Trane LciDac Issue

[EMPadvocate]

I installed a Trane Lci Discharge Air Control for ReliaTel card on a 50T Voyager VAVw/VSD on supply fan unit with low temp heat option and I can't find the right way to put the unit in heat. effective DASP tracks correctly with 7.5 degreeF error from DAT; econ and cool output go to zero but still no heating output. Heat works in test mode. Using JACE for lon.. What is magic sequence for this? SW1 on RTAM module is set as follows sw1- on; sw2- on; sw3-off; sw4-on; sw5-on;
Thanks in advance..

[willf650]

The unit goes into heat based upon space temp. Morning warmup is allways enabled and is activated on the change of occupancy state but daytime warm up is enabled via one of the dip switches on the board. Last time I looked it was clearly labled as to which one on the board. The unit goes into heat or warm up based upon space temp. If you leave the the unit heat/cool and applic mode in auto it should go in and out of heat based upon space temp but it needs to have a sensor wired to it. If you want "trick" the unit to go into warmup or "heat mode" so you can determine when it happens you can write a program to raise and lower the NVI space temp to make the unit go in and out of warmup artificially.

Those units are supposed to run in CV mode when they go into warmup so your supposed to drive the VAV to maxium air flow.

[summit-dude]

You need to denumerate the right value to change the mode of the AHU. Dac profile for us is 1 for heat mode 3 for cool mode. bind this to NVI applic mode

[willf650]

You need to denumerate the right value to change the mode of the AHU. Dac profile for us is 1 for heat mode 3 for cool mode. bind this to NVI applic mode

I'm fairly certain you are mistaken here. You can send it to heat via the applic mode but the burner still won't fire unless the space temp is low enough to enter the warmup. If the applic mode is in heat and the temp isn't low enough the fan will run but the burner still won't fire and the cooling will be locked out.

[EMPadvocate]

I solved the issue by taking Willf650's advice and wrote a value of the average space temp to nviSpaceTemp and setting occupied space temp setpoints. Writing nviAplicMode would not trigger the heat. Possibly might have to add more process control to the VAV boxes but I am going to watch it. It would've been nice to enable the heat on discharge setpoint bias using a nci for OSA heat disable or some thing like that, this being a VAV DAC unit.. :)

[willf650]

If they would have bought an Intelipac with a modulating burner they could have done that. You get what you pay for.

[summit-dude]

in the trane world we use an application that acts like a server between boxes and airhandler member probably right about applic mode w/o modulating heat wasn't thinking about that warmup sux though if you do it the way we do hope you have reheat in your boxes.