Step 4. prepare wiring diagrams, General considerations, W7761a devices – Honeywell W7761A User Manual

Page 24

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EXCEL 10 W7761A INPUT/OUTPUT DEVICE

24

74-2699

Make earth ground connections with the shortest possible wire run using 14 AWG (2.0 mm

2

) wire. A good earth

ground is essential for W7761A operation. Ideally, connect the earth ground to the ground bus at a motor control
center or circuit breaker panel. However, if the nearest ideal earth ground is inaccessible, consider an alternate
source for earth ground. Metal water pipe is generally a good ground, but do not use sprinkler pipe if prohibited by
local codes. Attention must be given when duct work, conduit, or rebar are to be considered as ground sources. It
is the responsibility of the installer to assure that these structures are tied back to a known earth ground.

Step 4. Prepare Wiring Diagrams

General Considerations

The purpose of this step is to assist the application engineer in developing job drawings to meet job specifications. Wiring
details are included for the W7761A device the T7770A,B,C,D wall module (sensor—current feature that can be used with the
RIO Device) and the T7780 DDWM. The drawings detail I/O, power, and communication bus wiring connections.

NOTE:

For field wiring, when two or more wires are to be attached to the same connector block terminal, be sure to twist
them together. Deviation from this rule can result in improper electrical contact. See Fig. 15.

The connector block terminals on the W7761A and on the T7770 accept 14 through 22 AWG (2.0 to 0.34 mm

2

) wire. Table 6

lists wiring types, sizes, and length restrictions for Excel 10 products.

Table 6 . Field Wiring Reference Table.

Wire

Function

Recommended

Minimum Wire

Size AWG (mm

2

)

Construction

Specification

or

Requirement

Vendor Wire Type

Maximum Length

ft (m)

E-Bus
(Plenum)

22 AWG
(0.34 mm

2

)

Twisted pair solid conductor,
nonshielded or Echelon

approved shielded cable.

Level IV 140°F
(60°C) rating

Honeywell
AK3791 (one twisted pair)
AK3792 (two twisted pairs)

Refer to E-Bus
Wiring Guidelines
for maximum
length

E-Bus
(Non-
Plenum)

22 AWG
(0.34 mm

2

)

Twisted pair solid conductor,
nonshielded or Echelon

approved shielded cable.

Level IV 140°F
(60°C) rating

Honeywell
AK3781 (one twisted pair)
AK3782 (two twisted pairs)

Refer to E-Bus
Wiring Guidelines
for maximum
length

Input
Wiring
Sensors
Contacts

18 to 22 AWG
(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.

140°F (60°C)
rating

Standard thermostat wire

1000 ft (305m)
for 18 AWG
200 ft (61m)
for 22 AWG

Output
Wiring
Actuators
Relays

14 AWG (2.0
mm

2

)

(18 AWG (1.0
mm

2

) acceptable

for short runs)

Any pair nonshielded (use
heavier wire for longer
runs).

NEC Class 2
140°F (60°C)
rating

Honeywell
AK3702 (18 AWG)
AK3712 (16 AWG)
AK3754 (14 AWG)
or equivalent

Limited by line-loss
effects on power
consumption.
(See Line Loss
subsection.)

Power
Wiring

14 AWG
(2.0 mm

2

)

Any pair nonshielded (use
heavier wire for longer
runs).

NEC Class 2
140°F (60°C)
rating

Honeywell
AK3754 (14 AWG)
twisted pair
AK3909 (14 AWG) single
conductor or equivalent

Limited by line-loss
effects on power
consumption.
(See Line Loss
subsection.)

W7761A Devices

Fig. 16 through 20 illustrate W7761A Device wiring for various configurations. Connections to the wall module terminals (4
through 6) and the communications terminals (14 and 15) are made at terminal blocks. Connection for access to the E-Bus is
provided by plugging the connector into the communications jack.
NOTE:

If an Excel 10 W7761A Device or Zone Manager is not connected to a good earth ground, the device internal transient
protection circuitry is compromised and the function of protecting the device from noise and power line spikes cannot
be fulfilled. This can result in a damaged circuit board and require replacing the device.

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