Industrias Electromecánicas Magnetrón is a Colombian transformer manufacturer with plants in Pereira, Risaralda. It makes conventional and self-protected pole-mounted, pad-mounted, submersible, encapsulated and open-winding dry-type transformers, small power transformers, switching boxes and equipment for solar and for Oil & Gas, such as variable-frequency step-up transformers and 12- and 24-pulse phase-shifting transformers.
What it is and where it is used
Magnetrón (Industrias Electromecánicas Magnetrón S.A.S.) is a Colombian transformer manufacturer with plants in Pereira, Risaralda. Its catalog covers conventional and self-protected pole-mounted transformers, pad-mounted, submersible, dry-type, small power transformers, switching boxes and lines for solar energy and Oil & Gas.
Its transformers are on overhead and underground utility networks in Colombia, in residential complexes, commerce and industry, in solar plants and in oil fields. For context, see distribution transformer.
Variants: pole, pad-mounted, submersible, dry, power and Oil & Gas
| Line | Application | Main difference |
|---|---|---|
| Conventional pole-mounted | Overhead networks | Protections installed separately |
| Self-protected pole-mounted (CSP) | Overhead and rural networks | Built-in protections |
| Pad-mounted | Underground distribution | Dead-front cabinet |
| Submersible | Vaults and floodable chambers | Designed to operate occasionally submerged |
| Encapsulated and open-winding dry-type | Indoors and industry | Oil-free |
| Power (small power) | Industrial substations | Oil-immersed |
| Variable-frequency step-up (SUT) | Oil & Gas | Raises the voltage at the output of a drive |
| 12- and 24-pulse phase shifter (PST) | Oil & Gas | Reduces harmonics at the drive input (harmonics) |
| Switching boxes | Underground networks | Circuit sectionalizing |
The power, voltages, connection group and taps of each unit are read on the nameplate; Magnetrón does not publish an MVA ceiling for its power line on its front page.
Main features
- Design and manufacture in Colombia, which the company highlights as developed by Colombian engineers.
- Complete distribution line for overhead and underground networks.
- Special transformers for drives (SUT and PST) in Oil & Gas, an application where harmonics and variable frequency demand a dedicated design.
- Service and warranty, with a safety manual for field work published by the company.
The choice between pole-mounted, pad-mounted, submersible or dry depends on the type of network, the installation site and what the utility requires in its connection specification; in Oil & Gas, on the drive and the well that the transformer feeds.
Communications and integration
A distribution transformer normally does not communicate. In power transformers, dry-type units and the SUT and PST of Oil & Gas, temperature, level and pressure alarms reach the protection or the control system through contacts. In a well, the drive and its supervision system usually concentrate those signals.
Frequently asked technical questions
- Magnetron 75 kVA transformer: the rating is defined by the load calculation; the price depends on the configuration and we do not publish it.
- Acceptance tests: compare the on-site tests with the factory protocol; see turns ratio test.
- Self-protected unit that trips: check the load, the low voltage and the state of the internal protections before restoring.
- SUT that overheats: at the output of a drive there are harmonics and frequencies other than 60 Hz; the real load and the output filter matter.
- Switching box on an underground network: it lets you sectionalize sections without cutting the whole circuit; its operation follows the utility’s procedure.
- Transformer submerged after a flood: before energizing, check the insulation and the oil; see dielectric oil analysis.
Standards and specifications
- Local code and utility specification. The design, the protections and the product certification of a distribution transformer follow the local code and the requirements of the utility that owns the network, and each utility adds its own specification. If the transformer is installed on a utility network, that specification takes precedence over the manufacturer’s catalog. Confirm which edition applies at the time of purchase.
- IEEE reference. IEEE C57.12.20, in its 2023 edition, covers overhead-type single-phase and three-phase distribution transformers, liquid-immersed and self-cooled, up to 500 kVA, with high-voltage ratings up to 34.5 kV and low-voltage ratings up to 7,970/13,800Y V.
What is inside a self-protected transformer
In the conventional pole-mounted type, sectionalizing and protection are on the pole: fuse cutouts upstream, medium-voltage surge arresters and a breaker or fuses on the low voltage side. The self-protected unit builds those elements into the tank itself. That is why the acceptance test includes verifying that each element works, and the check after an operation includes restoring the protected element, not only the transformer. A self-protected unit that trips repeatedly indicates overload, a fault in the low-voltage network or an internal protection that operated; the order of checking is the load, the low-voltage network and, last, the transformer.
Losses and efficiency
Short-circuit voltage is measured at 85 °C as a reference, and no-load losses (which are paid every hour of the year) and load losses (which depend on the real load) are verified against the tables in the standard or the utility specification. If the transformer serves a load with a lot of time at no load, such as lighting or a residential complex, the no-load losses weigh more in the life-cycle cost than the load losses. For the acceptance protocol, check that the measured values of losses and impedance are within the tolerances of the standard cited in the contract.
SUT and PST in oil and gas applications
The variable-frequency step-up transformer (SUT) connects to the output of a variable frequency drive to raise the voltage toward a well motor or a submersible pump. The 12- or 24-pulse phase shifter (PST) feeds multi-winding drives to cancel harmonics at the input. The harmonic criterion at the point of connection is IEEE 519. In an SUT, the long cable and the variable frequency change the voltage stress on the insulation; the manufacturer defines the insulation level and the output filter, and these data are requested in the design. See variable frequency drive harmonics.
Acceptance on site: points to watch
- Compare the nameplate with the protocol and with the order: rating, voltages, connection group, taps, impedance and oil weight.
- Check for leaks, cover and bushings after transport, and the oil level.
- On submersible units, check the sealing of bushings and cover before installing; after a flood, the insulation and the oil are checked before energizing.
- The ratio and the winding resistance are measured on all taps, not only the nominal one; see winding resistance test.
How we help
At Tiza Group we do not sell transformers. We test and commission Magnetrón transformers and those of any brand: ratio, winding resistance, insulation, oil and protection, and coordination with the upstream protection. We do this in Colombia, or elsewhere on request. See transformer testing within testing and commissioning. Write to us through the contact page.
Related guides
- Distribution transformer
- Variable frequency drive harmonics
- Turns ratio test
- Winding resistance test
- Rymel transformers
- Pad-mounted transformer
- WEG transformers
References
- IEC 60076-1, power transformers: general.
- IEC 60076-11, dry-type transformers.
- IEEE C57.12.20, overhead-type distribution transformers.
- Industrias Electromecánicas Magnetrón, corporate site (product lines, plants and service).
Frequently asked questions
Where does Magnetrón manufacture its transformers?
In Pereira, Colombia. The company reports an assembly plant at kilometer 9 of the Pereira–Cartago road and a metalworking plant at kilometer 2 of the road to La Virginia, in Cerritos.
What is a self-protected Magnetrón pole-mounted transformer?
It is a pole-mounted distribution transformer with built-in protection, which Magnetrón calls completely self-protected (CSP). In the conventional one those protections are installed separately. The exact protections are confirmed in the model data sheet.
What tests are done on a 75 or 150 kVA Magnetrón transformer before energizing?
Inspection, turns ratio, winding resistance, insulation and, if required, dielectric strength and analysis of the oil, plus checking fuses, surge arresters and grounding. The results are compared with the factory protocol.