Can you turn on heater coil on at a timer?

Can you create a schedule to turn on the heater for set amount of time every X? The heater is controller by a Clipsal thermostat.

 

Use the schedule to define the turn on time(s) as usual, and the event 'pulse' option to turn it off after the required run time.

 

Thanks Ashley. Turned out a lot easier than I expected.

I created a schedule with a trigger group. The schedule is set to turn on the heater relay in the thermostat for 1 minute every 60 minutes. Since the minimum on time for the heater is 15 minutes, this will mean the heater is on for 15 off for 45. I then added a button to the wiser interface that enables the trigger group.

 

Ashley,

Looks like I spoke too soon. I tested out the enabling and schedule on a 1 minute interval with one of my lighting relays and it worked flawlessly. However, when I switched it to the thermostat group, it is not changing the state of the relay within the thermostat. Is there a way to control the state of the RL4 relay in the 5070THPR?

 

If the thermostat is set to control the heater relay (which I assume it is), you won't be able to control the relay directly because the thermostat will just override it. You need to turn the actual thermostat on and off. You didn't say which thermostat you are using but I assume it's the single zone one that doesn't support scheduling directly. In this case, create a pulse schedule in the "HVAC actuator 1" application (or whatever yours is called), and select the "heat/cool" group. This effectively pushes the on/off button on the thermostat.

 

I referenced the thermostat above but you might have missed it. It's a 5070THPR.

I connected via the cbus toolkit and turned on the thermostat. This is what the log showed:

Code:

DateTime= 10/6/2014 10:10:56 PM     App= 172  Air Conditioning     Group= 001  HVAC Communication Group Unit= 006                       Event= Communication Group on
DateTime= 10/6/2014 10:10:56 PM     App= 172  Air Conditioning     Group= 001  HVAC Communication Group Unit= 006                       Event= HVAC operating type: Zones = Unswitched; Plant equipment = Heat pump - reverse cycle; Mode = Heat; Flags = Temperature unit is ?C, Setback disabled, Guard disabled; Set Point = 20.0?C; Automatic Fan Mode; Fan running at default speed 
DateTime= 10/6/2014 10:11:01 PM     App= 115  HVAC Thermostat 1    Group= 001  [CG01] Y (heat/cool) Unit= 006                       Event= Group off
DateTime= 10/6/2014 10:11:01 PM     App= 172  Air Conditioning     Group= 001  HVAC Communication Group Unit= 006                       Event= HVAC plant status: Zones = Unswitched; Plant equipment = Heat pump - reverse cycle; Flags = Damper open; No error

None of the HVAC groups switched to ON to signify that the thermostat is turned on. I then added an activation group, [CG01] B (heat activation) - 004, but it only works in one direction. Meaning, the thermostat does not read or care if it is on or off, it will just write the current state of the thermostat being on or off and not read from it. The house is old and the forced air heater only has two wires that have to be closed for it to work, basically like an on-off switch.

So, how can I control the thermostat being on or off?




On a side note, the localization is broken as I have it selected to be Fahrenheit both on the thermostat in cbus and metric units are unchecked in the piced project details.

 

Oops, sorry, brain fade I got the bit right about not being able to control the relays directly as the thermostat will just override it (as you found out). My schedule just selected the wrong details.

You need to enable scheduling in the thermostat and create an 'override thermostat scheduling' group address, then create all the levels (you should only get an Off and Unswitched). Then in the schedule select the 'enable control' application, 'override thermostat scheduling' ga, and then select the unswitched zone. This should turn on that zone for the specified pulse duration. I haven't done it this way for a while, but that's the theory anyway.

If you have a logic device, you can also turn the thermostat on and off directly using the setSystemIO function on the 'HVAC Set Zone Group State'. I actually do it this way as I have found it to be easier to set up.

I can't shed any light on the units problem as I've only ever used them in degC but I know others have them working in degF so it can be done