I'm not technically an electrician but I am in the electrical and solar trades and I'm very familiar with residential commercial wiring and NEC code.
20 amp 12/2 sounds good for a 1.5hp pump motor. I have a different Hayward cartridge filter setup with the 1.5 horsepower motor. No SWG.
I actually downloaded the manual to your Solaxx Saltron product. The timer is built in, and there are terminals for 120VAC on power supply of the Saltron to wire the Saltron to your pool pump. Depending on where you live and what your local building and electrical codes are as well as your frost line in the winter if applicable, the PVC pipe will have to be buried a certain amount of feet depending on your frost line to prevent from cracking in winter, and backfilled. Here is another thing with the regard to the legalities of installing your own electric as a homeowner. Technically you are allowed to extend a circuit or make it into a branch circuit that is already existing without having to pull a electrical permit from the town. If you are creating a new circuit with a new breaker, new wire, new box and circuit, etc, it typically will require you to pull a permit and electrical inspection. Whether you want to do that is totally up to you. Another thing I'd like to mention just for the sake of load balancing your electrical panel, and reducing getting built too much from your utility, and your electrical panel you have two main feeds coming in typically from the meter pan in residential. Black L1 Red L2, N and Ground. If you think about what is installed on your service panel. For example you have your dishwasher on L1 side and your electric dryer on L2 side, your dishwasher is 20 amps and electric dryer is 40 amps. Once I will be running higher amperage depending on how your appliances are stacked on that side if you understand what I mean. When this happens with poor distribution of load balancing on a panel the electric company wines up billing you for Peak demand which results in higher electric bills then intended. So when you add that 20 amp 12 to Circuit that's new, just keep in mind the design and layout of electrical panel on which side to add it to result in Optimal Performance.
Try downloading the manual from this link. I have taken the electrical information and copy it into here from the manual below.
salthttps://solaxx.com/products/reliant.html
Important Safety Instructions
Read and Follow All Instructions
All electrical work must be performed by a licensed electrician and conform to all national, state, and
local codes. Improper use or installation can badly harm the unit and its surroundings.
When installing and using this electrical equipment, basic safety precautions should always be
followed, including the following:
DO NOT OPEN THE SEALED COVER OF THE BOX – NOT A SERVICEABLE UNIT
● Disconnect all AC power before installation.
● WARNING – To reduce the risk of injury, do not permit children to use this product.
● The Control Box must be mounted vertically on a flat surface and at a minimum horizontal
distance of 5 ft (1.5m) (or more, if local codes so require) from the pool/spa.
● WARNING – Risk of electric shock. Connect only to a grounding type circuit protected by a
ground-fault circuit-interrupter (GFCI) outlet. The installer should provide this GFCI requirement.
The GFCI should be rated for minimum 6 Amps and tested on a regular basis by pushing the test
button. If the GFCI fails to operate correctly, there is ground current flowing indicating the
possibility of electric shock. Do not use this unit.
Disconnect unit and have a qualified professional correct the problem before using.
● The Input circuit (LN1 & N/LN1) must be connected only after OVERCURRENT DEVICES, such
as fuse or circuit breaker to limit the amperage in the input wire to the maximum that is permitted
by the National Electrical Code.
● The Unit must be permanently connected, with copper wire, not less than 1.5 mm (14 Awg).
● The wiring of the unit must be performed according to the wiring instructions of this manual.
● A build-up of flammable fumes can result in a hazardous condition if the cell is allowed to operate
without flow. This device must be operated only with an approved inline flow sensor.
● The Flow Sensor must be installed between the last piece of apparatus and the Cell.
● Ensure that equipment and materials used in or around the pool and spa are compatible with salt-
based sanitation systems. Certain materials may be susceptible to salt and chlorine damage.
● ALWAYS ADD ACID TO WATER, NEVER WATER TO ACID.
● SAVE THESE INSTRUCTIONS.
1. The Power Supply Box must be mounted vertically on a flat surface and a minimum of 5 ft (1.5m)
horizontal distance (or more, if local codes require) from the pool/spa.
2. Locate a position for your Box within 8 ft of where the Cell will be installed and within 6 ft of the timer
box to ensure enough cable is available.
3. Because the box acts as a heat sink dispersing heat from inside the box, do not block the four sides
of the Control Box. Do Not mount the system above a heater or inside a panel or an enclosed area.
3.4 Wiring the Power Supply Box
Ground, L1,L2
Nor
Line
Timer
Pump
Power
Supply
Box
1. Connect the green wire to the Ground lug of the timer.
2. Connect the black Load wire from the chlorine generator to Load 1 of the time clock.
3. If wiring a 240 Volt system, connect the white wire with black shrink to Load 2 of the time clock. If wiring
a 120 Volt system, connect the white wire with black shrink to the Neutral lug on the timer and
REMOVE the black shrink tube.
120 VAC
CL
Power Supply
Green
Black / White
Black
Ground
Neutral Load 1
Remove Black
Heat Shrink
3.3 Install the Power Supply / Control Box
Power Supply Box
Mounting Configuration:
1
3 2
Screws and Anchor
Hardware Kit Included
240V Install 120V Install
3.5 Wiring the cell.
Connect the two black wires from the Power Supply Box to the two Quick-Connects on the sides of
the Cell. Ensure the connections are perfectly clean of any debris.
Note: these wires are interchangeable.
3.6 Wiring the Flow Sensor
Find the sensor cable from the Power Supply with the 4 small connect terminals and push them on
their respective connectors on the Flow and Temperature sensors. Polarity DOES NOT matter.
Hope this helps out with your question.