Choose a welding generator by the electrode you use most, not by the biggest number in the catalogue. If you mostly weld with 2.5 to 3.2 mm electrodes (3/32” to 1/8”), a 200 A machine covers a full working day. If you run 4.0 mm all day or need 5 or 6 mm, go to 300 A or more. Then check three figures: the duty cycle, the auxiliary power for tools and the fuel per shift. This guide works through each one with numbers.
What a welding generator is
A welding generator puts three things on one frame: a diesel engine, a welding generator and an AC outlet for tools. Think of a fence line on a farm, a steel structure on a building site or a repair at a mine. On a site like that, with no grid power, it replaces both the workshop welder and the generator.
Step 1: the electrode decides the amperage
Each electrode diameter works within a current range. These ranges are approximate for general-purpose stick electrodes:
| Electrode | In inches | Approximate current |
|---|---|---|
| 2.5 mm | 3/32” | 60–90 A |
| 3.2 mm | 1/8” | 90–130 A |
| 4.0 mm | 5/32” | 120–180 A |
| 5.0 mm | 3/16” | 160–230 A |
| 6.0 mm | 1/4” | 220–300 A |
The exact range depends on the electrode type and the brand, so always check the box. Cellulosic 6011 usually runs in the lower half of the range and low-hydrogen 7018 in the upper half.
The rule of thumb: choose a machine whose rated current sits above the range of the electrode you use most. At 200 A, a 3.2 mm electrode runs comfortably and a 4.0 mm electrode sits near the limit. For 5 and 6 mm you need 300 A or more.
Step 2: the duty cycle
The duty cycle tells you how long the machine can weld at a given current without overheating. It is measured over 10 minutes (IEC 60974-1). 60% at 200 A means 6 minutes of arc and 4 minutes of rest, at 200 A.
At lower current, the duty cycle rises. The usual relation is that current squared times duty cycle stays constant. That gives the current at which the machine can weld without stopping:
200 A at 60% → 200 × √0.6 ≈ 155 A at 100%.
| Machine | Rated current | Rated duty cycle | Current at 100% (approx.) |
|---|---|---|---|
| 200 A | 200 A | 60% | ~155 A |
| 320 A (50 Hz) | 320 A | 60% | ~250 A |
With stick welding, the arc burns for only part of the shift: you change electrodes, chip slag and set up the next joint. That is why a 200 A machine on 3.2 mm electrodes works the whole day without stopping for heat. On 4.0 mm near 180 A, long runs can reach the limit.
Step 3: auxiliary power
The auxiliary outlet runs tools and lights: an angle grinder, a drill, floodlights. HTX welding generators deliver 5 kVA single-phase (GW200E and GW220E) or 4 kVA (GW350E) at 50 Hz. That is enough for a large grinder of about 2 kW together with work lighting.
Always ask whether you can weld and use the auxiliary outlet at the same time, and with how much power. It depends on the design of each machine, and it is the question that prevents the most trouble on site.
Step 4: fuel and run time
Published figures at 50 Hz:
| Model | Tank | Consumption at 100% | Consumption at 75% | Run time at 100% |
|---|---|---|---|---|
| HTX-GW220E (200 A) | 12.5 L | 2.39 L/h | 1.82 L/h | ~5 h |
| HTX-GW350E (320 A) | 30 L | 3.66 L/h | 2.93 L/h | ~8 h |
Run time at full load is the worst case, and it is the figure to plan the tank with. In a real stick-welding shift the arc is not lit all the time, so a day’s fuel stays well below hours multiplied by full-load consumption. To work out the cost with your own load, use the method in how much fuel a diesel generator uses per hour.
50 Hz or 60 Hz, and altitude
Frequency changes the output. At 60 Hz the engine runs at 3,600 rpm instead of 3,000, and the HTX-GW350E goes from 320 A to 350 A. Auxiliary power rises too: from 5 to 5.5 kVA on the 200 A models, and from 4 to 4.5 kVA on the GW350E.
Altitude works the other way. The engine loses about 3% for every 300 m above 1,000 m, and the current available at the top of the range falls with it. On a site above 3,000 m, leave more margin between the electrode you use and the rated current. The calculation is in why diesel engines lose power at altitude.
Diesel or petrol
On a building site or at a mine, diesel is the fuel that is already there, for the trucks and the machinery. A diesel engine copes better with long days, and diesel is stored with less fire risk than petrol. Petrol welding generators are lighter and cheaper to buy, and they suit short, occasional jobs.
Weight, noise and transport
The 200 A models weigh 105 kg and measure 745 × 515 × 730 mm, so they fit in the bed of a pickup. The GW350E weighs 211 kg (950 × 680 × 785 mm) and needs a ramp, a forklift or a trailer to move.
The published noise level of the GW200E is 85 dB(A) at 7 m. Anyone working close by needs hearing protection, and it is not a machine to run at night next to homes.
Welding generator, or generator plus inverter welder
If you already own an inverter welder, a generator set can power it. Find the maximum input current (I1max) on the welder’s rating plate and multiply it by the voltage. For example, a plate showing 32 A at 230 V gives 230 × 32 ÷ 1,000 ≈ 7.4 kVA. Choose a set with at least that prime rating and with a voltage regulator (AVR), because inverter electronics are sensitive to voltage swings. An 8.5 kVA single-phase prime set such as the HTX-G12K-XE covers that case.
A welding generator is one machine, rugged and with no electronics exposed to dust. A generator with an inverter gives more auxiliary power and a lighter welder to carry up a scaffold, but it is two units to transport.
What to ask a supplier
- The rated current and the duty cycle at that current
- The electrode range it accepts
- The open-circuit voltage: for cellulosic electrodes such as 6010 and 6011, a higher open-circuit voltage makes the arc easier to strike (the GW200E publishes 65–70 V)
- The auxiliary power, and whether it works while you weld
- Fuel consumption in L/h and the tank capacity
- Weight and dimensions, for transport
The three HTX welding generators
| HTX-GW200E | HTX-GW220E | HTX-GW350E | |
|---|---|---|---|
| Welding current | 50–200 A | 200 A | 320 A (50 Hz) / 350 A (60 Hz) |
| Duty cycle | to be confirmed | 60% | 60% |
| Electrode | 1.6–4.0 mm | 1.6–4.0 mm | 1.6–6.0 mm |
| Auxiliary power (50 / 60 Hz) | 5.0 / 5.5 kVA | 5 / 5.5 kVA | 4 / 4.5 kVA |
| Engine | HTX-AE188, single-cylinder | HTX-AE192, single-cylinder | HTX-AE292, twin-cylinder |
| Tank | 13.5 L | 12.5 L | 30 L |
| Net weight | 105 kg | 105 kg | 211 kg |
For fences, field fabrication and repairs with 2.5 to 3.2 mm electrodes, the HTX-GW200E or the HTX-GW220E covers the work. For structural work on 4.0 mm all day, thick plate with 5 or 6 mm, or long shifts far from fuel, the HTX-GW350E has more margin and its 30 L tank lasts longer.
Two common questions
“Can a welding generator work as a backup generator?” It can for small loads: lights, tools, a small pump. To back up a house or a business with several loads, a dedicated generator set is the better choice; the kVA size chart helps you pick one.
“Can I weld 4.0 mm electrodes on a 200 A machine?” Yes, it is within the range of the 200 A models. Near 180 A the duty cycle gets shorter, and on long runs the machine will need rests. If 4.0 mm is your everyday electrode, a 300 A machine works with more margin.
Know which electrode you use? Browse the welding generator range, then send us the electrode, your welding hours per day and the site altitude, or message us on WhatsApp. Our engineers will reply within 24 business hours with the right model.