There are several factors which can cause problems with the life of Hypertherm consumables in a plasma cutting system and troubleshooting these problems is not only time consuming but complicated too. Here are a few common things to consider when you are facing problems with your plasma cutter to ensure that you’re getting the most out of your plasma torch. Some of the things to look for if you are experiencing reduced nozzle life or plasma electrode life are:
Reduced Coolant Flow
The electrode usually produces a lot of heat and if the cooling fluid is not sufficient to dissipate the heat, the electrode will heat up very quickly and this will result in catastrophic failure, which will require the replacement of the nozzle, electrode, electrode holder and other components that may be damaged in the process.
Reduced Gas Flow
The plasma gas not only constricts the plasma arc but also helps to cool the nozzle and the thin layer of cool gas prevents the nozzle from melting quickly. If the gas flow is not adequate, the nozzle’s interior heats up very fast and melts causing the premature failure of the torch.
Wrong Pierce Height
When the torch pierces, a large amount of molten spatter is produced. If the plasma torch is very close to the workpiece while piercing, the spatter can come in contact with the nozzle and/or the shield and can result in double-arcing or melting. The plasma system requires a height control system that sets the proper pierce height.
Crashing the Plasma Torch
The plasma torch can crash due to many reasons such as when the workpiece pops up, when some part tips up or if there is slag on the top of the plate that causes obstructions. Ideally, the CNC cutting system should shut down the plasma arc automatically in the case of a torch crash; however, sometimes the damage cannot be avoided. If the nozzle comes into contact with the workpiece while cutting, it may cause double-arcing or it can cause the orifice to be damaged.
Wrong Current Setting
Most of the modern plasma cutting systems set the cutting current automatically. However, in the case of a manual system where the current is set manually, the wrong current setting can cause the nozzle to be damaged and reduce the nozzle life.
Contaminated Gas/ Water
Any kind of impurities present in the plasma gas or water can cause deposits to be formed inside the nozzle, causing double-arcing, resulting in nozzle damage.
Wrong Cutting Parameters
Modern plasma cutting systems require many settings such as kerf width, cutting speed, amperage, gas pressure, arc voltage, pierce time, gas flow rate, etc. In order to simplify the process of setting all these parameters, plasma cutters make use of a database that is inbuilt into the CNC, which allows the operator to select the parameters required and all the other settings are adjusted automatically on basis of the parameter set selected. However, selecting the wrong parameter set for the particular nozzle and electrode can cause problems.
Using incorrect consumables such as the wrong nozzle, etc. can reduce the Hypertherm consumables’ life significantly although the parameters that you choose may be correct.
Using the wrong type of coolant can reduce electrode life similar to when the coolant flow is low. Avoid using additives and anti-freeze solutions as this will harm the torch and the pump. You can maximise electrode life by mixing the plasma torch coolant with pure water as this is the best to dissipate the heat from the electrode. Sometimes, using higher glycol percentage offers better freeze protection, which may reduce the electrode life, but may be required depending on the plasma cutting system’s environment.
Avoiding these mistakes when using a plasma cutting system can go a long way in increasing the life of the torch, the electrode and your Hypertherm consumables, increase productivity and reduce consumable wastage and downtime.