Hey, it got really warm and humid here in SE PA, and my upstairs got quite warm....84F.  Decided to try the a/c for the first time with this new Geo Max 2.  If you've read my other posts, you'll know the system has some...kinks....to work out.

I set the thermostat to 74 F and turned on the air. 

First thing I noticed was really cold air!  Lovely!  Measured it at 50 F from the duct.

However, now I notice that on the zoning panel, the Cool 2 LED is blinking.  The manual for the Honeywell HZ432 Zoning Panel says "Blinking - Cooling Stage 2 lockout due to DATS" but that's all it says.

I'm assuming "lockout" is not a good thing.  I had heating stage lockouts due to low EWT.  The DATS is the duct temperature sensor right in the main trunk. 

Does this mean...
The zone is not cooling fast enough?
The duct temperature is still too high/low?

The HZ432 manual is pretty useless as to what causes a cooling lockout.  Any thoughts?

I'm not an expert in this one, but I think this lockout is done by the panel to protect the heatpump. If the HZ432 Zoning panel is locking out stage 2, it is because the zone you are cooling only requires stage 1 to run. Since you have a zoned system and reduced airflow is sent to the zone calling for cooling, if stage 2 cooling were to kick in, the DATS would read even lower. The HZ432 is designed to monitor discharge temperature that could cause the unit to ice up your coil, causing no air to circulate and the heat pump would go into it's own lockout. The stage 2 cooling lockout is a different kind of lockout than your low EWT that happened on the unit. The low EWT lockout sounds like it was internal to the unit that was actually a low pressure lockout due to low loop temperatures.

Hopefully that clarifies things a little. Sounds like the HZ432 is doing what it is suppose to do, based on the HZ432 manual. - Just a drillers thoughts, some other can chime in and correct me if I'm wrong.
Dan

DATS is discharge air temperature sensor. If you had 50 at a register the air at the coil was likely in the 40s. I wouldn't expect such a low DA temp with ambient at 84 - I suspect very low airflow. Normal 'split' (cooling delta-T) is 17-21 degrees, in other words, with the system getting return air at room ambient it would supply air at 63-67 degrees, not 50.

A coil discharging air in the 40s is in danger of icing up, so it makes sense for the zone board to lock out stage 2 while the coil is so cold.

I got to a Honeywell install guide (60-2070-01.pdf) for the HZ432 pretty quickly by Googling HZ432. All the ins and outs of DATS are therein explained.

Air temp too low. Check filter, E an L air temps and sensor.
Joe

I guess the too-little-air-flow could be as a result of the 10x10 duct that feeds the zone that was on when this happened. 10x10 seems awful small for a whole zone supply.

engineer - I have the HZ install guide...a paper one, too, from when the system was put in. I can't for the life of me find where it talks about the DAT being too low as the cause.

However, that makes sense re the air flow and resulting temp drop of the coil. I know the system is protecting itself (like the heating lockout when the EWT was too low), but in this case, it's due to reduced air flow, probably to the 2nd zone that's fed by that single 10x10 duct I've posted about. The upstairs did get down to temperature, but IMHO, it should have happened much faster. Gotta get a duct guy in to check the supply and return sizes.

That's right. I'd forgotten your poorly designed duct system.
Fix the ducts and the lock out will go away.
j