Switching OFF all the zones in HVAC

Hi,

I am having totally five zones in my HVAC (local zone, zone1, zone2, zone3 and zone4), and I am switching OFF all these zones one by one. After I switched OFF all zones then after when I am trying to switch ON any zones it is not switching ON.

Only when click power button ON and OFF then only I am able to switch ON the zones.

Can you please let me know, what is the problem with above scenario, is it expected behavior or something i need to take care in my logic.

Thanks & Regards,
Ravi Bukka

 

If you switch off all zones, then the air conditioner is probably being switched off automatically. If all zones are off there is nowhere for the air to go, so it is a self-protection mechanism.

 

Hi Darren,

Thanks for the reply, Is it expected behavior with HVAC running on CBus or it upto the client implementation.

Regards,
Ravi Bukka

 

I don't recall.

The easiest thing to do is to use the C-Bus Diagnostic Utility to see what messages are occurring on C-Bus and where they are coming from. Once you know which device is generating the messages you will be able to start working out what is happening.

 

Hi Ravi,

The airconditioner is switched off by the C-Bus thermostat once all the zones have been switched off.

The power button you are referring to indicates the status of the 'plant'. Once the plant is off the zones can no longer be switched on. As per the HVAC protocol, the plant must first be switched on, the unswitched zone will automatically be switched on by the thermostat, then any other zones can be switched on.

Regards,

Matty.