Is it safe to use a water pump without a ground wire?

Question

I am using a submersible water pump whose plug has only 2 prongs. I'm assuming the third 'ground' prong is missing. I also doubt if there is any fuse or circuit breaker inside it as it is an absolutely cheap and unmarked pump.

I want to use it to supply a garden hose which involves putting the pump in a bucket full of water. The elaborate system which I plan to use involves a whole network of PVC pipes which is connected to this hose.

Can anything go wrong or can a fault develop after lots of use which can give me a shock?

Also what precautions must I take?

Answer 1

Alright. Your first problem is the "cheap and unmarked" part -- two prong appliances can be safe, but only if they are "double insulated" or Class II. Such an appliance will have a square-within-a-square symbol on its model number label, alongside any testing marks that may have been applied.

Since this pump of yours lacks any independent equipment testing, labeling, or listing, I wouldn't trust it to not shock you any further than I could kick it. A dedicated residual current device/ground fault interrupter designed for personnel protection (i.e. 5mA trip threshold, nominal, with trip timing as per UL943 Class A or your country's equivalent standard) would be highly recommended in this application; even if the pump does try to zap you, the RCD/GFI would trip and cut off the current before a serious shock could take place.

Also, next time -- please don't get the cheapest pump you find at the bottom of the barrel! Cheap, unlabeled crap is cheap, unlabeled crap because of the safety-compromising shortcuts that are taken during design and manufacture.