Commercial dishwasher heater element

[happysteve]

Wiring diagram in case you were interested!
View attachment 27491

Is that a fuse in the N (F2)? Is that sort of thing normal? Just interested...

 

[Bobster]

According to the drawing its a 4A fuse, not normal.

 

[happysteve]

Thanks.

I'm trying to think of a situation on an installation, control gear or equipment where a fuse in the N might be needed or justified. I'm stuggling.

I suppose it could protect the upstream (where "up" is "closer to source of energy") cabling, e.g. if there was a possibility of the N downstream of the fuse being in contact with a line conductor that has not been fused down itself. But this seems very convoluted!

There was a thread about fused neutrals a few months back (can't find it), I can't recall the reason why N used to be fused at the service head in the old days (if there ever was one!).

 

[Bobster]

It originated in the days of DC transmission, people at the time saw it as being the safest option (they were proved wrong).

I can't think of any reason off the top of my head why a neutral would be fused, it's quite common to have the 0V/Neutral in a control panel to have a drop link fitting,. This is only to aid in testing.

 

[Marvo]

The only time I can think of for a fused neutral is if there's a chance the supply polarity could be reversed.

Maybe they did it here to limit surge currents through MOV's to earth. It's a curious and very unusual arrangement.

 

[pennychew]

Just posted but it didn't appear? unless i clicked the wrong button!

Is the fused N not something to do with the item at T1?

The Guys sent me the quote from the service agent and it was a faulty PCB causing the drain pump to run continuously, nearly £500 for the part alone when i checked some parts websites so let them crack on!

 

[Bobster]

T1 is just a power supply, converting AC to DC, doesn't state the voltage.

 

[pennychew]

I know which part that was now, it was supplying a small motor that changed the angle of the rinse bars