Solenoid valve

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Dr_Doggy said:
thanks, i think we are right about the presusre, im gonna get some grav feed , hopefully they work better.
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I've always been surprised by all the water towers shown in small town America (obviously to increase water pressure via gravity), but they are really very rare in the UK - I know of one that's fairly local. Might be because I live in a hilly part of the country - we've still got purely gravity fed underground aquaducts that were built in Victorian days, and still working perfectly, running many miles from reservoirs to cities.

Also Nigel , what not use a locate set?
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That's what it is - what kind of 'locate set' were you thinking of?. The audio hammer method is usually used for plastic pipes (so anything modern) while you can metal detect for old metal pipes of course.
 
K wait ima step back a sec here,
so my hydroponics has a chemical mixture of ph 6.0. I run it through regular fountain pumps and have never seen any "meltdown"

but another project where i am using some cheap 12v china pumps circulating a water & cider vinegar solution 50:1 is supplying water to my rabbits. The pumps always struggled and stalled since the launch of this device. but after 2 weeks they are completely dead, i assumed it was a pressure thing. today we found a cloged line and when we pulled the coupling apart we found what was like a black gummy worm. In retrospect I have a feeling the black worm was a rubber part inside of the pump.

post 20 is another pump i need to lift the rabbit urine the 20 ft but does not need a high flow rate, only a few litres per hour, but im worried for the pump if its soaking in a bucket of urine even when off.
 

The water companies use a number of different methods for detecting and tracing pipes, and different methods work better in different cases, with plastic pipes been particularly difficult.
 
It's a pity all plastic pipes intended for domestic central heating and water distribution aren't provided with a moulded-in electrically conductive strip to make location easier.
 
alec_t said:
It's a pity all plastic pipes intended for domestic central heating and water distribution aren't provided with a moulded-in electrically conductive strip to make location easier.
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I recall many decades ago, in the UK everyone that was connected to the local water facility had a metallic supply service.
This was used for the earth ground reference, once these were replaced with non-metallic supply, RCD's became mandatory.
 
MaxHeadRoom78 said:
I recall many decades ago, in the UK everyone that was connected to the local water facility had a metallic supply service.
This was used for the earth ground reference, once these were replaced with non-metallic supply, RCD's became mandatory.
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That was simply because all water pipes were metal - and originally were lead.

But even so, the earth reference of the houses was normally a ground spike, and not the water pipes - the water pipes (and gas pipes as well) were connected across to the houses earth, to ensure that all pipes were at earth potential, just as they are now. I don't believe the RCD requirement has anything to do with it, as the earth shouldn't have been via the pipes anyway - and an RCD doesn't remove the requirement for an earth connection (in fact it requires one to work).

It's still the same now except often a PME earth is used (earthing via the incoming neutral), and even more care is taken to ensure all metal pipes are bonded to earth.

There's been a BIG infrastructure update over the last few decades, with gas supplies been changed from (rusting) metal to plastic, usually with the plastic pipe slid inside the old metal one.
 
The RCD came about because of the lack of guaranteed favorable earth ground on the introduction of PVC piping., prior to this, we had water piped in with underground steel pipe after switching over from a well.
At the time I was involved, the neutral was not allowed to come in contact with the earth conductor at the installation, even at the panel, as it is done in N.A.
The only place the neutral was bonded to ground was at the distribution transformer, we also had to use a ground resistance meter to measure between the neutral and ground path back to the transformer GND in order to comply with the maximum GND resistance allowed.

I am not sure if it is any different now.
(When I left, conductors were still imperial dia)!
 
Nigel Goodwin said:
The water companies use a number of different methods for detecting and tracing pipes, and different methods work better in different cases, with plastic pipes been particularly difficult.
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I have two gas wells on my property, when they ran the pipes from the wells to my house, they were plastic. When they put the plastic pipe in they also buried a ~12Ga copper wire with the pipe so they can trace it at a later date if needed. The copper wire comes above ground at both ends, they told me they attach some sort of transmitter to the wire when tracing is needed.
 
MaxHeadRoom78 said:
I recall many decades ago, in the UK everyone that was connected to the local water facility had a metallic supply service.
This was used for the earth ground reference, once these were replaced with non-metallic supply, RCD's became mandatory.
Click to expand...
This makes me wonder, if you have a plastic (fiberglass) bath with PVC piping, will an electrical appliance dropped into the bath cause an RCD to trip? My guess is no, the water (and you, if in it) will just become part of the circuit, so how do they prevent this? I know, no plugs in bathrooms but here it's allowed. I'm wondering if there is some other way to ensure the water is earthed? Would having a tap running cause a path to ground and potentially save your life? I know stupid question but I'm curious.

Mike.
 
Pommie said:
the water (and you, if in it) will just become part of the circuit
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If you find yourself as part of the circuit between Live and a good Earth, won't that be worse than if the water were not well-earthed?
 
alec_t said:
If you find yourself as part of the circuit between Live and a good Earth, won't that be worse than if the water were not well-earthed?
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I'm saying that if the water isn't earthed then an RCD cannot detect any flow to earth and will not trip. If you find yourself between Live and a good Earth then the RCD will trip and protect you. Or, rather, that's my question, am I right?

Mike.
 
Pommie said:
This makes me wonder, if you have a plastic (fiberglass) bath with PVC piping, I know stupid question but I'm curious.

Mike.
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This was many decades ago in my youth in the UK, before I did my Electrical training.
Why does an isolated bath need to be earth grounded?
As I said, not sure if things have changed and UK allows the neutral to be bonded to earth GND in the panel, as it is in N.A.?
In my time in the UK, the inspector would refuse to pass an installation where the neutral contacted earth GND.
The only place this could occur was at the service transformer.
 

Have a google for PME earth, 'M' stands for multiple - so your old inspector wouldn't have been a happy man for the last few decades Apparently it's by far the most common earthing system in the UK?.

Funnily enough - I only noticed the other day (because I was looking at the wires), my house and the two to the right are all connected to the same phase, rather than the usual alternate phases.
 
Nigel Goodwin said:
Funnily enough - I only noticed the other day (because I was looking at the wires), my house and the two to the right are all connected to the same phase, rather than the usual alternate phases.
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What phases are you talking about?
I was accustomed to the normal UK residence wired with a phase and the star (earthed) neutral?
The exception was one residence that installed a off-peak storage heater in each room, the service Co. requested them to be wired over 3phase, for which they supplied the 3ph .

So now UK connects the neutral to the earth GND conductor in the panel?
 

The UK has long since (presumably since the implementation of the National Grid?) distributed power as three phase - at street level it comes out of a three phase transformer, and each house has a live and a common neutral connection. In order to balance the load (and allow them to use a cheaper thinner neutral cable) each alternate house is (normally) connected to a different live. So as you go down the street, L1, L2, L3, L1, L2 etc. - this keeps things nice and balanced.

I live in a 120 year old (or so) house, and the power is run along the front of the houses - I've lived here 40 years (and just over a week! ) and never noticed before that there's only two wires running across my house and the previous two. Mine is also the end of that run, and next door the other way has a feed out of the ground that then runs along the next run of houses (I'd never noticed that before either).

So now UK connects the neutral to the earth GND conductor in the panel?
Click to expand...

Possibly, looking at googles suggestions that's one option of PME - as far as I know I still just have an earth spike?.
 
The Alternate residential feeds were implemented as far back as I can remember.
The situation of the panel earth non-connected neutral existed until I left in '70.
It applied whether a GND rod was used or the water service pipe for Earth..
The bonding across all sink and bath water waste points also came into effect when I worked in that particular occupation.
That was back when the old wastes were lead piping, and an old pro-Plummer taught me how to wipe a joint.!
 
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