Remote operation of york chiller

[khumphreys]

I am trying to start and stop a york max-e centrifugal chiller remotely via a BMS. Wiring diagram shows terminals 1, 7 and 8 on the I/O board. The control source on the optiview display is currently showing local. All I am doing with the terminals on the I/O board is closing a set of contacts on my BMS and sening the signal back. This seams to be digital to me. My York tech is telling me Analog. The wiring diagram says the chiller must be in remote mode, but remote is not a choice. The choices are local, digital, analog, and YSN. I think it should be digital. What do you guys think? I would like to trust my service guy but his explaination just seems wrong.

[Cadrion]

Hi there...If I am not mistaken, you need to set the control source to digital, then close 1 and 7 (with 1 and 8 open) to start and clost 1 and 8 (with 1 and 7 open) to stop- a set of spdt contacts work great. In local mode, these contacts don't do anything- the chiller controls its self from internal schedule, or if that's not set, the black rocker switch. Which, by the way, the rocker has to be in the run position to use the digital mode. Basicly, it's "remote digital" and "remote analog." If it has an ISN setting for the control source, that was for some propietary stuff York had...not usre it's still around or not.

[york56]

Hi there...If I am not mistaken, you need to set the control source to digital, then close 1 and 7 (with 1 and 8 open) to start and clost 1 and 8 (with 1 and 7 open) to stop- a set of spdt contacts work great. In local mode, these contacts don't do anything- the chiller controls its self from internal schedule, or if that's not set, the black rocker switch. Which, by the way, the rocker has to be in the run position to use the digital mode. Basicly, it's "remote digital" and "remote analog." If it has an ISN setting for the control source, that was for some propietary stuff York had...not usre it's still around or not.

Sounds like we have a winner. I concur