Hoping someone can spot something simple.
I have 2 pumps, that I never want to operate at the same time.
In the link I have attached a drawing of my thoughts …
Condition 1. Programmer in Timed=OFF
No live to Heating Ctl board, and no power to pump BP. If flow switch
operates, then RLY (after time T) will operate and put power onto pump
SP via connection (2b) … all fine
Condition 2. Programmer in Timed=ON
Provides live to heating controller … and in the event of it calling for
heat will provide a switched live feed from ‘pump ’ and I can use that
to power the boiler pump BP, via RLY connection (1a)
There are a number of thermostats, zone valves etc. all under control of
Heating Control board so can only run pump BP when there is a 'Pump'
If the flow switch operates when boiler is making a heat call, I need
pump SP not to operate, as there would be no power to (2b) that
requirement is met
The issue I have is if there is no call for heat and flow switch
operates I need pump SP to run … so I need to get live feed to it at
that point ……… currently stumped.
Am I missing something that I can achieve given the DPDT contacts in
relay and SPDT in the programmer.
Otherwise I will have to add in another RLY