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1) The sub-panel feeder circuit requires a 4 wire circuit comprised of 2 hots, 1 neutral and 1 equipment grounding conductor. Yes, 4/0 aluminum conductors are required and will result in a 1.8% voltage drop or a loss of 4.4 volts. National Electrical Code recommends the voltage drop be 3% or less. Therefore, the 4/0 aluminum is OK. If installing the feeder circuit in PVC conduit, the equipment grounding conductor needs to be sized as a minimum of 4 AWG aluminum.
2) All 4 sub-panel feeder conductors can fit inside (1) one 2" diameter gray electrical PVC Schedule 40 conduit. Although to make the wire pull easier, I recommend to increase the conduit to either 2 1/2" or 3" diameter. Bury the sub-panel feeder conduit run a minimum of 24" below final grade.
At the sub-panel, you will need a quantity of (2) two 8 foot ground rods spaced a minimum of 6 feet apart. The grounding electrode conductors at the rods needs to be sized as 4 AWG copper.
3) A 240 volt single phase motor that is 1 1/2 hp has a full load current of 10 amps. Due to the "in-rush" current, the minimum breaker size is sized at 125% of the FLA rating. Therefore, 1.25 x 10 amps = 12.5 amps. Round up to the next available trade size breaker and use a 15 amp double pole breaker for the well pump.
4) The 230 foot well pump run requires 8 AWG copper for the 2 hots and (1) one 10 AWG copper for the equipment grounding conductor. If using PVC conduit for the well pump, minimal diameter pipe is 1/2". In order to make the wire pull easier, I recommend to install 1" conduit. The voltage drop on 240 volts/15 amps on a 230 foot run results in 2.2% voltage drop or a loss of 5.2 volts which is code compliant and therefore OK.
5) Since the 200 amp sub-panel will be installed outdoors and exposed to the elements, it needs to be rated as a minimum of a NEMA 3R (waterproof type) panel. Install a 200 amp sub-panel that has a 200 amp main breaker and not a main lug type of panel.
6) All feeder and branch circuit conductors need to be rated as type "THW" for wet conditions.
7) Install a warning ribbon tape directly above the sub-panel feeder trench and the well pump trench. Bury the warning ribbon tape approximately 6" below final grade level on the entire conduit/trench run to provide a warning that anybody digging and/or trenching in the future that an electrical line exists directly below.
8) At the sub-panel, DO NOT install the green main bonding screw or a main bonding jumper strap. On all sub-panels, the neutral must remain isolated from the panel metal enclosure., By not installing the main bonding jumper is how the neutral remains isolated. At the sub-panel, you will need to install a separate equipment ground bar for the equipment grounding and grounding electrode conductors. DO NOT inter-mix white neutrals and grounds on the neutral bus bar. Neutrals only land on the neutral bus bar and grounds only land on the equipment ground bar in a sub-panel.
9) Identify both conduit runs by pounding either metal stakes in the ground and spray painting them with a red color and/or reference the conduit run dimensions from corners of the building and/or power pole structures and/or the property easement/boundary lines. Document both conduit runs with the appropriate dimensions for future reference and create an "as-built" drawing in the event future digging near these areas need to occur. Make a copy of the "as-builts" and tape them inside the respective electrical panels for future reference.
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