Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

Immersion heater (for domestic 5kW water boiler) schematic

Status
Not open for further replies.
T

treez

Guest
Hi,
Does anyone have this, we need to check if we can just put 240VDC into it.
 

Sort by date Sort by votes
My immersion heater is only 2kW but it boils water in 5 mins (a bucket is approx 20L). My bathroom geyser is 3kW and it is storage water type. 5kW heaters are often used for instant water heaters but they are not popular because most domestic lines (house wiring) is NOT rated for 20A. The heater is a very simple construction: a brass tube having a nichrome coil and packed with Al-oxide (or is it Mg-oxide?). You can put 240V DC/AC does not matter, but perhaps if you apply power for more than a few minutes, it may melt (these are designed to work with a thermostat).
 
  • Like
Reactions: treez

    T

    Points: 2
    Helpful Answer Positive Rating
Upvote 0 Downvote
Thanks for you valuable insight on this, you have got me thinking...., i would have thought that since the thermostat will be switching the power off if the heater gets too hot, then it surely needs to be supplied with AC?......because breaking DC current at high voltage is problematic with regard to arcing in relay contacts etc?

So do you agree that an immersion heater will, of necessity, be supplied with AC, and not DC?
 

Upvote 0 Downvote
treez said:
So do you agree that an immersion heater will, of necessity, be supplied with AC, and not DC?
Click to expand...
Yes, it depends. If you are using a bimetallic thermostat, then certainly you should use AC to drive the heater.

Switching on and off frequently at 240VDC at 20A or so needs no mean relay. Even regular house circuit breakers have magnetic coils to extinguish arcing. But I have seen many lab hot water baths use transistors to switch on and off.

I have also seen PWM being used in lab water baths to control temp.

But instant hot water (that uses 5kW heater) can save power because it heats just the amount of water that is about to be used- nothing more nothing less.

But I have not see their anatomy. That may be interesting because it need to adjust the temp as a function of flow rate and temp set point.
 
  • Like
Reactions: treez

    T

    Points: 2
    Helpful Answer Positive Rating
Upvote 0 Downvote
Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top