@shagymoe
1. You are correct. With a pool and spa AND provided that you will not require more than 4 AUX Circuits, you will require an IntelliCenter i5PS.
2. Next, in order to determine which model # or "kit" that you need, you will have to determine if you want an IntelliChlor salt system bundled with it (it's recommended).
3. The model #
without an IntelliChlor is:
521907, IntelliCenter System Load Center i5PS. Includes Load Center and two IntelliValves (also recommended).
4. The model # with an IntelliChlor is:
521906, IntelliCenter System Load Center i5PS, IC40. Includes Load Center, IC40 and two IntelliValves.
To answer your questions regarding the main board (mothercard) and personality or "daughter" cards, here we go.
1. Every IntelliCenter comes minimum with the i5P mothercard. Period. This is all one would need if they just had a pool only (one body of water) AND do NOT require more than 4 AUX Circuits (Power Relays).
2. Those with a
pool AND spa (such as yourself), will need a daughter card to go along with the mothercard. The daughter card provides two capabilities. The first is that it allows valve switching from pool to spa for both Intake (suction) and return. The other is that it
MAY allow for additional AUX Circuits depending on which daughter card is required..
The
i5PS daughter card allows for body of water (pool/spa) switching but has NO additional AUX Circuits.
The
i8PS daughter card allows for body of water (pool/spa) switching and has 3 additional AUX Circuits.
The
i10PS daughter card allows for body of water (pool/spa) switching and has 5 additional AUX Circuits.
3. So, you see that the reason there are valve plugs for Intake and Return on the daughter cards is those are designed for folks with two bodies of water (pool/spa). The reason those valve plugs are not on the i5P mothercard is because the i5P mothercard by itself (without a daughter card) is for those folks with just one body of water (pool)
only.
4. So like I said in the beginning, because you have a pool AND spa and if you DO NOT have a need for more than 4 additional AUX Circuits (power relays), then you will need the i5PS - which will come with the mother card (i5P) and the daughter card (i5PS).
i5P mother card - All IntelliCenter's have this card. This is all one would need if they only had one body of water (pool) only.
i5PS daughter card - Notice on this card that there are no additional AUX circuits but does allow for two bodies of water (pool AND spa).
i10PS daughter card - The difference here is that the i10PS daughter card has 5 additional AUX Circuits.
I hope this helps to clarify all this a bit for you..
You can find this information along with other additional IntelliCenter information here -
IntelliCenter Quick Reference/Information Guide
r.