Honeywell W7750A Manual

A SERVICE OF

next previous

EXCEL 10 W7750A,B,C CONSTANT VOLUME AHU CONTROLLER

74-2958—128

NOTE: Durin

g

all modes all di

g

ital and analo

g

ph

y

sical

inputs are periodicall

y

read, the dia

g

nostic output

network variables can be polled, the input network

variables are received, and the output network

variables are sent periodicall

y

.

UNOCCUPIED

Controller occupanc

y

mode was

overridden to Unoccupied mode

Network input

(

DestManOcc

)

containin

g

a time-of-da

y

schedule

override si

g

nal of UNOCCUPIED from the Excel 10 Zone Mana

g

er or

other L

ON

W

ORKS

Bus device.

BYPASS

Controller occupanc

y

mode was

overridden to B

y

pass the current

Unoccupied mode

DI

(

B

y

pass

)

was pressed, and the B

y

pass duration timer has not

y

et

expired, or the network input DestManOcc has a value of BYPASS.

NOT

ASSIGNED

No B

y

pass action No Override input received.

Operational Modes (User Address: StatusMode)

START-UP

AND WAIT

On power-up, provides a sta

gg

ered

start se

q

uence to evenl

y

appl

y

the load

to the electrical s

y

stem.

This mode occurs on controller power-up, and after downloadin

g

to the

controller from the confi

g

uration tool. Temperature control loops are

disabled.

COOLING

The Excel 10 is controllin

g

the Coolin

g

mode.

Space temperature has risen above the current coolin

g

setpoint, or the

network input

(

DestHvacMode

)

is COOL.

HEATING

The Excel 10 is controllin

g

the Heatin

g

mode.

Space temperature has fallen below the current heatin

g

setpoint, or the

network input

(

DestHvacMode

)

is HEAT.

EMERGENCY

HEAT

Compressors are disabled and onl

y

Auxiliar

y

Heat sta

g

es are allowed to

operate.

The network input

(

DestManHvacMode

)

is EMERG_HEAT.

OFF MODE

The heat/cool control is turned off

immediatel

y

. The node is not runnin

g

its

normal temperature control.

Network input

(

DestManMode

)

containin

g

AHU operational mode

information from C-Bus has value of MORNING WARM-UP.

DISABLED

MODE

The heat/cool control and frost

protection are turned off immediatel

y

.

The node is not runnin

g

its normal

temperature control.

–

SMOKE

EMERGENCY

The node has entered a smoke

emer

g

enc

y

. The fan and dampers are

then set to the conditions confi

g

ured b

y

SmkCtlMode. The control remains in

SMOKE_ EMERGENCY until power is

c

y

cled or the node receives

DestEmer

g

Cmd set to

EMERG_NORMAL.

Network input

(

DestEmer

g

Cmd

)

containin

g

smoke control si

g

nal from

another L

ON

W

ORKS

Bus device has value of SMOKE_EMERG.

FREEZE

PROTECT

The temperature control is set to HEAT

with the setpoint set to the frost limit

setpoint 46.4°F

(

8°C

)

.

The Window di

g

ital input detects an open window.

MANUAL

POSITION

The ph

y

sical outputs are bein

g

controlled manuall

y

. The temperature

control loop is turned off.

T

y

picall

y

this is done b

y

the user throu

g

h E-Vision or XBS b

y

settin

g

the point DestManMode to MANUAL mode.

FAN ONLY

Control al

g

orithm is disabled, except

that the fan is turned on.

The space temperature sensor has failed, or the network input

(

DestHvacMode

)

is FAN ONLY.

DISABLED

Control al

g

orithm is shut off. Network input

(

DestManMode

)

containin

g

AHU operational mode

information from an operator or the network that has a value of

DISABLED.

Table 5. Modes Of Operation For The Excel 10 W7750 Controller (Continued).

Mode Description Events causing a controller to switch to this mode