Changeover of Wall Mounted Air Conditioner

[weeliang82]

Dear all,

I need to do a changeover for 2 units of wall mounted air conditioner in a server room, each one running 12 hours. I would like to know how it can be done..

Can anyone advice?

Wer can I find out how the wiring can be done..?

Thanks...

[james10]

most models can be set using a timer operation within the controller.

[chemi-cool]

Two contactors and one timer that changes between them at set time or hours.

On the other hand, why do you need to change over every 12 hours?

It doe's not make any sense.
If you want, I can make you electric diagram.
Is the supply 220V or 400V?

[weeliang82]

Chemical Cool: The reason I want to change over every 12 hours is because I'm installing it in server room, and it does not make any sense to let one unit running 24hours/7 days a week (server room running with air conditioning 24 hours a day)

What I want to know is that what is the tools or equipment that can be used to connect these 2 air conditioners that automatically runs and stops when the time comes. I believed it is known as interlock timer and the question is, how do this equipment work? And how we connect it to our air conditioner?

[Brian_UK]

You still need to tell us what make and model is the equipment.

Without this we are helpless.

[frosty74]

i have done it before using a refrigeration controller ie carell also linked up the controller to alarm as this monitored room temp also.

[El Padre]

Mitsubishi Electric can supply you with a changeover panel ( Procon RMS ) for their equipment, by default it changes duty unit weekly and provides remote alarm indication, can send a text message of the fault etc.

As has been mentioned, what manufacturer are you referring to ?

Ciao

[Makeit go Right]

I need to do a changeover for 2 units of wall mounted air conditioner in a server room, each one running 12 hours.

Timers and contactors, switching aircon units is a bit of unnecessary complication, I would say. :confused:

Why not set the room stats so the standby unit runs at 1-2 degrees above the lead. Every month, change it over so the other is leading. Keep it simple, kind of thing.

Every 12 hours is a bit unnecessary if just trying to keep even wear.

[nobil]

why not using a timer? for each unit, you don't need to couple the two of them, less expense and less time of installation. thanks

[Makeit go Right]

Came across one of these changeover panels recently in a Comms Room and I can see how they might be useful. Apart from flipping between the two units for the lead (equal wear), the panel notices if one unit has failed and switches in the standby system, assuming you have 100% standby. Fault lights on the front and contacts for BMS. It also brings in the second one if the load in the room rises outside the capacity of the duty unit.

Only there was quite a hitch getting this particular PACAIR panel to auto-restart the aircon splits after power failed and restored. The Mitsi units were jumpered for auto-restart but the panel messed things up. So, if you have one of these changeover panels, it might be worth checking that it still auto-restarts (ie switch off the power to aircon and see if it all comes back to life again after restoring the power).