problem with 60 amp fuse

[easilec]

I changed two fuse boards in a house that is converted into 6 flats, these 2 boards control the communal lighting, which work on PIR sensors, so are never left on for long, they also control the fire alarm, emergency lights and the immersion heaters, one on each board.
So in each fuse board we have a 32 amp ring, a 16 amp water heater circuit, a 16 amp radial socket circuit and 2 lighting(6 amp) circuits.
When i turn the power on everything is fine, but then when i leave the job, an hour or so later i have the landlord on the phone saying nothings working, when i go back the 60 amp fuse has blown, but it seems to take an hour or 2 to blow, can anyone shed any light on this for me as i've been back 3 times now and am going out of my mind.
thanx, james.​

 

[easilec]

Tony mc this is correct, nothing else trips

 

[sedgy34]

Tony mc this is correct, nothing else trips

whats the earthing arrangement and ze

 

[SPARTYKUS]

EWell there is a clue.....

If its just the main fuse then don't you think there must be a problem betwixt fuse and....board!

 

[SPARTYKUS]

Easilec whereaboooots are you West Mids? I'd be happy to help

 

[tony mc]

So start looking between the boards and the fuse first IMO

 

[sedgy34]

the supply cable needs to be verified here!

 

[Knobhead]

Why???

 

[sedgy34]

Why???

i think you asked why to my comment, supply cable from the 60a fuse to CU,s

 

[GLENNSPARK]

IR test between poles on the DP switches.....check main earthing...see how much currents on it.....

 

[GLENNSPARK]

also....hang around for a bit....see if the current draw suddenly jumps up....as if theres a "secret load" anyware..lol....

 

[Knobhead]

i think you asked why to my comment, supply cable from the 60a fuse to CU,s

You didn't make it very clear.

 

[lamb]

I would check the connections on the cutout/ryefield fuseholders that hold the 60a fuses that keep blowing.
If there is heat build up here due to loose terminations/fuse blades/contacts the heat could melt the fuse wire with only a few amps flowing.
By the time you return to site the fuseholder will have cooled down so you would never know.

 

[Knobhead]

A quick way to check for heat build up is the temperature sensing labels sold by RS. I’ve used them on fuses before. Will have a look for them later, busy cooking at the mo.

 

[GLENNSPARK]

A quick way to check for heat build up is the temperature sensing labels sold by RS. I’ve used them on fuses before. Will have a look for them later, busy cooking at the mo.

your always bloody cooking Tony...lol...

 

[SPARTYKUS]

A quick way to check for heat build up is the temperature sensing labels sold by RS. I’ve used them on fuses before. Will have a look for them later, busy cooking at the mo.

I bet it isn't Puy lentils in creme fraiche and white wine, salmon baked with lemon and garlic, new potatoes, 10 minute old asparagus and roast parsnips coated in butter???