Is this a plausible wiring diagram for a 12V DC timer?

[doive1231]

Hi,

I want to wire up a 12V DC timer (CN101A) to turn an appliance on and off. I have the found on the internet the following wiring diagram for the timer and not being too experienced I was wondering whether it will work if I make the connections as shown:


The timer does not show + or - so I am assuming the author has successfully identified the correct terminals and completed the circuit.

However, I have found a wiring diagram for the same timer for 240V use that I think is wired differently with two wires connected on the red (outside) switch connection.



Which diagram is correct?

Thanks for any help.

 

[telectrix]

the 1st diagram is no good. you're only applying 12V to the lamp. more info on what you want to achieve would help.

 

[Guest111]

why not just use a 240v timer?

 

[Spoon]

As what Telectrix says, we need more info on what you are trying to do.

Your timer runs off 12V but can switch mains voltage (max 16A) The second diagram is incorrect for yout timer. It shows the timer wired to the mains via two fuses.

 

[cobrauk]

Is your load 12volts as well ? if so the first drawing is correct.
If the load is 230volt then you need to switch that through the contacts

 

[telectrix]

that battery ain't gonna last very long though.

 

[Guitarist]

LED lamp?

 

[doive1231]

Hello,

I am wiring a 12V DC fridge from a 12V sealed lead acid battery and I want to add the timer because the fridge does not have a thermostat and would freeze my food if on constantly. Therefore the bulb will be replaced with a fridge in the diagram and I have the DC lead from the fridge. The battery will be charged via a solar panel and the fridge connected to the load output of the solar charge controller.

 

[cobrauk]

Then your first drawing is correct m8

 

[Guitarist]

I'm surprised there's no stat in the fridge to control it's own internal temperature.

 

[doive1231]

Thanks for your help. The fridge is a small one that you can buy in Argos etc.

The diagram shows two wires at the battery's negative terminal. Is it OK to attach two wires to the negative terminal or should they be joined before and have a single wire attached to the negative of the battery (or charge controller)?

 

[cobrauk]

I cant believe that a fridge from Argos needs to be controlled via a time clock to stop it freezing m8 ?

but to answer your question it don't matter where you connect the two negatives

 

[KAS1]

I thought the Argos fridges were dual voltage mains or car, if so use a mains timer, I may be wrong again today though

 

[doive1231]

Yes, the fridges are dual voltage and I use a mains timer for AC but I want to run it off grid, hence the DC timer.

The fridges are surprisingly powerful and will freeze milk and food very quickly.

 

[Spoon]

I have a small fridge from Argos at work, for my milk for my brews. It doesn't freeze the milk.

 

[tazz]

I would used a electronic stat with lead sensor, the fridge will be at the temperature you require then

 

[Darkwood]

Has no-one noticed the first diagram shows a supply 12v AC........ check out the waveform symbol in brackets... you DC supply from the battery may not work although some power supplies are not waveform conscous and will work off either.

Here's an easier diagram to follow but do note the pic is reversed from yours.

 

[guinnessgixer]

I would of thought if there is no stat on the fridge, the compressor and system isn't powerful enough to freeze anything even running constantly?? surely it would be a hazard to health??

 

[FrankUK]

Just use a replacement fridge stat by Ranco. These are specially made for the job. The Varifix range. Ranco Varifix Service Thermostats

You can buy these off the shelf from any local fridge wholesaler, such as Climate Centre, FSW, HRP, Dean & Wood etc. They are also available off ebay.

They are a temperature switch, so will switch whatever voltage you have in your compressor control circuit.

They make about 10 different versions for different applications, i.e. high temperature, freezer, bottle fridge etc. Just make sure you tell them exactly what you want it for and they will select the correct model.

 

[FrankUK]

Has no-one noticed the first diagram shows a supply 12v AC........ check out the waveform symbol in brackets... you DC supply from the battery may not work although some power supplies are not waveform conscous and will work off either.

Here's an easier diagram to follow but do note the pic is reversed from yours.

I noticed the RMS waveform symbol and thought it better to post the information above, as this may prove to be more helpful.