Resistance Welding Transformers
Automation International designs and builds new resistance welding transformers. The transformers range in sizes from: 15 KVA to 1200 KVA single-phase AC-style and three-phase DC design from 250 KVA to 2000 KVA power supplies.
Automation International also provides transformer rebuilds and repairs on all Resistance Welding Transformers. Transformers are completely torn down and inspected for damage before the repair process begins. Upon completion of the repair, the transformers are fully tested to ensure proper operation.
Other services include:
- Emergency, quick turnaround repairs
- Full “new” warranty on work performed
- Engineering staff to determine the best rebuild approach on damaged transformers
- On-site inspection by qualified technicians
- Power data engineering services
Design & Manufacturing
AII-brand, water-cooled welding transformers are designed to deliver power at high efficiency with low impedance. Energy loss is minimized by the use of stacked silicon steel cores. Secondaries are cast of highest quality copper with non-corrosive copper water-cooling tubes brazed or cast to the outer edges of the secondary sections. This eliminates excessive rise in temperature under continuous demanding service. Primary coils are wound of copper ribbon insulated between turns and double wrapped. The coils are dipped in a moisture-, heat-, and oil-resistant varnish and then baked. That process is repeated twice for optimum effect. When finished, the entire transformer assembly is also dipped and baked in the same varnish solution.
- Various voltages and frequencies to meet customer requirements
- Full potting (secondary end positively sealed against contamination)
- Secondary pad configurations based on customer needs
- Thermostat protection devices
AC / DC3 / MFDC
AII-brand transformers can be configured for various application requirements.
Single-phase AC (alternating current) transformers are designed with single-loop secondaries in sizes ranging from 15 KVA to 1200 KVA. Ratings are typically based on 50% duty cycle ratings. Transformers are generally water-cooled devices although some air-cooled units can be provided in the smaller sizes.
Three-phase DC (direct current) transformers can be provided in 3-pack or 6-pack configurations depending on the current and duty-cycle demands.
The DC3 units include three (3) single-phase transformers specially packaged in a stack formation with the primary fed to the unit by a 3-phase primary power supply. The secondary output side of the transformers are coupled to specially designed rectifier arrangements where the low voltage / high current is converted to a direct current sine wave disposing of the frequency altogether and thereby, nullifying the reactance and associated voltage drops almost totally in the welding field.
The DC6 units are very similar in principle to that of the DC3 units, where essentially six (6) transformers are packaged as two parallel DC3 units fed by the same 3-phase primary power supply. The outputs are likewise bolted to rectifiers with the output side of the rectifier pulled to a common secondary output with single point connection.
DC power supplies can be provided in sizes ranging from 250 KVA to 2000 KVA and above. The three-phase rectifiers provide a lower power demands and provide solutions to certain problems caused by alternating welding currents.
The MFDC (medium frequency direct current) power supplies takes advantage of the inverse relationship between the frequency and core size. Increasing the frequency will allow the construction of smaller core. The higher frequency signal feeding the transformers is provided by special inverter controllers. However, operating the welding tool with high frequencies is not practical due to the increase in reactance, therefore the output signal from the transformers must be rectified as with the standard DC power supplies. The higher frequency signals allow for precise control within the weld timing (millisecond-based), which can be very useful in critical applications. The higher frequency power does provide increased efficiencies and some power savings.
MFDC power supplies can be provided with welding currents in excess of 200,000 amperes.