[USA] Wiring Pool Equipment properly with a timer

[Fried Chicken]

Currently in the process of re-plumbing and upgrading the equipment on a pool.

I've successfully wired a 2-speed 240VAC Century B2983 pool motor controlled by an Intermatic P1353ME pool timer via a GFCI 20A circuit breaker sufficient for all the devices.  This could possibly be an improper way to wire everything, see last paragraph.


The challenge: I have a Sta-Rite SR 333 NA pool heater (interchangeably configurable for 120v or 240v - presently configured for 240v) that should only be able to be turned on if the pool pump is running on high.  It shares the same common (120v hot) as the pool pump, however I am not sure if I can safely/correctly/appropriately attach the other 120v leg using the same switched circuit.  A diagram explains this better than words:



Figured out the issue while writing this post.  The issue is: a ground fault in the heater (on the non-common side) wouldn't trip the 20A breaker, b/c the pump motor would limit the current through that ground fault to 20A.

So the challenge persists.  Per the Sta-Rite Heater manual, bullet point 6:



So I still need to figure out a way to have the heater disconnect with the pool pump to prevent the undesirable scenario of the heater running while the pool pump is off.



Finally; the timer that I'm using has a wiring diagram with my intended use case: a 2-speed pool pump motor and an auxiliary pump (in my case a chlorinator pump).



The diagram specifically emphasizes three separate breakers: one for the timer, one for the filter pump, and one for the auxiliary device.  I'm going to call them tomorrow, b/c I don't see why I would need three separate breakers.  When I spoke with them on the phone, I think they said I could jump terminals 1, 3, and 5 (I didn't discuss 7).  I'm too exhausted to think about this in depth right now, and hopefully my questions still make sense.  Any help is much appreciated.  Figuring out the insidious heater circuit error from above has me questioning everything.

[themadhippy]

So I still need to figure out a way to have the heater disconnect with the pool pump to prevent the undesirable scenario of the heater running while the pool pump is off.

relay/contactor with the coil powered from the pump circuit and the switch contacts controlling the heater?

[Fried Chicken]

So I still need to figure out a way to have the heater disconnect with the pool pump to prevent the undesirable scenario of the heater running while the pool pump is off.

relay/contactor with the coil powered from the pump circuit and the switch contacts controlling the heater?

I thought to do this too, and it turns out that's a common use for these relays.  How to mount it?  DIN rail box that also holds the timer?

[Fried Chicken]

Pool heaters, and my pool timer, have a "Fireman's Switch" - communication device that turns the pump on when the heater is turned on.

Problem solved.