climate changer w vfd no controler/board

[markm0369]

ok heres the drill guys just put in a dx4 climate changer intertwined coils in the celing,w condensors on the roof. had 2 problems 1 no board or controler (ah540/541)ordered with ahu, any way to make a standard 24v ac multi stage thermostat feed signals to the vfd (would like 2 speeds out of it at least) can probably do it w a couple of relays and and the vfd dc output but hate to get real creative with a new system just yet. and 2, the old piping was semi hermatic 10t w 7/8 liquid line. we reused this for 2 of the 4 circuits, will this subcool too low or still ok, 60-70 ft lineset. new lineset 1/2 X1 3/8 thanks

[ralphtheplumber]

What kind of vfd?

Usually there's a couple contacts for preset speeds. Set those up in the vfd menu, and wire those terminals to a couple ice cubes off your stat or compressors.

It'll probably work 'til your board shows up. You might have to fiddle with it.

[markm0369]

I think its danfoss, what ever the optional accessory mfg for the trane climate changer. just hate to rig it dont think the company is gonna buy the board, may just wire it up like a standard full speed ah

[ralphtheplumber]

Hold on a minute..

shouldn't you be running the vfd off a duct pressure sensor?