# Timers on extension cord



## fourmations (10 Dec 2016)

Hi all, 

Digging out my old timers to set up my co2, have a couple of digital ones from argos, had to get the manual online to refresh myself on how to program them, I never actually used them before but a couple of my mechanical ones are bust, anyway to the point...the manual says do not use on extension cords but mine had to be on a for way gang that is fed down my cabinet, any ideas on why they should not be used? Thanks


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## three-fingers (10 Dec 2016)

Nope. I use multiple timers on extensions cords with no issues...and if I'm honest I do more daisy-chaining than I know I should! (only in my own home with low W).

Can't think of any reason why an extension cord would cause a particular issue with timers, I mainly use mechanical timers though.


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## fourmations (11 Dec 2016)

thanks, 

i use cheap mechanicals as well but the noise is annoying
do they all make that buzzing/grinding noise?

cheers


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## Carpman (11 Dec 2016)

Currently running 4 digital timers in a 4 way extension.


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## KipperSarnie (11 Dec 2016)

What is the difference between a spur socket & an extension lead except an extra fuse?
Possibly but just a guess could the cable wound in a coil cause a problem? I know they can act like a heating element with a heavy load.


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## ian_m (11 Dec 2016)

There are two main issues I can see, if extension lead is plugged into timer, the possibility of exceeding the rated load current, some timers are only rated 10A. Probably not an issue with fish keeping as biggest load might only be say 150W for lights.

Other issue, which I have seen with relays, is the magnetic fields from the "cheap" relays used in these timers interfering with each other. A lot of cheap relays used in cheap timers are not shielded are cannot be placed near each other, maybe as much as 30-50mm. Issue can be the magnetic field from an adjacent timer preventing the relay closing or more likely not opening.

Anyway in my experience cheap timers are a false economy (eg Argos/B&Q 3 for £10) as I have had many failures leading to both fish and plant losses. Read my PLC article on the timer failures I have suffered, in may years and how I fixed it with 100% reliability.
http://www.ukaps.org/forum/threads/how-to-use-a-plc-to-control-your-fish-tank-part-1.42993/

From the above link.....

I have been through so many mains time switches on my fish tank, all failing in one way or another after a couple of years use.

Over the years I have had time switches that;
- Completely die. No display, no response.
- Very commonly, just reset to 00:00 and loose all their time clock settings.
- Their internal batteries run flat, so after a power failure they don’t retain their settings.
- Sometimes fail to turn on for their time period.
- More dangerously for fish keeper, fail to turn off at end of time period or jam on. OK for air pump, no damage done, but I had a time switch fail to turn off and dumped a large amount of liquid carbon into my tank, killing both plants and fish.

I have also experimented with wireless controlled mains sockets, nice as you can get many sockets in a small space, but I have had a few socket failures, where they no longer respond to the wireless commands. Also I have also confirmed that the words “wireless” and “reliable” do not occur in the same sentence, I have had sockets working for years then randomly one day, fail to turn on (or off). I ended up dumping 1litre of macro EI solution into my tank, when my dosing time switch failed to turn off after 15minutes. Luckily as fish are not affected by high nitrate and phosphate all was well.

My most reliable time switch, I bought early 1990’s, was in fact a UK made one, by Timeguard and still works. It is just rather large. Timeguard still make & sell timers, which are highly regarded but cost £25 each.

The Timeguard is still going, just installed it on the house Xmas lights yesterday.


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## zozo (12 Dec 2016)

It probably is a safety warning, if they do not write this in the manual and you burn your house down with the darn thing. Than you have a legal issue against them.. I used to work in the IT at a Regional Education Centre, they arranged several temporary classes around the region.. So it traveled around the region a lot to install IT equiptments in classrooms etc. Because they all where mostly temporary most (ignorant) managers always wanted to do it as cheapo as possible. And installing 20 desktops in a clasroom not build for the purpose they sended me on the road with a box full of powercords and splitters . Before such a classroom is open to the public in most casses the fire department has to certify the place. Anyways using powercords, multiple powercords connected or a spliter on a powercord etc. where considered dangerous DIY solutions and the safety certificat was rejected. Even if there was no reason for it according the powercords factory specs. But each seperate loos connector is a potential spark generator too, so it's not only overload they take into concern.

But i think they probably mean, do not use a powercord on the timer to switch mutliple devices..


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