Autumn/Winter November and onwards 2017 deployment(s)

[TerryJC]

Merry Christmas One and All

[hamishmb]

^ I'll second that

Hope you all are having a good Christmas, and happy new year!

Hamish

[Penri]

Hello Everyone

Please find attached a photo of the waterwheel shoot Hamish and I finished yesterday. The mortar's surface was a little soft this morning but the overall shape and finish looks nice, and hopefully will harden over the coming days. As yet there are no "permanent" fixings for the water-wheel axle or the shoot's head race/dam. I'd also appreciate ideas / help in smartening up the sump area so we can showcase what we've got there.



Hwyl

Penri

[Penri]

Hello

A couple of things:
I pumped the water out of the sump into the bog this morning a) to take a look at the floor of the sump b) to see if the circulation system still worked and c) to make some room so we can drain some water out of the river to re-install the filter baskets properly. Everything went fine, I stopped the pump and re-closed the bog stop-cock at the end of the operation.

I was taking to the electrician (Rev) this morning, he commented that Karcher type pumps (the butts pump) should not be left submerged for prolonged periods as they are prone to leak water into their electrics and trip RCDs, a day or two was ok but no longer. With this in mind I talked to Stuart and suggested that we change the one we have for a purpose designed pond pump (like the circulation pump), he agreed. So we're now in the market for two new pumps, one as a butts pump the other to route water to and from the butts farm. One would be submerged the other on dry land. I'm going to investigate whether the current circulation pump can be used non-submerged and get some costings.
So opinions please, should be try to make all pumps identical ie variable speed DC jobbyies / expensive ones, if they work out of water?

Hwyl

Penri

[hamishmb]

Okay, I guess that's why the power was tripping o_0

Not sure - each Pi only has 1 hardware PWM pin. We can do software PWM, or (probably, not checked) get a add-on board for more PWM pins, but that would be even more expense. The question is, do they *need* to be variable speed/would it be helpful? A pump that uses less power than the Karcher one would be good though - I remember it being a bit of a power hog, given its spec.

What do you think?

Hamish

[TerryJC]

Penri,

I agree with Hamish. If we use the PWM pin for the re-circulation pump and SSR switches for the other (dryland) pumps, I'm sure that would be good enough.

[hamishmb]

Fair enough. I'm sure PWM would have it's uses, like holding water while we open the gates perhaps, so I don't want to burst your bubble too much Penri Mostly, I'm just concerned about expense and not making life more difficult

Hamish

[TerryJC]

On the other hand...

If we have multiple Pis, ie one at the Sump and another at the Butts, we have multiple PWM pins, so we could still do linear control of the pumps if we want to.

I still think bang-bang control of the butts water is sufficient though.

[hamishmb]

Linear? I agree that non-PWM is fine though.

[TerryJC]

Linear in the sense of 30, 40, 50% etc as opposed to on-off. The water flow might not be controlled linearly, but the input to the motor will.