Honeywell W7750A User Manual
EXCEL 10 W7750A,B,C CONSTANT VOLUME AHU CONTROLLER
74-2958—1
36
Table 9. Field Wiring Reference Table (Honeywell listed as AK#### or equivalent).
W7750 Controllers
Fig. 27 through 35 illustrate W7750A,B,C Controller wiring for
various configurations. Connections to the wall module
terminals (2 through 6) and the communications terminals (14
and 15) are made at terminal blocks. Connection for access to
the L
various configurations. Connections to the wall module
terminals (2 through 6) and the communications terminals (14
and 15) are made at terminal blocks. Connection for access to
the L
ON
W
ORKS
Bus is provided by plugging the connector into
the communications jack.
Fig. 25. Attaching two or more wires at terminal blocks.
The W7750B provides a jumper to select High-Side or Low-
Side switching of the digital outputs. Fig. 26 shows the
W7750B High-Side/Low-Side selectable switching. (See
wiring diagrams, Figs. 30 through 34.)
Side switching of the digital outputs. Fig. 26 shows the
W7750B High-Side/Low-Side selectable switching. (See
wiring diagrams, Figs. 30 through 34.)
Fig. 26. W7750B High-Side/Low-Side selectable switching
and jumper location.
NOTE:
If an Excel 10 W7750A,B,C Controller or Zone
Manager is not connected to a good earth ground,
the controller internal transient protection circuitry is
compromised and the function of protecting the
controller from noise and power line spikes cannot
be fulfilled. This can result in a damaged circuit
board and require replacing the controller.
Manager is not connected to a good earth ground,
the controller internal transient protection circuitry is
compromised and the function of protecting the
controller from noise and power line spikes cannot
be fulfilled. This can result in a damaged circuit
board and require replacing the controller.
See Table 10 for a description of the W7750A terminals.
Wire
Function
Recommended
Minimum Wire
Size AWG (mm
2
)
Construction
Specification
or
Requirement
Vendor Wire Type
Maximum Length ft.
(m)
L
ON
W
ORKS
Bus
(Plenum)
(Plenum)
22 AWG
(0.34 mm
(0.34 mm
2
)
Twisted pair solid
conductor, nonshielded
or Echelon approved
cable.
conductor, nonshielded
or Echelon approved
cable.
Level IV
140°F (60°C)
rating
140°F (60°C)
rating
Honeywell
AK3791 (one twisted pair)
AK3792 (two twisted pairs)
AK3791 (one twisted pair)
AK3792 (two twisted pairs)
Refer to L
ON
W
ORKS
Bus
Wiring Guidelines for
maximum length
maximum length
L
ON
W
ORKS
Bus (Non-
Plenum)
Plenum)
22 AWG
(0.34 mm
(0.34 mm
2
)
Twisted pair solid
conductor, nonshielded
or Echelon approved
cable.
conductor, nonshielded
or Echelon approved
cable.
Level IV
140°F (60°C)
rating
140°F (60°C)
rating
Honeywell
AK3781 (one twisted pair)
AK3782 (two twisted pairs)
AK3781 (one twisted pair)
AK3782 (two twisted pairs)
Refer to L
ON
W
ORKS
Bus
Wiring Guidelines for
maximum length
maximum length
Input
Wiring
Sensors
Contacts
Wiring
Sensors
Contacts
18 to 22 AWG
(1.0 to 0.34 mm
(1.0 to 0.34 mm
2
)
Multiconductor (usually
five-wire cable bundle).
For runs >200 ft. (61m)
in noisy EMI areas, use
shielded cable.
five-wire cable bundle).
For runs >200 ft. (61m)
in noisy EMI areas, use
shielded cable.
140°F (60°C)
rating
rating
Standard thermostat wire
1000 ft. (305m) for 18
AWG 200 ft. (61m) for 22
AWG
AWG 200 ft. (61m) for 22
AWG
Output
Wiring
Actuators
Relays
Wiring
Actuators
Relays
14 AWG (2.0 mm
2
)
18 AWG (1.0 mm
2
)
acceptable for
short runs)
short runs)
Any pair nonshielded
(use heavier wire for
longer runs).
(use heavier wire for
longer runs).
NEC Class 2
140°F (60°C)
rating
140°F (60°C)
rating
Honeywell
AK3702 (18 AWG)
AK3712 (16 AWG)
AK3754 (14 AWG)
AK3702 (18 AWG)
AK3712 (16 AWG)
AK3754 (14 AWG)
Limited by line-loss
effects on power
consumption. (See Line
Loss subsection.)
effects on power
consumption. (See Line
Loss subsection.)
Power
Wiring
Wiring
14 AWG (2.0 mm
2
) Any pair nonshielded
(use heavier wire for
longer runs).
longer runs).
NEC Class 2
140°F (60°C)
rating
140°F (60°C)
rating
Honeywell
AK3754 (14 AWG) twisted
pair AK3909 (14 AWG)
single conductor
AK3754 (14 AWG) twisted
pair AK3909 (14 AWG)
single conductor
Limited by line-loss
effects on power
consumption. (See Line
Loss subsection.)
effects on power
consumption. (See Line
Loss subsection.)
1/2
(13)
STRIP 1/2 IN. (13 MM)
FROM WIRES TO
BE ATTACHED AT
ONE TERMINAL.
FROM WIRES TO
BE ATTACHED AT
ONE TERMINAL.
1.
2.
TWIST WIRES
TOGETHER WITH
PLIERS (A MINIMUM
OF THREE TURNS).
TOGETHER WITH
PLIERS (A MINIMUM
OF THREE TURNS).
3.
CUT TWISTED END OF WIRES TO 3/16 IN. (5 MM)
BEFORE INSERTING INTO TERMINAL AND
TIGHTENING SCREW. THEN PULL ON EACH
WIRE IN ALL TERMINALS TO CHECK FOR
GOOD MECHANICAL CONNECTION.
BEFORE INSERTING INTO TERMINAL AND
TIGHTENING SCREW. THEN PULL ON EACH
WIRE IN ALL TERMINALS TO CHECK FOR
GOOD MECHANICAL CONNECTION.
M17207
U3
Q38
J2
JUMPER
TERMINAL 24
J2 IS LOCATED NEAR TERMINAL 24 (COVER REMOVED).
W7750B IS FACTORY-DELIVERED WITH JUMPER ON HIGH-SIDE
(PINS CLOSEST TO TERMINAL BLOCK). LOW-SIDE PINS ARE TWO
PINS CLOSEST TO Q38.
(PINS CLOSEST TO TERMINAL BLOCK). LOW-SIDE PINS ARE TWO
PINS CLOSEST TO Q38.
1
1
2
2
M16418A