Honeywell specifications Prepare Wiring Diagrams, General Considerations, W7761A Devices

EXCEL 10 W7761A INPUT/OUTPUT DEVICE

∙Make earth ground connections with the shortest possible wire run using 14 AWG (2.0 mm2) 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 mm2) wire. Table 6 lists wiring types, sizes, and length restrictions for Excel 10 products.

Table 6 . Field Wiring Reference Table.

Wire	Recommended		Specification
	Minimum Wire		or		Maximum Length
Function	Size AWG (mm2)	Construction	Requirement	Vendor Wire Type	ft (m)
E-Bus	22 AWG	Twisted pair solid conductor,	Level IV 140°F	Honeywell	Refer to E-Bus
(Plenum)	(0.34 mm2)	nonshielded or Echelon®	(60°C) rating	AK3791 (one twisted pair)	Wiring Guidelines
		approved shielded cable.		AK3792 (two twisted pairs)	for maximum
					length
E-Bus	22 AWG	Twisted pair solid conductor,	Level IV 140°F	Honeywell	Refer to E-Bus
(Non-	(0.34 mm2)	nonshielded or Echelon®	(60°C) rating	AK3781 (one twisted pair)	Wiring Guidelines
Plenum)		approved shielded cable.		AK3782 (two twisted pairs)	for maximum
					length
Input	18 to 22 AWG	Multiconductor (usually five-	140°F (60°C)	Standard thermostat wire	1000 ft (305m)
Wiring	(1.0 to 0.34 mm2)	wire cable bundle). For runs	rating		for 18 AWG
Sensors		>200 ft (61m) in noisy EMI			200 ft (61m)
Contacts		areas, use shielded cable.			for 22 AWG
Output	14 AWG (2.0	Any pair nonshielded (use	NEC Class 2	Honeywell	Limited by line-loss
Wiring	mm2)	heavier wire for longer	140°F (60°C)	AK3702 (18 AWG)	effects on power
Actuators	(18 AWG (1.0	runs).	rating	AK3712 (16 AWG)	consumption.
Relays	mm2) acceptable			AK3754 (14 AWG)	(See Line Loss
	for short runs)			or equivalent	subsection.)
Power	14 AWG	Any pair nonshielded (use	NEC Class 2	Honeywell	Limited by line-loss
Wiring	(2.0 mm2)	heavier wire for longer	140°F (60°C)	AK3754 (14 AWG)	effects on power
		runs).	rating	twisted pair	consumption.
				AK3909 (14 AWG) single	(See Line Loss
				conductor or equivalent	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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