What type of Relay to use?

Other Hardware General Electronics
1

Hello. Noob question (again)
If a device runs on a 240v power supply with a 13A fuse, does this mean that the cables inside it will be carrying 240V?

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Do I need a relay that can handle 240v or is it going to be a different voltage due to the cables being inside the device?

I have contacted the manufacturer and they said they will get back to me within two days.. I was planning on completing it this weekend.

I have no multimeter.

2

a device runs on a 240v power supply with a 13A fuse, does this mean that the cables inside it will be carrying 240V?

for safety consider it yes.Even if it run at less voltage it will be more safety

3

Probably depends somewhat on what you mean by "power supply." My laptop runs on a 120V A/C power supply, but the "power supply" is a transformer that sits outside the laptop. So, up to the power supply (my definition, in this case) the voltage is indeed 120V, but beyond the PS (i.e., the wiring inside the device) it is 19V (and various lower voltages, too).

If you're device is an appliance that plugs into mains power, and you don't know for certain otherwise, the safe assumption is that it's 240V. But if you're uncertain, it's perhaps ill-advised to be modifying the device...

4

Yes, ill advised indeed. I have a 220/250v AC5A relay. do I need a 13A instead?

5

You are apparently in UK.

Does your device have the big UK plug, fused for 13A? If so, that is simply the PLUG standard.

You need to find the power rating of the device. What IS it? The photo looks like maybe a coffee maker (Or Tea - Sorry!)..

If the CURRENT used by the device is less than 10 amps, the typical small relay board that can be controlled by Arduino would be adequate. (This IS an Arduino control question? What do you want to accomplish?)

Look at the ArduinoInfo WIKI here - http://arduinoinfo.info and read about Power Control with Arduino here:
http://arduino-info.wikispaces.com/ArduinoPower

This kind of relay may be OK: http://goo.gl/PcWJ2

DISCLAIMER: Mentioned stuff from my own shop...

6

I'm controlling it with the arduino with a relay. Yes.

I found the following information about the device

Input power W 1000
Rated voltage/Frequency V~Hz 220-240/50-60

I have a sparkfun beefcake PCB coming in the post just in case. It seems useful to have one sat around.

I buy all of my stuff through proto-pic.co.uk. They are very helpful.

7

To work out Amps (A) divide watts (W) by volts (V)

A = 1000W / 240V
A = 4.17A

8

That's true.
The basics escape me today. Got a cold coming or something.
Thanks for the help.