EXCEL 10 W7750A,B,C CONSTANT VOLUME AHU CONTROLLER
11 74-2958—1
PWM
Pulse Width Modulated output; allows analo
modulatin
control of e
uipment usin
a di
ital output
on the controller.
RTD
Resistance Temperature Detector; refers to a t
pe of
temperature sensor whose resistance output chan
es
accordin
to the temperature chan
e of the sensin
element.
Subnet
A L
ON
W
ORKS
Bus se
ment that is separated b
a
router from its Q7750A Zone Mana
er.
TOD
Time-Of-Da
; the schedulin
of Occupied and
Unoccupied times of operation.
TPT
Twisted Pair Transceiver.
VA
Volt Amperes; a measure of electrical power output or
consumption as applies to an ac device.
Vac
Volta
e alternatin
current; ac volta
e rather than dc
volta
e.
VAV
Variable Air Volume; refers to either a t
pe of air
distribution s
stem, or to the W7751 Excel 10 VAV Box
Controller that controls a sin
le zone in a variable air
volume deliver
s
stem.
VOC
Volatile Or
anic Compound; refers to a class of
common pollutants sometimes found in buildin
s.
Sources include out-
assin
of construction materials,
production-line b
-products, and
eneral cleanin
solvents. A VOC is occasionall
used as a measure of
indoor air
ualit
.
W7750
The model number of the Excel 10 CVAHU
Controllers
also see CVAHU
.
W7751
The model number of the Excel 10 VAV Box
Controllers
also see VAV
.
Wall Module
The Excel 10 Space Temperature Sensor and
other optional controller inputs are contained in the
T7770 or the T7560A,B Wall Modules. See Application
Step 5. Order E
uipment for details on the various
models of Wall Modules.
XBS
Excel Buildin
Supervisor; a PC based tool for
monitorin
and chan
in
parameters in C-Bus devices.
Construction
Controllers
The Excel 10 W7750 Controller is available in three different
models. The W7750A Model, which is a low cost controller
made for simple sin
le zone air handlers and heat pump
controls. The W7750B,C Models are intended for more
complex applications.
The W7750B,C Models use Triacs for their di
ital outputs,
where as the W7750A Model uses dr
-contact rela
s. The
W7750C Model also has three analo
outputs available on
terminals 16, 17 and 18.
All wirin
connections to the controller are made at screw
terminal blocks. Connection for operator access to the
L
ON
W
ORKS
Bus is provided b
plu
in
the SLTA connector
cable into the L
ON
W
ORKS
Bus communications
ack.
The W7750A,B,C Models consist of a sin
le circuit board that
is mounted in a sheet metal subbase and protected b
a
factor
snap-on cover. The three controllers have the same
ph
sical appearance except for terminals 16 throu
h 20
W7750A
and different labels next to the wirin
terminals
see Fi
. 3, 5 or 6
. Wires are attached to the screw terminal
blocks on both sides of the controller. The controllers mount
with two screws
see Fi
. 4 or 7
. The W7750 can also be
mounted usin
DIN rail. To mount the W7750 on DIN rail,
purchase two DIN rail adapters
obtain locall
part number
TKAD, from Thomas and Betts, see Fi
. 8, then snap onto
standard EN 50 022 35 mm b
7.5 mm
1-3/8 in. b
5/16 in.
DIN rail. DIN rail is available throu
h local suppliers.
A channel in the cover allows the controller status LED to be
visible when the cover is in place. There are no field-
serviceable parts on the circuit board and, therefore,
it is
intended that the cover never be removed
.
The W7750A,B,C can be mounted in an
orientation.
Ventilation openin
s were desi
ned into the cover to allow
proper heat dissipation re
ardless of the mountin
orientation.
See Fi
. 4 and 7.
The input/output and control differences between the two
models are summarized in Table 2. The I/O points in Table 2
are the free I/O points that are not reserved for Wall Module
use.
Table 2. List of Differences in W7750A and W7750B,C Controllers.
*The T7770 or the T7560 Wall Modules includes I/O points for
two analo
inputs for the space temperature and the setpoint
knob, a di
ital input for the B
pass pushbutton, and a di
ital
output for the LED B
pass Indicator. These W7750 I/O
points are confi
urable, but are normall
used for the Wall
Module.
W7750A Model W7750B,C Models
Digital Outputs
Six Rela
Outputs Ei
ht Triac Outputs
Digital Inputs
Two Four
Wall Module
One* One*
Analog Outputs
None Three 4 to 20 mA Outputs
W7750C onl
Analog Inputs
One
Resistive Input Onl
Four
Two Resistive and two Volta
e/Current Inputs
DC Power
None 20 Vdc available to power optional sensors
Floating (Series 60) Control
Economizer Onl
Heatin
, Coolin
, and/or Economizer
PWM Control
None Heatin
, Coolin
, and/or Economizer
