megaflo immersion wiring question

[sajeel]

Hi,

Recently i went to diagnose a customer who was getting massive electric bills and the hot water was not heating anymore, i found that the customer switched on immersion backup on megaflo and left on this melted the 13a spur and cracked due to constant load of 3kw which is over 13a, there is no mention in manual how this should be wired, but i would have wired this straight from 16a mcb into a double pole switch due to load and stop meltdown, i know the immersion is a backup and should not be left on constantly but we all know what happens ?

 

[Jadele]

what is the question?

 

[JohnD]

perhaps the question is "should an immersion heater be wired into a Ring Final Circuit"

Answer: No.

It probably has nothing to do with his other question, coincidentally also about an electric water heater with a massive bill.

//www.diynot.com/diy/threads/water-heating-advice.475037/

I think Sajeel is working in the plumbing business.

 

[sajeel]

Then how would you wire as cookers and ovens are wired straight to mcb fuse and they are 3kw plus ?

 

[Echo the husky]

Then how would you wire as cookers and ovens are wired straight to mcb fuse and they are 3kw plus ?

Like this:

would have wired this straight from 16a mcb into a double pole switch

A normal immersion element connected to a normal supply will draw about 12.5A not over 13A. It should be OK to run it from a (decent) 13A plug and socket without problems, but of course it is not recommended.

 

[sajeel]

I disagree 3000/230= 13.04A and that is why the spur cracked and melted see spur it not rated over 13a so you need to do this another way

 

[JohnD]

flex outlet, and a 20A DP switch with neon, on a 16A dedicated radial circuit.

simples

 

[sajeel]

perhaps the question is "should an immersion heater be wired into a Ring Final Circuit"

Answer: No.

It probably has nothing to do with his other question, coincidentally also about an electric water heater with a massive bill.

//www.diynot.com/diy/threads/water-heating-advice.475037/

I think Sajeel is working in the plumbing business.

Actually john i work as a maintenance engineer if you must know, if your such a smarts ass then answer the question how do you wire up your megaflo installs ?

 

[sajeel]

w

flex outlet, and a 20A DP switch with neon, on a 16A dedicated radial circuit.

simples

Thank you that was what i wanted to confirm and mentioned in my question this was wired off sockets feed, then into spur 13a, in fact nearly all the megaflo installs have been like this or similair.

 

[Echo the husky]

Immersion elements are rated 3KW at 240V, they will draw less current at a lower voltage. The 13A rating of plugs was specifically chosen to allow the connection of 3KW loads. I always use a clamp meter to check they are running and have never measured more than 12.7A

 

[sajeel]

i have seen too many plugs crack with loads of 2.5kw to 3kw on there so i disagree you can use plugs for this purpose but as i said a mcb 16a then use 20a double pole isolator would be the way i would have wired up.

 

[sajeel]

I think john is working in the i like to moan business