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.

[moved] Specify power supply fuse rating and maximum allowable input current?

Status
Not open for further replies.
T

treez

Guest
We wish to design a electric car battery charger for connection to single phase , 230VAC mains. Therefore the maximum input current that we are allowed to draw is 16 Amps. However, this must be fused. The fuse must be rated 16 Amps or less for use on single phase mains. The maximum input current has to be at least 10% less than the fuse rating to avoid false fuse tripping. Therefore, the maximum input current we are allowed is 14.4 Amps.
Therefore the maximum input power that we can design for is 230VAC * 14.4A = 3312W. With an efficiency of 90%, this means our charger output can be no more than 2.98kW , due to its connection to single phase mains. Do you agree?
 

Re: Specify power supply fuse rating and maximum allowable input current?

the calculations agree with the goal.
is the pf of the proposed system known ?
 
  • Like
Reactions: treez

    T

    Points: 2
    Helpful Answer Positive Rating
Re: Specify power supply fuse rating and maximum allowable input current?

We can't find the regulations for level of PFC required above 1kw?
 

We can't find the regulations for level of PFC required above 1kw?
Is an electric car battery charger considered as professional equipment? Otherwise EN 61000-3-2 (IEC 1000-3-2) class A harmonic current limits apply.
 
  • Like
Reactions: treez

    T

    Points: 2
    Helpful Answer Positive Rating
Our bought-in offline battery charger (uk mains), on its datasheet, states that it "makes full use of the 16 Amp limit of single phase mains," but then in the datasheet they say they have "electronically limited the input current to 14 Amps".......surely If they are making "full use", then they should be drawing the full 16 Amps, and electronically limiting to higher than 14 amps?
Why have they limited to 14 Amps?
Is 14 A the maximum legal limit of single phase mains?
 

Is 14 A the maximum legal limit of single phase mains?

I do not know legal specifics, but for a while in the USA, aluminum wiring was installed in homes. It has a different coefficient of expansion from copper. Yet aluminum wire was routinely joined to copper using screw connectors and twist connectors. Over time, connections tended to deteriorate, generating heating effect. Fires were known to result. So we returned to copper wiring as the uniform practice.

This could be a practical reason for an Ampere limit, to prevent overheating of wire connections in the walls.

Additionally, extension cords are a weak link, especially if they are flimsy. Both wires and plug connectors can heat up.

15A is commonly the spec maximum that I've seen printed on electrical parts used for mains 120VAC.
 
  • Like
Reactions: treez

    T

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

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top