Refrigerant (R-454B) Detection And Mitigation; Heat Cool Mode Status: Off; Heat Cool Mode Status: Cool - Trane IntelliPak 3 with Symbio 800 Installation, Operation And Maintenance Manual

Sequence of Operation
Refrigerant (R–454B) Detection
and Mitigation
Equipment with R-454B refrigerant requires a refrigerant
detection system based on the refrigerant charge. When
the refrigerant detection system is in a normal state, the
equipment provides normal heating, cooling, and
ventilation.
Figure 44. Heat Cool Mode Status: Off
The VAV Box Relay will be energized for Full Airflow and
supply fan will go to minimum speed.
The unit will stay in this state until the leak has cleared, or
the failed sensor has been replaced.
VFD bypass is not a requirement for leak detection. This
only explains what action will or will not be taken if a leak is
detected. If the unit has Supply Fan VFD Bypass Installed
and enabled, the supply fan will go to maximum speed. If
the Supply Fan VFD Bypass is installed but disabled AND
the VFD has failed, the supply fan will not start.
Once the leak is cleared, the unit will continue to mitigate
for five minutes. During this five minute mitigation, the
concentration or sensor failure diagnostics will clear but the
mitigation diagnostic will remain. When the five minute time
expires, mitigation will terminate, and the unit will transition
back to normal control.

Heat Cool Mode Status: Cool

When the unit is in Cool mode and a leak is detected or
sensor fails (see the figure below), the same diagnostics
will trigger.
Figure 45. Heat Cool Mode Status: Cool
98

Heat Cool Mode Status: Off

When the unit is in Off mode and a leak is detected or
sensor fails (see the figure below), a diagnostic will trigger.
Heat Cool Mode will transition to "Fan Only". Compressor
Operation is disabled, heating operation is disabled, and
outdoor air dampers are closed all normal operation for
"Off" mode).
The VAV Box Relay will be energized for Full Airflow and
supply fan will stay at the cool mode operating speed which
will be at or above minimum speed. DX Cooling will de-
energize and compressor operation will be disabled. This is
a change to normal operation while in Cool Mode. Heating
will remain disabled, and the unit can continue to
economize if economizing is installed.
The unit will stay in this state until the leak is cleared, or the
failed sensor has been replaced.
VFD bypass is not a requirement for leak detection. This
only explains what action will or will not be taken if a leak is
detected. If the unit has Supply Fan VFD Bypass Installed
and enabled, the supply fan will go to maximum speed. If
the Supply Fan VFD Bypass is installed but disabled AND
the VFD has failed, the supply fan will not start.
Once the leak is cleared, the unit will continue to mitigate
for five minutes. During this five minute mitigation, the
concentration or sensor failure diagnostics will clear but the
mitigation diagnostic will remain. When the five minute time
expires, mitigation will terminate, and the unit will transition
back to normal control.
RT-SVX080A-EN