Orion-system VCC-X Controller Instrukcja Użytkownika Pobierz pdf (Strona 63)

VCC-X Controller Technical Guide

SEQUENCE OF OPERATIONS

Building Pressure Control and MUA

Duct Static Pressure Control for Filter

In order to maintain a constant CFM through the supply air ducts on

a mixed air CAV unit, the VCC-X can utilize a Duct Static Pressure

Sensor (used to monitor the discharge pressure) in conjunction with

a Supply Fan VFD. If the ﬁ lters are getting dirty, the VCC-X will

ramp up the VFD to compensate for the decrease in airﬂ ow. To utilize

this feature, the unit must be conﬁ gured to use VFD Fan Control.

This feature cannot be used if this is a VAV or Zoning application

with typical Duct Static Pressure Control, or if this unit has been

conﬁ gured for Single Zone VAV operation.

Building Pressure Control

The VCC-X can maintain Building Static Pressure anytime the

Supply Fan is operating. A Building Pressure Transducer must be

connected to the VCC-X EM1 Expansion Module. The following

are the available control options.

Direct Acting Building Pressure Control

• On/Off Exhaust Fan—If an On/Off Exhaust Fan is

being used, a relay output must be conﬁ gured for

“Exhaust Fan”. This relay will energize whenever the

Building Pressure rises above the Building Pressure

Setpoint by the Deadband amount. The relay will de-

energize when the Building Pressure falls below the

Building Pressure Setpoint by the Deadband amount.

• Exhaust Fan VFD or Modulating Exhaust

Damper—If conﬁ gured for Modulating Exhaust, a user-

adjustable voltage output (AOUT4 – Building Pressure

Output on the VCC-X Controller) will be used to control

this fan or damper. An Exhaust Relay can be conﬁ gured

if necessary to enable the fan or damper. Whenever the

Building Pressure rises above the Building Pressure

Setpoint by the Deadband amount, the Exhaust Fan

Relay will energize and the Modulating Signal will

activate to control to the Building Pressure Setpoint.

If the Building Pressure falls below the Building

Pressure Setpoint by the Deadband amount,

the Modulating Signal will modulate towards 0% as it

attempts to maintain the Building Pressure Setpoint.

The Exhaust Fan Relay is energized whenever the

Modulating Signal is above 0%.

Reverse Acting Building Pressure Control

• Outdoor Air Damper—If this option is conﬁ gured,

the VCC-X will use the user-adjustable Economizer/

Outdoor Air Damper output signal (AOUT2 –

Economizer Control Signal) to maintain the Building

Pressure Setpoint. Whenever the Building Pressure

falls below the Building Pressure Setpoint by the

Deadband amount, the modulating Economizer Output

Signal will modulate the damper open to control to

the Building Pressure Setpoint. If the Building Pressure

rises above the Building Pressure Setpoint by the

Deadband amount, the damper will modulate towards

closed as it attempts to maintain the Building Pressure

Setpoint. When this option is selected, no Economizer

free cooling or CO

IAQ operation will be available.

• Supply Fan VFD—Contact WattMaster regarding this

Reverse Acting Building Pressure Control option. It

should not be used in most applications. If this option

is selected, the user-adjustable Supply Fan VFD Output

(AOUT1 on the VCC-X) will be used to control the

Supply Fan VFD to maintain the Building Pressure

Setpoint in similar fashion to the Outdoor Air Damper

control described above.

MUA Operation

• Occupied Mode—The VCC-X will use the normal

Cooling and Heating Mode Enable Setpoints (not the

Hood On Setpoints) in conjunction with the Outdoor Air

(OA) temperature sensor to determine the mode of

operation. The Outdoor Air Dewpoint Setpoint will

initiate the Dehumidiﬁ cation Mode. See the Cooling,

Heating and Dehumidiﬁ cation Modes of Operation

sections for those details. The Outdoor Air Damper will

be modulated to the Economizer Minimum Damper

Position (normally set at 100% for a MUA unit).

•

Unoccupied Mode—Normally, an MUA unit is off

during the Unoccupied Mode. However, if the unit has

Return Air, it can be conﬁ gured to operate as a

recirculating Night Setback Controlled unit during

Unoccupied Hours. This is accomplished by simply

conﬁ guring Night Setback Temperature Setpoints

(anything other than the default 30ºF) on a unit that is

also conﬁ gured for Outdoor Temperature Control

(MUA). With this conﬁ guration, when the unit goes

Unoccupied, it will close the Outdoor Air Damper and

begin to use a Space Temperature Sensor in conjunction

with the existing Heating and Cooling Setpoints, offset

by the Night Setbacks, to make Night Setback calls. If a

Space Humidity Sensor is installed, and the unit is

conﬁ gured for Night Humidity control, the VCC-X

Controller will use the Space Humidity Setpoint for

unoccupied Dehumidiﬁ cation calls.

1 2 ... 58 59 60 61 62 63 64 65 66 67 68 ... 119 120

Komentarze do niniejszej Instrukcji

Brak uwag

Orion-system VCC-X Controller Instrukcja Użytkownika Strona 63

Komentarze do niniejszej Instrukcji

Powiązane produkty i podręczniki dla Sprzęt komputerowy Orion-system VCC-X Controller