Trane VAV VV550 LonTalk Скачать руководство пользователя страница 60

Страница: 60 / 116

VAV-SVP01A-EN

VAV VV550 Controller Device Home Tabs: Instructions

Balancing tool to calculate this value and balance the VAV box. Normally, you should not need to
change this value here.

Note:

The flow offset is calculated only for two-point balancing, which requires reading both the
maximum and minimum airflows during balancing. Two-point balancing ensure greater
accuracy over the entire range of air valve operation. Only controllers that support the Flow
Measurement Offset network variable, such as the VAV VV550/551 Controller, can use two-
point balancing.

Flow Gain:

The flow gain is used to calibrate the value reported by the flow sensor so that the

reported airflow matches the actual airflow. The flow gain is determined during the air balancing
process. A testing, adjusting, and balancing professional will use the Rover Air and Water
Balancing tool to calculate this value and balance the VAV box. Normally, you should not need to
change this value here.

Minimum Delta:

The minimum amount of change in the primary airflow required before airflow

and the airflow setpoint are communicated on the Comm5 link. The percentage of change required
is based on the nominal airflow. For example, if the nominal airflow is 1000 cfm and the minimum
delta is 2%, the primary airflow must increase or decrease by 20 cfm before the change is
communicated on the Comm5 link.

Ventilation Setup

A Tracer Summit building automation system is required for accurate ventilation control. The
Tracer Summit VAS Comm5 application calculates the ventilation setpoint and coordinates the air
handler and VAV boxes.

Occupied Setpoint:

During the occupied mode, this setpoint is the active setpoint for ventilation.

Occupied Standby Setpoint:

During the unoccupied mode, this setpoint is the active setpoint

for ventilation.

Space CO

Setup (CO

sensor communicated value only)

Low Limit:

The controller adjusts the ventilation setpoint only when the CO2 concentration falls

within the high and low limits. When the CO2 concentration falls below the low limit, this indicates
that the zone is most likely unoccupied and that a minimum of ventilation air is required to ventilate
the zone.

High Limit:

The controller adjusts the ventilation setpoint only when the CO2 concentration falls

within the high and low limits. When the CO2 concentration rises above the high limit, this indicates
that the zone is most likely at its maximum design occupancy and that a maximum of ventilation
air is required to ventilate the zone.

Flow Setpoints Setup

Minimum Airflow:

Although the VAV VV550 Controller will read flow down to 5% of cataloged,

the range of MIN FLOW settings is 0%, or 10% to 100% of cataloged. The VAV VV550 Controller will
not drive its flow below this minimum flow value under normal operating conditions while in the
cool mode. Cool mode occurs when cool air is in the supply duct. The entry in the Cooling Minimum
field must be less than or equal to the entry in the Maximum field.

Maximum Airflow:

This range is 10% to 100% of the unit's cataloged CFM size. Cooling and

heating flow can be edited to zero.The VAV VV550 Controller will not drive its flow above this
maximum flow value under normal operating conditions while in the Cool mode. Cool mode
occurs when cool air is in the supply duct. The entry for Maximum Flow must be greater than or
equal to the entry in any of the Minimum fields.

Standby Minimum Airflow:

Occupied standby mode is used to reduce the heating and cooling

demands during the occupied hours when the space is unoccupied. It can be activated for a
classroom currently not in use. Standby Minimum is the minimum amount of airflow desired
during this mode.