Manual electric arc welding using coated electrodes is performed using the Resanta SAI-250 inverter welding machine.
Operating principle
Inverter welding machine "Resanta 250" works on the process of converting to direct current alternating current at a frequency of 50 Hz. The voltage during this conversion jumps to 400 V. The wide-pulse modulation of the high-frequency voltage allows you to change the welding current strength.
Welder Design
The body of the welding inverter apparatus "Resanta SAI-250" is made of high quality metal. On the front panel of the inverter are power connectors. Welding wires, indicators that control the network parameters and equipment overheating, and the lever for selecting the welding current value are connected to the mentioned connectors.
Functionality "Resanta 250"
Hot air generated during operation of the inverter is discharged through special openings in the housing of the Resanta 250 welding machine thanks to the forced ventilation system. Protection of equipment from excessive overheating during operation is provided by this system.
The automatic shutdown system of the Resanta 250 Prof welding machine turns off the inverter when the power wires are shorted together. The indicator located on the front panel signals the device being turned off. Efficiency and ease of use of the Resanta 250 welding machine are provided by additional anti-stick and hot start functions.
The hot start function implies the instantaneous ignition of the electric arc due to the automatic increase in the current strength at the time of starting the inverter. The second function of the Resanta SAI-250 Prof welding machine - anti-sticking - avoids sticking of the electrode to the metals being processed by reducing the welding current in a critical situation. The current strength rises to the required after sticking is eliminated.
Features of the Resanta inverter
In conditions of significant changes and surges in the power supply network, the Resanta 250 PN welding machine maintains uninterrupted operation. Welding with this inverter model can be performed at low voltage thresholds.
The Resanta device can work with electrodes whose diameter does not exceed 6 mm. The maximum current strength of the inverter is 250 A. For a long time, the Resanta 250 welding machine is able to withstand extreme loads thanks to pre-installed protection systems. This feature of the equipment can be considered its advantage, since the analogues offered on the modern market of welding machines do not have similar characteristics.
In idle mode, the voltage is 80 V. The inverter is equipped with transistors of the IGBT series, which guarantee uninterrupted operation at maximum loads and provide the IP21 protection level of the Resanta 250 welding machine.
The compact dimensions of the inverter and mobility facilitate its use. A handle is located on the device body, which allows transporting the welding machine across the territory of the working site. In reviews of the Resanta 250 welding machine, it is noted that the distinguishing feature of the device is the accuracy and ease of setting parameters. The set parameter values remain unchanged even during power surges.
Inverter Technical Parameters
Characteristics of the Resanta 250 welding machine:
- The inverter load duration at a maximum current of 250 A is 70%.
- The maximum current consumption is 35 A.
- The temperature range of operation of the inverter varies from -10 to +400 degrees.
- The minimum welding current is 10 A, the maximum is 250 A.
- The welding arc created by the inverter has a voltage of 30 V.
A gas generator with a power of 5 kW or more can power the welding machine. The electrodes for working with this model of the welding machine are selected taking into account the fact that when the input voltage decreases, the value of the welding current decreases.
Preparing the inverter for operation
In order to avoid emergency situations, when preparing the Resanta 250 welding machine for operation, it is necessary to observe the safety precautions and the attached instructions. The wires - with the electrode holder and negative grounding - are connected to the inverter in the first place. Before turning on the Resanta SAI-250 welding machine, the minimum current value is set, after which it is connected to the mains or to a gasoline or diesel generator with a capacity of 5 kW or more.
Depending on the electrode used, the required amperage is set. The relevant parameters are indicated in the special table given in the operating instructions for the welding machine.
The inverter regulator is set to the minimum current value after completion of all welding operations, after which the power to the device is turned off. All cables are disconnected from the "Resants" only after its de-energization.
Safety precautions
Before starting operation, the Resanta inverter is desirable to withstand for several hours at a positive temperature. Such measures can avoid the formation of condensate in the apparatus, which can lead to emergency situations. The insulating layer of the welding cables and wires that come with the welding equipment must not be damaged, which can cause damage to the device.
It is prohibited to carry out welding work in rooms where parts are processed with the formation of fine chips or metal dust. Any inclusions contained in the air can settle on the internal elements of the inverter. It is also not recommended to operate the welding machine in rooms with a high moisture content in the air or in the open air during precipitation.
Work with the welding machine is performed only subject to the following rules:
- The place of welding should be well ventilated.
- Fire safety requirements must be strictly observed.
- During work, it is necessary to use protective clothing and a special mask that protects against burns and loss of vision.
The storage of the inverter also has certain requirements:
- The absence of alkali and acid vapors, excessive dust, and fine debris in the room.
- The temperature range is from -10 to +50 degrees Celsius.
Self-repair of the welding machine
Foreign and domestic experts note the high operational resource of the Resant SAI-250 inverter. Subject to all operating rules and storage requirements for the inverter and its transportation, the device can be used for several years, but it may need repair.
Both preventive and unscheduled repair work of welding machines should be carried out only by qualified specialists in the manufacturer's service centers. You can contact the authorized workshops involved in the maintenance of equipment of the Resanta brand. However, the user can perform simple diagnostic and repair work on their own. The need for them arises most often during overheating of the welding machine, as indicated by the indicator on the front panel. This problem is eliminated by disassembling the inverter housing and cleaning its insides of dust and dirt accumulated during operation.
The low efficiency of the Resanta welding device can be caused by a decrease in the power supply voltage or the use of wet electrodes. In the second case, it is enough to dry the electrodes or replace them with new ones before starting welding work.
Advantages of Welding Equipment
The Resanta SAI-250 welding machine is one of the most powerful inverters on the market for similar equipment. Despite the fact that this model is positioned as industrial, it can work from a standard 220 V network. The cost of the inverter at the same time is no different from similar household welding devices.
The advantages of the Resanta apparatus include:
- Operation of the inverter is possible at a voltage level from 140 to 242 V. When the voltage drops by 30% and with unstable readings, the device continues to operate without interruption.
- With this equipment it is possible to use electrodes whose diameter does not exceed 6 mm.
- Welding work can be carried out with any kind of metal;
- The forced ventilation system protects the inverter from overheating and extends its life at peak loads.
- At an open circuit voltage of 80 V, the electrode is quickly ignited.
- The afterburner function of the arc.
- The formation of a high-quality weld.
- Anti-stick function of the electrode during operation.
The advantages of "Resants 250" include compact dimensions and low weight of 5 kilograms, so that the device can be transported on the job site.
Disadvantages of the welding machine
The development of welding equipment manufactured under the Resanta brand is handled by Latvian engineers, but the assembly of devices is carried out in China. For this reason, build quality is poor. It is extremely rare to encounter malfunctions of the electronic part, however, all of them are easily fixed. Separately, it is worth noting the fact that the cost of similar equipment of European production will be several times higher.
The Resanta SAI-250 inverter belongs to the industrial category, however, the maximum time of its operation at the limit value of the current strength is 4 minutes, after which a break is required. At the same time, the device is able to work for a long time at a load of 70%.