Technical data for instant water heater you must know, which will help you make a best choice.
1st, every area or countries have different voltage.
Almost the whole america areas both North America and South America use 110V single phase tankless water heater. While in Europe, Africa and Asia, it is 220V to 240V single phase electric instaneous water heater. Meanwhile, different voltage has different power. Please check below table as reference.
2nd, facing so many different powers for electric tankless water heater, which one fits for you？
The power under 6.5kw or 5.5kw is used as one point solution for sink or shower. While power up to 8.5kw could use for multiple points, not only supply for hot water hand wash but also supply for bathroom water heater.
3rd, another very important point of electrical specification for instant hot water heater.
It is about the fuse or circuit breaker that every shower unit required to have one. Please be noted that either fuse or circute breaker has minium size for each kilowatt rating.
3.0kw to 4.5kw : 25 Ampere
5.5kw to 6.5kw : 32 Ampere
7.5kw to 9.5kw : 40 Ampere
4. Make sure the water pressure in your household
The mini start water pressure is 0.02 Mpa / 0.2 Bar, the max water pressure is 0.6 Mpa / 6.0 Bar
5. The start water flow for electric geyser is 1.2L/Min or 1.5L/Min, which is depend on your local condition.