CATERING: salamander grill elements??

cateringENGINEE · Dec 29, 2014

hi new to this site..
i have a 8 element 3kw grill thats elements keep blowing after a few days...

the elements should be 375watt 240v. totalling 3kw

im thinking they shoud have a 154 ohm resistance

my boss ordered new elements telling me they are 110v 360watt, just put them ones in.....

i tested the resistance and it come to 40 ohms so that to me running at 240v works out at 1440 watts and would trip the breaker or blow the element.

40 ohms at 110v i work out is 360watts.... ive put them all in turned it on and its been running fine for hours??? both banks of 4 elements are pulling 6.9amp so that all seems good. i expected a lot higher current and for it to blow the elements..

ive obviously mis understood or worked it out wrong here..
any explanations would be appreciated

snowhead · Dec 29, 2014

Series /parallel?

Deleted member 26818 · Dec 29, 2014

I imagine that the elements are wired in series, so that two combined will equal 220V.
This is similar to how Christmas tree lights were wired, 20 X 12V lamps equals 240V.
Also the elements will only draw as much current as they require.
Whilst the current drawn may exceed the rating of a protective device and cause it to blow, it should not cause the elements to blow.
Over voltage would be expected to cause damage to the elements, if they are not wired in series.

telectrix · Dec 30, 2014

and be aware that the element's resistance will increase as it heats up, so the cold resistance will give you a higher calculated current.there may also be an inductive component of the total reactance.

cateringENGINEE · Dec 30, 2014

Thanks for the informative replys, that explains a lot. There is 4 banks of 2 elements wired in series so the 110v + 110v makes sense to me now..
So with me putting as I know now to be the correct elements in why would you think after so long the elements blow?
You say an over voltage would cause it but how would an over voltage occur?? If the voltage is 240v how can it be higher? Or is there anything else I could look into as to why the elements would blow?

Thanks