Commissioning Instructions

Step 9 – Fault suppression
29
Unrestricted
A6V12035398
Step 9 – Fault suppression
Condition of AHU Mode
SplyAir11 – Central application function
Fault Detection and Diagnostics for DXR is designed to work with SplyAir11 Central
application function (“Supply chain air 11, for central air handling unit (AHU)”).
When the DXR is connected to the SplyAir11 Central application function (“Supply
chain air 11, for central air handling unit (AHU)”), the Supply air flow fault, Supply
heating temp fault, and Extract air flow fault will be suppressed whenever AHU Mode is
set to Off by the Central function. (object in SplyAir11 is AhuModCndVal, “Condition
value of air handling unit mode”. )
AHU Mode is binary:
0:Inactive means FDD calculations are disabled in the DXR.
1:Active means FDD calculations are enabled in the DXR.
Note:
If the DXR is not connected to the Central AF (SplyAir11 not defined/not present) then
Supply air flow fault, Supply heating temp fault, Dual Duct air flow fault, and Extract
air flow fault are always enabled – they are not affected by the value of AHU Mode.
Alternatively, the FDD faults will be enabled/disabled if AHU Mode object is manually
overridden/commanded.
TESTING: When it is needed to test the FDD faults prior to, or without, Central AF
functions.
o The AHU MODE point can be manually put out-of-service and commanded to
On or Off.
o CAUTION: It will be necessary for the restoration of default fault detecton
functions and/or Central AF functions, to return AHU MODE out-of-service to
‘No‘ and restart the DXR (either by on-line “Restart-controller“ or by power
cycling the DXR).
Note:
Fault suppression will not work for segments that only have an extract terminal
defined.