Hello, I have a 4ton tz (TZV048AGD06NRTS) with open loop using a modulating valve. Recently, I have configured the valve in fixed% rater then delta T because we had too many problems. Now it works fine except when the machine starts. The compressor will start at the same time the valve starts to open. It takes some time to the valve to get to the 65% openeing so the LT1 has time to drop because the compressor runs wihtout water for 40 seconds or so.... Often, if the water is colder because not moving, we will get an LT1. Before, in delta T mode, the valve would start to open before the comrpessor starts so the LT1 would not drop like that. Is there a way to configure the machine so that in fixed% mode, the valve starts to open before the compressor starts? Cheers, Laurence.
Typically, on valves, you want the valve to intercept the thermostat call (typically the Y) and only pass it through (using the end switch) when the valve is fully open. Now that's just sort of an industry standard. How individual manufacturer's are now recommending you wire valves to their boards can (and does) vary. I'm not a CM expert, and I'm hoping somebody else can chime in without having to pull up the wiring schematics myself.
Thanks utrhbuoy, I completely agree with you. This is what I would like to do. The valve comes built in the machine, so I'm not using the auxilary outputs to control it. With the auxilary outputs, yes you can use all kind of triggers and that's nice but can I do such thing with the CM valve? Anyone with experience with CM?
