSA approval.

Standards for our single-phase transformers

The following relevant standards are used in the manufacture and testing of single-phase transformers:
Single-phase control transformers EN 61558-2-2, single-phase isolating transformers EN 61558-2-4, single-phase safety transformers EN 61558-2-6, single-phase autotransformers EN 61558-2-13 and in UL 5085 Low Voltage Transformers (full approval XPTQ2/8) and UL 1446 Electrical Insulation System (OBJY2). DIN VDE 0570 has been replaced by DIN EN 61558.

Protection classes of our single-phase transformers

We produce our products with the following protection classes in accordance with DIN EN 61140/VDE0140-1:

Protection class I (protection by protective conductor):

All electrically conductive housing parts are connected to the protective conductor system of the fixed electrical installation, which is at earth potential. In the case of movable appliances of protection class I, they must have an earthing contact plug (Schuko plug).

Protection class II (protection through protective insulation):

Devices of protection class II have reinforced or double insulation between the mains circuit and the output circuit (or metal housing) and do not have a protective conductor connection. These appliances must not have an earthing contact plug.

Protection class III (protection by safety extra-low voltage):

With these devices, the voltage at the output is max. 50 V AC or 120 V DC (safety extra-low voltage SELV, PELV, FELV). For mains operation, reinforced or double insulation is also required between the circuits (mains). There is no protective conductor connection.

Classification of transformers according to short-circuit strength

Short-circuit proof means that the temperature does not exceed the specified limit values for short-circuited or overloaded transformers and that they remain operational after the overload has been removed.

A conditionally short-circuit-proof transformer is equipped with a protective device that opens the input or output circuit or reduces the current in the event of an overload or short circuit. The transformer is operational again after resetting or replacing the protective device.

A transformer that does not have its own protective device is not short-circuit proof. This protective device must be provided externally to protect the transformer from excessive temperatures.

The fluctuation tolerances in the primary fed-in voltage and the associated fluctuations in the rated power are taken into account in all our series in accordance with the relevant standard.

Single-phase transformer geometry and iron cores used

The core of the single-phase transformers consists of a DIN EI section (BS and BE and BEV series) up to a power of 3 kVA, which is made of grain-oriented or non-grain-oriented transformer core laminations and a coil with at least one primary winding and one secondary winding, depending on the required power loss. For higher power ratings, we use UI laminations with two coils connected either in parallel or in series (BUH, BUF, BDUS, BSUL series) or our optimized strip sections up to a power rating of 400,000 VA (BUVA series).

A special design is the single-phase transformer as a toroidal transformer, which we also produce for you up to a power rating of 3 kVA and freely selectable primary voltage and secondary voltage and the respective current. Here, the toroidal core can be adapted more flexibly to the installation situation in terms of height and diameter.

Transforming to AC voltage and DC voltage

In addition to the AC voltage, it is also possible to transform an AC voltage on the secondary side for a subsequent DC voltage with a defined voltage and current. In principle, the structure of these power supply units is the same as that of single-phase transformers with a core and coil(s), each with at least one primary winding and one secondary winding, plus a rectifier and heat sink. On request, they can also be supplied without capacitors and with a certain residual ripple.

Thanks to different manufacturing techniques in our company, we are able to optimize the magnetic flux in the iron core and thus significantly reduce the power losses in idle and continuous operation.

The following series are available:

BS – Control transformers with fixed voltage combination: Primary side 230 V or 400 V with +/- 5% and an output voltage with 24 V or 230 V power up to 3,000 VA.
BE – Power rating up to 3,000 VA, primary voltage and secondary voltage freely selectable.
BSE – Control transformers with two input voltages (230 V and 400 V) and optionally with an output voltage of 24 V or 230 V
BSV and BEV are the loss-optimized variants of BE and BS.
BSUS/BSUL – control transformers in vertical or horizontal design with fixed voltage ratio and ratings up to 20 kVA.
BUF – single-phase transformers up to 25 kVA with insulation class F, BUH – up to 315 kVA in insulation class H, voltage combinations freely selectable
BUVA – loss-optimized series up to 400 kVA, voltages are freely selectable.

Other special designs such as construction site isolating transformers or transformers for operating theater lights and for rooms used for medical purposes are listed here.