Low cost RCD testers produce a fault current which will vary if the supply voltage varies. Higher cost RCD testers have regulated trip currents (or constant current circuitry), which maintain an exact fault current regardless of the supply voltage.
Some very low cost RCD testers do not test accurately, may burn-out, or may create irregular fault currents, which do not trip all types of RCD. We have thoroughly tested all of the RCD tester models we sell to ensure accuracy, quality and performance.
Always ensure an RCD tester is sold with a manuafacturers certificate of conformity or certificate of calibration.
