What should be the Standard Voltage tolerance?

In any type of heater, if the voltage tolerance is on the lower side with respect to the voltage within which the heater was actually designed then there is no problem.

But, for higher voltage tolerances it depends on the watt density on the basis of which the heater is designed.

If the heater is designed with maximum permissible watt density, then no voltage fluctuation tolerance is possible and on the other hand, if the watt density is lesser than the maximum permissible watt density, then 5-10% higher side voltage is fine.

How much is the life of the heater material?

Life of heater: Our heaters are made from finest quality raw material to obtain maximum life up to many years but still life of heater also depend on application and operating parameters. So we can’t predict life of heater.

Why heater fails in hard water?

Heaters fails due to scaling on heater which generates due to use of heater in hard water. Scaling (deposited sediments on heater) forms a layer on heater tube which acts as an insulation which in turn melts the heater outer sheath due to improper heat transfer. 

What is the maximum voltage rating on which exciter heater can operate?

We can operate heater at any rated voltage, the difference would be only with the wattage as power is directly proportional to voltage as the voltage increases power will also increase. If power will increase watt density of heater also increase but watt density should not cross of a heater maximum limits.

How to achieve long life of water heater?

1. Use of distilled water
2. Cleaning of tank and heater on regular basis.
3. Removing of scaling from heater by dipping it into acid.
4. Clearing water from tank and run anti scaling fluid which reacts with scale and removes it.