24 VAC from Controller to PSR

I am running a GEN 2 Controller. My Well Pump is not coming on. I checked voltage at the Controller (M and C, M sends 24 VAC to Pump PSR) and found the correct voltage; however, the 24 VAC connections at the PSR are 8.5 volts totaling 17 Volts. The PSR is not switching on to connect the Power IN/Power Out to the required 115 VAC to start the 1.5 hp Pump. There is no voltage showing on the Power Out from the PSR but is present on Power IN. Should there be 24 VAC appearing at the PSR since it appears at the controller? Thank you for any guidance?

Most likely you are using a contactor (wiki) instead of a simple relay sufficient to run a 1.5 hp pump. Issue with those is that they require much more than 24VA power budget which is available to your Rachio controller. If you can find a model number of your start relay, we can verify the current requirements.

Newer PSR relays feature a secondary low power 24V relay which, in turn, drives the contractor off of line voltage. These models have a specific 110v or 220v rating. The version without the secondary relay has universal 110/220V rating, but requires a lot of power from 24v line.

Does yours look like A:

or B:

Most likely you’ll have to replace the start relay with something like this Orbit model (HD link) which should be well suited for 1.5 HP pump that you have.