Stupid O Clock Phone Call

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kme

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In the office again.
The sodding fire alarm has gone off in the hotel; and they think it might be electrical.........

So, off I trot ( it was just getting light) ( snakehips - I`d been there, been back to `samlet, and headed back out again when I saw you ;) )......

The "fire" was actually a bit of smoke from a cooked single phase motor / water pump, which had run dry, cooked its bearings, seized, and then the smoke got out.

So I get to see an area I`d previously not known about!!!!!!!

They have an 85 metre deep well, with a 4 stage water pump in the bottom ( apparently) ; then a 600L receiver tank; with a float valve to stop the well pump if the receiver tank tank fills ( open vented).

From the receiver tank, there is a "Lowara" pressure pump, which fills an unvented cylinder to 5 bar; through a filtration system ( pics will arrive soonly). They only use this water for garden and pond purposes; though it is apparently potable.

The unvented cylinder has a pressure regulator, to turn off the Lowara pump, on achievement of the required pressure.

What had happened is this:

The pump in the well had, for reasons unknown, popped the overcurrent trip on the capacitive control/starter unit; which meant it didn`t fill the receiver tank. However, the Lowara pump was still pressurising the unvented cylinder ( pump is fed straight from a sw/fused spur) ; so no overcurrent protection to the motor. It emptied the receiver; then tried to continue pumping whilst dry............oops!

So they want to ensure it doesn`t happen again. First instance has to be a thermo-mag trip on the Lowara pump ( when the new one arrives :slap )

But I`m trying to sell them on the idea of having more sense input; and interlink between the pump systems - so that failure of an upstream device doesn`t ****** up everything downstream of it.....................

Didn`t need that today - DNO attending tomorrow at 8.00 to install new ct panel, so I have to go in, shut down IT systems, switch to generator supply, restart IT systems,( all befoe 6.30 a.m; as the kitchens have to cook breakfast for guests) ; liaise with DNO to fit their CT in such a way that I can get my new 400A 4 pole iso in there somewhere; connect into the auto changeover panel; test; and then, at a mutually convenient time, shut down their IT, switch back to main supply, and restart all the IT ( usually, at this point, their Epos system falls over :( :( :( ).

So I`m off to bed now...........................

n.b. paddler - I don`t know, and cannot safely get near the coil terminals to check, the coil voltage on the contactors!!!!!!! Might get a better possibility tomorrow, when the gen. ct. is pulled in :pray   

 
That was a thought - or maybe a water sense in the pipe between receiver & pump........

The f`in tank is almost 1500mm tall mate - with a 3" hole in the top. Low level sense might be awkward; especially as they`ve got the limit switch sitting on the top hole........

 
Make sure also there is an over pressure relief valve on the pressure vessel.

I was called to one, a domestic borehole pump where the pressure switch had failed, the pump just carried on pumping.  the tank was up to 12 bar when I got there. It was only rated for 8 or so iirc.  They only knew about the fault as plumbing fittings in the house were bursting under pressure.  As well as replacing the pressure switch I instructed them to get a plumber to fit a relief valve.

 
How about fitting a flow switch in the discharge pipe of the pump.

 
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