Commissioning Instructions

ManualsBrandsSiemens ManualsBuilding automationDual Duct Variable Volume with Two Inlet Sensors, (DCV), Modulating Electric (or HW) Heat and Hot Water (or Electric) Radiator - Templates 14069, 14169, 14369

Step 8 – Fault detection and diagnostics parameters

Unrestricted

A6V12035398

Supply heat temp fault determination

AND

THEN

Supply air Temperature <

Supply air Setpoint minus

temp threshold

Supply air temperature >

Max (Supply air Setpoint,

Primary air Temp) plus

temp threshold

conditions exists for

greater than fault delay

Supply temp

FAULT

AHU MODE = ON

and

Supply Air flow

setpoint > flow

threshold

Normal

YES

Lo Temp

Normal

YES

Hi Temp

AHU MODE = OFF

Supply Air flow

setpoint < flow

threshold

Normal

• For FDD Fault determinations to be enabled, the following conditions must be met.

• DXR object ‘AHU MODE’ (set by central commands) present value is ‘On’ (1)

• See note in Step 9 when AHU MODE is overridden for testing.

• One (or both) of the Supply air flow setpoint 1 (2) must be greater than configuration

parameter ‘Enable VAV flow setpoint’.

• Supply air temperature fault: Hi temp

▪ IF Primary air Temperature is not being updated (e.g. 0C, 32F)

• Fault: Supply air temperature remains greater than Supply air temperature setpoint by the

differential Supply air heating temperature fault tolerance for the duration of Supply air

heating temp fault delay (default 600 seconds).

• Normal: When the supply temperature and the supply temperature setpoint returns to be

within the fault tolerance, the fault will be reset automatically.

▪ IF Primary air Temperature is updated by the central functions or field panel:

• Fault: Supply air temperature remains greater than

The larger of Supply air temperature setpoint and Primary air temperature by the

differential Supply air heating temperature fault tolerance for the duration of Supply air

heating temp fault delay (default 600 seconds).

• Normal: When the supply temperature and the larger of supply temperature setpoint and

Primary air temperature returns to be within the fault tolerance, the fault will be reset

automatically.

• Supply air temperature fault: Low temp

▪ Fault: Supply air temperature remains less than Supply air temperature setpoint by the differential

Supply air heating temperature fault tolerance for the duration of Supply air heating temp fault delay

(default 600 seconds).

• Normal: When the supply temperature and the supply temperature setpoint return to be within the

fault tolerance, the fault will be reset automatically.