Thermostat monitoring

[RobWalker]

I am looking for advice on how to integrate my heating system with an Elk M1.

There are 12 heat only zones in total (seemed like a good idea at the time...) that each have their own 24VAC thermostat. Currently they are a mix of programmable and plain old thermostats.

I want to hook these up via the Elk so that I can detect which thermostats are calling for heat and (independently) control which zones are turned on. All of the thermostat wiring was homerun to the wiring closet, and then on to the heaters.

I was planning on doing this using relays on both the input and output side. 12 relays hooked up to an input zone expander to detect the thermostat state, and 12 hooked up to an output zone expander to control the heaters.

The Elk rules would normally allow simple pass through, but I want to also be able to pre-heat during off-peak period and prevent the heaters turning on during the peak rate periods. This logic can be off loaded to CQC without any problem, my main question is on the hardware side. Do I need 24 relays to achieve this or is there a simpler way? I assume I can't plug a 24VAC thermostat directly into an Elk zone input.

 

[will40]

I am looking for advice on how to integrate my heating system with an Elk M1.

There are 12 heat only zones in total (seemed like a good idea at the time...) that each have their own 24VAC thermostat. Currently they are a mix of programmable and plain old thermostats.

I want to hook these up via the Elk so that I can detect which thermostats are calling for heat and (independently) control which zones are turned on. All of the thermostat wiring was homerun to the wiring closet, and then on to the heaters.

I was planning on doing this using relays on both the input and output side. 12 relays hooked up to an input zone expander to detect the thermostat state, and 12 hooked up to an output zone expander to control the heaters.

The Elk rules would normally allow simple pass through, but I want to also be able to pre-heat during off-peak period and prevent the heaters turning on during the peak rate periods. This logic can be off loaded to CQC without any problem, my main question is on the hardware side. Do I need 24 relays to achieve this or is there a simpler way? I assume I can't plug a 24VAC thermostat directly into an Elk zone input.

Rob,

That is alot of zones. What are you using now for a control panel? Does each zone have a circulator pump or do you use electric modulator valves?

Sounds like what you have in mind is the most cost effective solution. The input and output relays would be low coil current. It is easy enough to build your own control panel prewired to terminal strips for inputs and outputs.

No you cannot attach 24VAC to an ELK input.

Will

 

[RobWalker]

That is alot of zones. What are you using now for a control panel? Does each zone have a circulator pump or do you use electric modulator valves?

Yeah, it is a lot ... in retrospect probably too many. There are 3 distinct systems: 2 electric Legalett heaters downstairs that are responsible for heating the ground floor slab, one with 4 zones and one with 3. Upstairs there is a hydronic baseboard system with 5 zones and a single circulator pump with valves for each zone. That system has its own simple control board for hooking up the thermostats and the pumps/valves. I don't want to mess with that, just inject the Elk into the system as effectively set of a 'virtual' thermostats.

Sounds like what you have in mind is the most cost effective solution. The input and output relays would be low coil current. It is easy enough to build your own control panel prewired to terminal strips for inputs and outputs.

Yes, the output side seems straight forward - I can just use standard Elk relay modules on the outputs to control the heaters.

No you cannot attach 24VAC to an ELK input.

Pity ... that would make it a lot easier I couldn't find a pre-built low-cost board for this, or even a simple relay that would trigger on 24VAC.

So this boils down to: what is the cheapest way to hook a 24VAC signal into an Elk input zone?

 

[will40]

That is alot of zones. What are you using now for a control panel? Does each zone have a circulator pump or do you use electric modulator valves?

Yeah, it is a lot ... in retrospect probably too many. There are 3 distinct systems: 2 electric Legalett heaters downstairs that are responsible for heating the ground floor slab, one with 4 zones and one with 3. Upstairs there is a hydronic baseboard system with 5 zones and a single circulator pump with valves for each zone. That system has its own simple control board for hooking up the thermostats and the pumps/valves. I don't want to mess with that, just inject the Elk into the system as effectively set of a 'virtual' thermostats.

Sounds like what you have in mind is the most cost effective solution. The input and output relays would be low coil current. It is easy enough to build your own control panel prewired to terminal strips for inputs and outputs.

Yes, the output side seems straight forward - I can just use standard Elk relay modules on the outputs to control the heaters.

No you cannot attach 24VAC to an ELK input.

Pity ... that would make it a lot easier I couldn't find a pre-built low-cost board for this, or even a simple relay that would trigger on 24VAC.

So this boils down to: what is the cheapest way to hook a 24VAC signal into an Elk input zone?

My guess is the relays are the way to go and your time assembling in a cabinet. A 24VAC mini relay with base is going to run you between $13 to $20 each. The AC puts you in the HVAC market and they are not cheap.

I use RIB's for everything I am switching in my house for ELK inputs and other controls. They seem to be most dependable , 42ma coil draw, and 10A contact. RIBH1C is the model made by Functional Devices. I paid $16 each.

Maybe you can get a bulk deal on Ebay.

Good luck.