I need to run a couple of 20-50w submersible aquarium pumps for hydroponic systems in the garden.

Would it be safe to run an extension from the external outlet to a watertight 50l storage box, and plug both pumps into that?

 

Do I need to install an RCD or something? If I do, I'm in a rental property. Is there a way to do that fairly cheaply?

How dangerous would it be to have one of the cables laying on the grass where it is in danger of being damaged?

I'm not an electrician (you can probably tell) so please keep it fairly simple for me.

Thanks!

I would certainly place an RCD at the feed end of your cable to avoid the danger of death if you run over the cable with the mower. Personally, I would route the cable to avoid the risk of damage.

 

Plug-in ones are available or get one of the low-cost RCBO devices and a small box for it and stick it on the wall next to your outlet.

 

Something like this (cobwebs/spiders not necessary) : -

 

I have seen some plug in ones on Lazada for about 250 Baht,

They seem to be a plug in version of the permanent ones in CU's

They have a test button which gives some measure of confidence. 

Don't know how good they are but probably ok,

9 hours ago, Muhendis said:

Don't know how good they are but probably ok,

For 10 bucks, I doubt it.