Local and remote control of air conditioning by BRC1D52 controllers

[Griffin]

We have an aircon system for 3 rooms. Temperature control of these rooms has been erratic. Building was built in 2008, but when I tried looking at the O&M Manual much of it says 'to follow'. Each room has a local Daikin BRC1D52 controller, there is also a BMS which I have interrogated using its IQView touch panel and discovered it monitors the CO2 and temperature in the rooms. On Friday 2 of the Daikin controllers indicated they were under control from elsewhere (presumably the BMS) and one wasn't. Today it's the other way round. No one in the school has a clue why they are different, why they have swapped or how to control the system.

Can anyone suggest how I can control where the aircon from a room is controlled from?

[Griffin]

Having checked on the controllers in the rooms in between each lesson today, I realise that the control switches from remote to the local controllers apparently at will, though there must be a trigger. Can anyone tell me what makes it happen?

[install monkey]

ur iq view- is a trend bms, open the control panel door and look for the wiring diagram, this will tell you how much is controlled via the bms, you say it moniters co2- so there will be fresh air via fan /air handling unit or a lossnay heat recovery unit, temperatures can become erratic if supply air is cold and it isnt tempered by lphw coil or electric duct heater- typically needs to be 16deg to not influence the brc controller.
the trend outstation will control on/of- via a t1t2 connection on each indoor unit- unless the indoors are wall mounts then there will be extrnal krp adaptor again with the t1t2 connections (volt free open contact off,closed on) this will be switched via a relay within the control panel.

[frank]

Best get someone who understands Daikin controls in to have a look and diagnose...after all, this is how we make our living ;)

[The Viking]

Are you by any chance in Isleworth?

:cool:

[r.bartlett]

Are you by any chance in Isleworth?

:cool:

Rugby aparently

[The Viking]

Hmm,
Sound suspiciously like a system I commissioned a few years ago...

The designer had some extremely pink tinted views on energy conservation and demanded that the A/C system would only run if the CO2 monitoring BMS system called for fresh air and the room temps were above a treshold.

I could only run the A/C systems whith the BMS interface "by-passed" as the TREND engineer on site could not get all the external sensors to operate together...
My bet is that those units haven't run since my commissioning.

:cool: