Trane RT-PRC031-EN Controls VAV and CV, Space Pressure Control Statitrac, Morning Warm-up Options

Controls VAV and CV

Common to VAV and CV Units

Space Pressure Control - Statitrac™

A pressure transducer is used to measure and report direct space (building) static pressure. The user- defined control parameters used in this control scheme are space static pressure setpoint, space pressure deadband and exhaust enable point.

As the economizer opens, the building pressure rises and once above the exhaust enable point, enables the exhaust fan and dampers or exhaust VFD. The exhaust dampers or VFD then modulate to maintain space pressure within the deadband.

Morning Warm-up Options

This feature may be enabled on all types of factory installed heat units as well as cooling only units configured as “External Heat” (for example, VAV boxes with reheat).

At the conclusion of Unoccupied mode, while the economizer (if supplied) is kept closed, the selected zone is heated to the user-defined Morning Warm-up setpoint. The unit is then released to Occupied mode. There are two types of Morning Warm-up: full capacity or cycling capacity.

Full Capacity Morning Warm-up (MWU)

Full capacity Morning Warm-up uses full heating capacity, and heats the zone up as quickly as possible. Full heating capacity is provided until the Morning Warm-up setpoint is met. At this point, the unit is released to occupied mode.

Cycling Capacity Morning Warm- up (MWU)

Cycling capacity Morning Warm-up provides a more gradual heating of the zone. Normal zone temperature control with varying capacity is used to raise the zone temperature to the

MWU zone temperature setpoint. This method of warm-up is used to overcome the “building sink” effect. Cycling capacity MWU will operate until the MWU setpoint is reached or for 60 minutes, then the unit switches to Occupied mode.

A control algorithm is used to increase or decrease the amount of heat in order to achieve the MWU zone temperature setpoint.

Note: When using the Morning Warm-up option in a VAV heating/cooling air handler, airflow must be maintained through the air handler unit. This can be accomplished by electrically tying the VAV boxes to the VAV box output relay contacts on the Rooftop Module (RTM) or by using changeover thermostats. Either of these methods will assure adequate airflow through the unit and satisfactory heating of the building.

Emergency Override

When a LonTalk communication module is installed, the user can initiate from the Trane Tracer Summit or 3rd party BAS one of five

(5)predefined, not available to configure, Emergency Override sequences. The Humidification output is deenergized for any Emergency Override sequence. Each Emergency Override sequence commands the unit operation as follows:

1.PRESSURIZE_EMERG:

–Supply Fan - On

–Supply Fan IGV / Supply Fan VFD Open/Max (if so equipped)

–Exhaust Fan - Off; Exhaust Dampers Closed (if so equipped)

–OA Dampers - Open; Return Damper - Closed

–Heat - All heat stages off; Mod Heat output at 0 vdc

–Occupied/Unoccupied/VAV box output - Energized

–VOM Relay - Energized (if so equipped)

–Preheat Output - Off

–Return Fan - Off; Exhaust Dampers - Closed (if so equipped)

–Return VFD - Min (if so equipped)

2.EMERG_DEPRESSURIZE:

–Supply Fan - Off

–Supply Fan IGV / Supply Fan VFD - Closed/Min (if so equipped)

–Exhaust Fan - On; Exhaust Dampers Open/Max (if so equipped)

–OA Dampers - Closed; Return Damper - Open

–Heat - All heat stages off; Mod Heat output at 0 vdc

–Occupied/Unoccupied/VAV box output - Energized

–VOM Relay - Energized (if so equipped)

–Preheat Output - Off

–Return Fan - On; Exhaust Dampers - Open (if so equipped)

–Return VFD - Max (if so equipped)

3.EMERG_PURGE:

–Supply Fan - On

–Supply Fan IGV / Supply Fan VFD - Open/Max (if so equipped)

–Exhaust Fan - On; Exhaust Dampers Open (if so equipped)

–OA Dampers - Open; Return Damper - Closed

–Heat - All heat stages off; Mod Heat output at 0 vdc

–Occupied/Unoccupied/VAV box output - Energized

–VOM Relay - Energized (if so equipped)

–Preheat Output - Off

–Return Fan - On; Exhaust Dampers - Open (if so equipped)

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