The ZRID protection system is a RCD (safety switch) on the secondary side (output) of the welding machine.
Being a true Deadman Switch with the assurance that on breaking the weld, the electrode automatically drops to zero-volts and cannot re-strike until reinitiated via the trigger.
A Deadman switch is defined as:
"a safety feature integrated into many machines which works to the machine off if the operator experiences a problem." (WiseGeek)
"a switch that is automatically operated in case the human operator becomes incapacitated, such as through death or loss of consciousness." (Wikipedia)
The trigger is the most successful hazard control device in history for human hand control.
The first step in the hierarchy of risk control/management is to eliminate the hazard, which in this case is electricity.
OH&S is the law and it is recommended that the welding machine be switched off every time the welder is not welding, but this can become a tedious task for the welder especially if working in positions above or below ground and far away distances from the machine.
For boilermakers who are exposed to the invisible electrical hazard on a daily basis, greater protection is required.
ZRID, being the first patented technology worldwide, addresses this by providing a zero-volt OCV on the electrode holder. This reduces the electric shock hazard when changing electrodes especially in
welding Categories B and C (wet or confined spaces).
Self-Test and confirmation after every weld completion
Accidental arc-ray flashes are present in welding on a daily basis where the welder unexpectedly contacts the workpiece or structure with the electrode. With the ZRID system installed the electrode is 'dead' by automatically de-energising the output of the welding machine when not welding.
This hazard can cause temporary blindness to the welder or observer and over time can lead to a loss of sight. Temporary blindness could result in secondary accidents such as trips, falls, or the live electrode hitting a flammable area/pipe which could have a catastrophic effect.
zRID protects the operator and the workplace when not welding
zRID devices do not dictate the value or produce any full open circuit voltage (OCV), but are designed to switch off existing OCV on welders.
With a manual ON and automatic OFF, the zRID acts to make the machine weld so; it's NOT working when you're not welding.