What is the difference between single-phase relay protection testers and three-phase relay protection testers?

The single-phase relay protection tester is a single-phase input and single-phase output. Within the single-phase range, the current is adjustable, the voltage is adjustable, and the AC and DC fixed voltage outputs are equipped with a millisecond meter function, and the action time of the relay can be measured. The three-phase relay protection tester is a single-phase input and three-phase output. The most common is that it can output four phase voltage and three phase current, with a maximum voltage of 125V/phase, a current of 30A/phase, and a parallel connection of up to 90A. The phase and frequency can be adjusted, mainly for testing various relays and protection devices. Three phase relay protection can replace single-phase relay protection, but single-phase relay protection cannot replace three-phase relay protection. In terms of price, three-phase relay protection is much more expensive than single-phase relay protection.