3kW immersion off a 13A plug

alichambers · Mar 21, 2012

Hi,

I am continuing a post from previous with a new question.

I have a 3kW immersion heater that I would like to change from a (broken) central timer to a local timer. The switch is shown in the image below, circled red.

I have two options:

1. Use a TimeGuard Master Fused Spur, as below:
http://www.gil-lec.co.uk/products/H... Spur Timers/24hr Fused Spur Timer/1531897762

or

2. Wire in a 13A plug and put a 13A timer unit into the plug:
7 Day Compact Electronic Timeswitch | Timeguard 2012

My question - is wiring an immersion heater into a 13A plug bad?

Is it illegal or ill advised?Thanks,Alex

[ElectriciansForums.net] 3kW immersion off a 13A plug

TaffyDuck · Mar 21, 2012

No its not illegal although my preference would be for a fixed wired immersion. If you are talking about doing this on the Economy 7 I would point out that the timer wont work without a permanent supply unless it had some kind of battery back-up facility but thats a bit gash IMHO.

Darkwood · Mar 21, 2012

even with good quality plug and sockets you with find running them at max rated load for long duration as you suggest here will overheat the plug or socket pins, its a route id avoid as ive seen same senerio so many times with overheating and failure as a result.

alichambers · Mar 21, 2012

OK - thank you both.

I am considering the following unit:

24hr Fused Spur Timer by Timeguard

It has the spec:

Specification
- Timer Mode : 24Hr
- Setting Type : Digital
- Voltage Free Contacts : Single Pole ON/OFF
- Operating Voltage : 230V AC
- Switch Rating 230V AC : 13 amp Resistive (3kW), Inductive 6A
- Battery (Rechargeable) : 1000Hr Rechargeable
- Operating Temperature : -10 to 40?C
- Integral BS1362 Fuse & DP Switch : Yes
- Conforms to Directives : 73/23/EEC, 89/336/EEC
- Dimensions : Width 85, Height 85, Depth 38

Would this be OK to wire in directly for a 3kW immersion heater? Image of existing connection above

Thanks,
Alex

Guitarist · Mar 21, 2012

There are also wall-mounted timers which are connected between your spur and immersion heater for a lot less money.
You have 2 switches and a fused spur. You have already said that the switches are for top and bottom elements but what is the spur for? Also, you should be using heat-resisting cable to supply the elements as they will be in contact with a hot surface. As Taffy said, they need to be permanently supplied to work with a timer. Is this the case? Finally, are the switches off the RFC or does each one have its own supply from a consumer unit?
I am assuming that you have limited electrical knowledge from your questions. I'm not going to say that you need an electrician, but depending on how these switches are wired, it may not be as simple as just swopping one over for a timer unit.