W
wade88
So i have noticed a fair amount of unhappy posters this last couple of weeks, thought i would throw myself out there as the sacrificial goat of comedy and try to raise some smiles amongst a few of you...
And so, long story cut embarrassingly short, we have this large mixing crucibal here at work 9ft high, 1 tonne capacity, pretty basic stuff, 7.5 kw 3ph motor, 3 heating bands around the mixing bowl on separate phases circa 15kw of heating all in all.
Night shift supervisor comes to me in the morning last week as i get in, bit sheepish, says
"Ben, the control panel to the mixer sort of....well....blew up last night, smoke was pouring from the vents and there was a huge bang" .... *SIGH*
What utter foolishness has one of these numpties done to it now...so i open the panel up and sure enough, the incoming 6mm tails have burnt away, flash burn every where, and the din terminals have completely broken apart like a grenade went off in there. My guess was after the machine has been moved around a bit and this control panel dragged along behind it, terminations came loose and some serious arcing had been occuring until it finally went. So i replaced the tails, replaced the din rails connectors, checked other fuses, ran around with volt meter for a while to just see what was what and all seemed well...
Turn on machine heaters *BANG*.... all goes again, traced voltage back to the point it stops and first phase cartridge fuse downstream of contactor goes down as soon as i select heater band 1....scratched head for a while....figured maybe the SSR took some damage during the initial 'blast' and figured id just replace it from stores anyway. So i disconnect the heaters to take all load of the circuit to see if they were the problem, try again *BANG*, check cable insulation, fine, checked just about everything and was just walking off to get megger when i noticed this......
Now, im ready for the assault here, but in my exp, which we have established lately is limited but i dont feel poor, i am use to the disconnection tab of most MCB's and DIN terminals to be at the bottom, so, when i replaced the damaged DIN T's for the incommers, i automatically just put them in this orientation without a seconds thought, turns out the panel builder had put them in the other way around, so being insulated on one side only and the terminals exposed on the other, i had unknowingly slotted the N incommer terminal next to the first phase of the heaters the other way around so they were just snuggled up, zinc to zinc.....every time i turned it on, dead short and pop.
After some hours, one or two phone calls, and changing over system components that were absolutely fine, it turns out, i was just a massive dork.
Maybe you had to be there...but i had to laugh
And so, long story cut embarrassingly short, we have this large mixing crucibal here at work 9ft high, 1 tonne capacity, pretty basic stuff, 7.5 kw 3ph motor, 3 heating bands around the mixing bowl on separate phases circa 15kw of heating all in all.
Night shift supervisor comes to me in the morning last week as i get in, bit sheepish, says
"Ben, the control panel to the mixer sort of....well....blew up last night, smoke was pouring from the vents and there was a huge bang" .... *SIGH*
What utter foolishness has one of these numpties done to it now...so i open the panel up and sure enough, the incoming 6mm tails have burnt away, flash burn every where, and the din terminals have completely broken apart like a grenade went off in there. My guess was after the machine has been moved around a bit and this control panel dragged along behind it, terminations came loose and some serious arcing had been occuring until it finally went. So i replaced the tails, replaced the din rails connectors, checked other fuses, ran around with volt meter for a while to just see what was what and all seemed well...
Turn on machine heaters *BANG*.... all goes again, traced voltage back to the point it stops and first phase cartridge fuse downstream of contactor goes down as soon as i select heater band 1....scratched head for a while....figured maybe the SSR took some damage during the initial 'blast' and figured id just replace it from stores anyway. So i disconnect the heaters to take all load of the circuit to see if they were the problem, try again *BANG*, check cable insulation, fine, checked just about everything and was just walking off to get megger when i noticed this......
Now, im ready for the assault here, but in my exp, which we have established lately is limited but i dont feel poor, i am use to the disconnection tab of most MCB's and DIN terminals to be at the bottom, so, when i replaced the damaged DIN T's for the incommers, i automatically just put them in this orientation without a seconds thought, turns out the panel builder had put them in the other way around, so being insulated on one side only and the terminals exposed on the other, i had unknowingly slotted the N incommer terminal next to the first phase of the heaters the other way around so they were just snuggled up, zinc to zinc.....every time i turned it on, dead short and pop.
After some hours, one or two phone calls, and changing over system components that were absolutely fine, it turns out, i was just a massive dork.
Maybe you had to be there...but i had to laugh
