On/Off Pump Control

[hamishmb]

Okay. Will that software need to be integrated with our framework? I thought it might be a hardware thing so I didn't plan for that eventuality!

[Penri]

Hello

Hamish installed the SSR in its box behind the shop front this morning, connecting it to the four way trailing socket and the pump.

Penri

[Penri]

Hello

Please find attached a proposed revised SSR circuit to allow us to ON/OFF control two pumps.

You will note that I've used the same 4 way connector as for the single SSR circuit but redefined Pin 4 (the Green wire) from 0V to SSR 2 Control Hi.
SSR 1 will control the Sump to Wendy Street butts pump, SSR 2 will provide ON/OFF control for the River System circulation pump.

Hopefully this will mean minimum re-configuration is required in the Sump Control Box.

If you are OK with the circuitry proposed. I will get on with building a new twin SSR box and keep the existing single SSR one until we install the new pump that will drive water to and from the other butts farms, then we will have that one available to control it.


Hwyl

Penri

[TerryJC]

Seems OK and we can use the second channel on the Wendy Street Interfaces Board (Pin 43) to drive the second SSR.

[TerryJC]

Oops! I should have said the Sump Interfaces Board.

[hamishmb]

Looks simple enough to me.

[Penri]

Hello

Please find attached a simplified circuit for Pump ON/OFF control.



Hwyl

Penri

[Penri]

Hello

Photos of finished Twin SSR box attached. Tested with 8W low energy bulb to make sure it could switch small loads, worked as expected.

Will bring along on Tuesday.

We can install when mods have been made to the Sump Control box wiring and the software is ready.

Just to recap the additional SSR is there to control the circulation pump to prevent it running dry when the sump level is low. Currently when the sump level is too low and the circulation pump is switched off the sump re-fills from the river system head and eventually flood down the soak-away unless someone is there to switch the pump back on.

On the S/W front I was thinking that the circulation pump should switch off if the sump level drops below 300mm and back on when the water level goes above 400mm. This will mean that we have another sensor above (500mm) and below (200mm) each level should the 300mm and 400mm sensors go AWOL.

Factors in suggesting these levels
I've never seen 100mm come up in our sump recordings, please correct if I'm wrongs with this one.
I wanted to make sure the butts pump didn't come on to during this low water condition, hence choosing 400mm.

Happy to discuss alternatives.

BTW I haven't assigned which SSR is which but to be consistent with the single SSR circuit the Yellow wire on Pin 3 of the connector now controls SSR1. Plugging the Twin SSR box into an unmodified Sump Control box should not cause any damage.


Hwyl

Penri

[TerryJC]

We can install when mods have been made to the Sump Control box wiring and the software is ready.

BTW I haven't assigned which SSR is which but to be consistent with the single SSR circuit the Yellow wire on Pin 3 of the connector now controls SSR1. Plugging the Twin SSR box into an unmodified Sump Control box should not cause any damage.

The current SSR is switched by GPIO Pin 5 and routed from the Interfaces Board on Pin 41 (Return Pin 42). In order to work, we had to provide the driver circuit on the Interfaces Board with a 19 V rail because the only other available voltage (5 V) failed to reliably switch the SSR.

The second SSR can utilise the second driver circuit on the Interfaces Board which is switched by GPIO Pin 18. This channel was originally intended to drive the PWM Motor Control Board and the driver circuit has a 5 V rail to suit the PWM Board. To make this work therefore there will be four modifications needed to the Interface Board:

• Remove the link from Vcc of the driver to the +5 V rail.
• Add a link from Vcc of the driver to the +19 V rail.
• Add a wire from Pin 44 of the Interfaces Board to a spare pin of the Round Industrial connector.
• Add a another wire from Pin 45 of the Interfaces Board to another spare pin of the Round Industrial connector.

The first two items will require access to the underside of the Veroboard to be done properly. We could bodge it by snipping the redundant link and tacking the new one between Interfaces Board Pin 37a, b or c and the top of the 10 k resistor in the drive circuit.

The second two items presuppose that we have two spare pins on the Round Industrial connector. Again we could bodge it if we had one spare pin by commoning up the return lines inside the SSR Box.

Hamish,

Your software will therefore need to support the algorithm outline by Penri (or whatever else we decide) and then toggle GPIO Pin 18.

[Penri]

Terry

The round connector has only 4 pins (all used): +ve Supply, 0V, SSR1 control & SSR2 control.


Penri