Sparking switch. Am I going to fry?

[snowman070]

Hi all,

I've just put in a double pole isolating switch for a water heater. The switch is one of those 45A oven switches with the red button and the heater is 10.8 kW.

Problem is, if the switch is turned OFF whilst the heater is running there is an almighty spark that lights up the inside of the switch. Strangely, when the switch is turned ON (with the heater running) there is no spark.

Is this normal? I'm a bit concerned about getting fried and leaving the wife and kids with yet another unfinished DIY job.

 

[Taylortwocities]

If the load is connected then you will get a spark. The bigger the load then the bigger will be the flash.
After a while the contacts will burn out but that shouldn't cause you a problem (only need to install a new switch)!

Why do you need to keep turning it on and off?

 

[snowman070]

Thanks TTC, I take it that you are saying that the sparking is normal behaviour and not something dangerous or a fault?

I only turned it on and off to check the connection and got concerned about the sparks. In normal use it would be left on all the time.

 

[RF Lighting]

It's normal. As TTC mentions, the bigger the load the bigger the spark.

10.8kW is right on the limit for a 45A switch. Personally I'd have fitted a 50A switch.

Here's a proper spark when a switch opens.
http://www.youtube.com/watch?v=hIkNY5xjy5k

 

[AdamCH]

Maybe go for something like this:

View media item 56751

 

[snowman070]

I'll source some green slime for my fusebox!

Thanks all.