Carrier RTU OPEN 11-808-427-01 Especificaciones descargar pdf (Pagina 54)

Sequence of Operation

48 RTU Open

The following conditions must be true for the

Indoor Air CO2

algorithm to operate:

• The system is occupied

• The supply fan has been started for at least 30 seconds

• The CO2 sensor has a valid reading

As the air quality within the space changes, the minimum position of the economizer damper changes, which

allows more or less outdoor air into the space, depending on the relationship of the indoor air CO2 level to the

differential setpoint.

The

Indoor Air CO2

algorithm calculates a minimum position value using a PID loop. The CO2 minimum

damper position is then compared against the

Vent Dmpr Pos / DCV Min Pos

setpoint and the greatest value

becomes the final minimum damper position of the economizer output.

The degree to which the outside air damper may be opened by the

Indoor Air CO2

algorithm is limited by the

DCV Max Vent Damper Pos

setpoint, which is adjustable between ten and sixty percent (10 – 60%).

Heating

The specific heating sequence is determined by the controller's application and configuration. The RTU Open

controls up to two stages of gas or electric heating with an additional output for a

Reversing Valve

(Heat

Pump applications).

The following conditions must be true for the heating algorithm to operate:

• The

Outdoor Air Temperature

is less than the

Heating Lockout Temperature

setpoint

• The indoor fan has been ON for at least 30 seconds

• The unit has a valid

Supply Air Temperature

input

• The unit has a valid

Space Temperature

input

• Neither Cool mode nor economizer are active and the time guard between modes has expired

The heating relays are controlled by the Heating Control PID Loop and Heating Stages Capacity algorithm,

which calculate the desired number of stages to satisfy the space by comparing the

Space Temperature

the:

•

Effective Occupied Heating Setpoint

when occupied

•

Effective Unoccupied Heating Setpoint

when unoccupied

When the heating algorithm preconditions have been met, the heating is energized in stages. Anti-recycle

timers are employed to protect the equipment from short-cycling. There are fixed one minute minimum on

and off times for each heating output.

During heating operation, the RTU Open may reduce the number of active stages if the rooftop

Supply Air

Temperature

exceeds the

Maximum Heating SAT

setpoint. A heat stage turned off in this fashion may be

started again after the normal time-guard period has expired, if the

Supply Air Temperature

has decreased

below the

Maximum Heating SAT

setpoint.

1 2 ... 49 50 51 52 53 54 55 56 57 58 59 ... 87 88

Comentarios a estos manuales

Sin comentarios

Carrier RTU OPEN 11-808-427-01 Especificaciones Pagina 54

Comentarios a estos manuales

Relacionado con productos y manuales para Acondicionadores de aire del sistema de división Carrier RTU OPEN 11-808-427-01