Not if they are: "... set-up to purge with power on & every 30 mins.":
Ok I will split hairs with you, sounds like a fun game. A purge every 30 min is a waste of energy/air, increases run time. Whereas a pneumatic trigger only dumps as the compressor cycles, logic tells me that is a better approach.
:[/QUOTE];The biggest problem with the harbor freight model is -- it is Harbor Freight.

[/QUOTE]
No argument we agree, but I did figure out a way to make it operate. The reason I did that is because the pneumatic trigger is a better process without the need of an additional outlet. Does not have a timer, dumps only when required.
Lets just face it, unless the compressor is operating there is no need for dumping the moisture is there ? Last time I checked no clouds are being sucked into the tank and raining every so often.
My compressor stays on 365 and the pneumatic triggered drain is exactly what fits the bill.
That was fun,
Pepi