EXV forced closure?
I recently noticed that my air handler / indoor coil has a pair
of dry-contact input terminals to force its EXV to CLOSED during
When/why would you want to do this, and/or why would such a
function want to be able to be externally automated? I can't
imagine how it could be good for the rest of the system.
What indicates that this is what the set of dry contacts are for? Dry contacts are often for alarm triggering purposes.
- Electricity makes refrigeration happen.
- Refrigeration makes the HVAC psychrometric process happen.
- HVAC pyschrometrics is what makes indoor human comfort happen...IF the ducts AND the building envelope cooperate.
A building is NOT beautiful unless it is also comfortable.
Hobbit it this on your Daikin system we have talked about before?
Yup, the Daikin FTQ type air handler. Quoting from the
install manual description for option block terminals 9,10:
"Receives input: Forced closure of indoor unit Electronic
Expansion Valve during cooling operation. (dry contact)"
Seems like a strange thing to want an input for. Note: this
isn't the same as "forced off" that you'd use for safety
switches, condensate-pump overflows, etc.
Sorries did not notice this was in the ask a pro section.
Last edited by Elfshadow; 09-10-2012 at 02:42 PM.
Reason: was in wrong section.