Honeywell EXCEL 10 W7751H User Manual

Excel 10 W7751H Smart VAV Actuator

INSTALLATION INSTRUCTIONS

BEFORE INSTALLATION

The W7751H Smart VAV Actuator is a factory-combined Excel 10 Variable Air Volume (VAV) Box Controller and an ML6174 Direct-Coupled Actuator with De-clutch mechanism. The actuator/controller assembly is field mounted to the VAV box damper shaft similar to the mounting of a standard actuator, and the controller wiring is terminated to the screw terminals that are located under a snap-on cover. See Fig. 1. The Smart VAV Actuator is a Free Topology Transceiver (FTT) L

ONMARK® compliant controller. The W7751H2025 is for

smoke control use.

The ML6174 Direct-Coupled Actuator with De-clutch mechanism (see Fig. 2 for location) allows the installer to manually open or close the VAV box damper connected to the W7751H without power or software tool to command it.

The controller in the W7751H contains a Microbridge flowthrough pressure sensor and communicates via the 78 kilobaud Echelon® L

Triac output loads must draw a minimum current of 25 mA at 24 Vac, 60 Hz nominal. Triac maximum current rating: 77 mA.

The actuator on the W7751H mounts directly onto the VAV box damper shaft and has up to 70 lb-in. torque (8 Nm), 90 degree stroke, and 90 second timing at 60 Hz.

The actuator on the W7751H can accommodate the optional field-installed auxiliary switches.

NOTE: Mounting thermostat/sensor greater than 20 ft from

the W7751H2025 requires 14506944-001 Transient Protectors. They must be installed on the thermostat/ sensor leads from the T7770C pins 3, 4, 5, 6, and 7.

ONWORKS® Bus Network.

INSTALLATION

Horizontally mount the W7751H on the damper shaft and allow clearance for wiring, servicing and module removal. Avoid mounting the W7751H in areas where acid fumes or other deteriorating vapors can attack the metal parts of the actuator, or in areas where escaping gas or other explosive vapors are present. See Fig. 2 for mounting dimensions.

CCW

M19924

Fig. 1. Excel 10 Smart VAV Actuator.

IMPORTANT

The assembly is intended only for horizontal shaft mounting, to assure proper heat dissipation from the controller housing. The Smart VAV Actuator must not be mounted with the controller at the top.

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EXCEL 10 W7751H SMART VAV ACTUATOR

MAINTAIN A MINIMUM DISTANCE OF 3 IN. (76 MM) FROM OTHER DEVICES OR PANELS FOR REMOVING CONTROLLER COVER

1-13/16 (46)

1-5/16 (33)

DE-CLUTCH LEVER

3-3/4 (95)

MAINTAIN A MINIMUM DISTANCE OF 4 IN (100 MM) FROM OTHER DEVICES OR PANELS FOR ATTACHING PNEUMATIC AIR FLOW TUBING

4-1/16 (103)

CCW

3-5/8 (92)

CCW

(25)

1-13/16

(46)

5-7/8 (149)

Fig. 2. W7751H mounting dimensions in in. (mm).

The W7751H assembly is field mounted to the VAV box damper shaft, the same as used for a typical actuator. The actuator on the W7751H opens or closes a damper by driving the damper shaft in either the counterclockwise (CCW) or clockwise (CW) direction. The actuator has a mounting tab on the bottom for securing to a VAV box damper. The mounting tab is accessible through a hole in the controller with its cover removed (see Fig. 3). The tab is sized for a 1/4 in. (6 mm) screw or pin (not included).

The controller enclosure on the W7751H is constructed of a sheet metal housing and a plastic snap-on cover. Controller wiring on the W7751H is terminated to screw terminal blocks located under the snap-on cover. See Wiring section. The sheet metal housing has two 1/2 inch (13 mm) knockouts (see Fig. 2) compatible with 1/2 inch (13 mm) or 3/4 inch (19 mm) conduit.

NOTE: The assembly is intended only for mounting to a

horizontal shaft.

3-3/4

(95)

2-1/8

(54)

3/4

(19)

DE-CLUTCH LEVER

1-15/16 (49)

3/4

(19)

M10523

The W7751H actuator is shipped in the fully clockwise (CW) position (90 degree). The W7751H Assembly must be mounted to a horizontal damper shaft to assure proper heat dissipation from the controller housing. Mount the W7751H so that the actuator is parallel with the VAV box damper housing. In general, it is recommended that a washer or spacer be added between the VAV box damper housing and the actuator mounting tab to keep them parallel. See Fig. 4.

CAUTION

Equipment Damage Hazard. Mounting actuator unevenly with damper housing can damage actuator.

Mount actuator flush with damper housing or add spacer between mounting tab and damper box housing. (See Fig. 4.)

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EXCEL 10 W7751H SMART VAV ACTUATOR

CCW

PULL TOP OF COVER OUT, THEN DOWN, FOR REMOVAL

CCW

CIRCUIT BOARD TERMINAL BLOCKS

CCW

MOUNTING TAB

M10000

Fig. 3. Cover removal and mounting tab/terminal block access.

3. The direction the damper shaft rotates to open the

damper (CW or CCW), see Fig. 5.

1MM (1/32 IN.)

4. The damper opening angle (45, 60, or 90 degrees).

TYPE A DAMPER

FLOW

CW TO OPEN, CCW TO CLOSE

TYPE B DAMPER

FLOW

M2067B

1MM

Fig. 5. Determining rotation direction (CW or CCW)

(1/32 IN.)

M20884

Fig. 4. Mounting W7751H to VAV box damper housing

when actuator is not parallel to VAV box damper housing.

Before mounting the W7751H onto the VAV box damper shaft, determine the following:

1. The damper shaft diameter, 3/8 to 1/2 in. (10 to 13 mm).

2. If the length of the VAV box damper shaft is less than

1-3/8 in. (35 mm), use the Short Shaft Adapter Kit (not

If damper shaft diameter is 3/8 inch (10 mm) round or square, use part 201391 Shaft Adapter (shipped with the W7751H Smart VAV Actuator). Ensure it is placed opposite set screws. See Fig. 6. The adapter centers a 3/8 in. (10 mm) shaft in the hub. Failure to use the adapter on a 3/8 in. (10 mm) shaft causes the mounting tab to loosen. A 1/2 in. (13 mm) shaft does not require the use of the adapter.

CCW TO OPEN, CW TO CLOSE

for damper opening.

included), part no. 4074EVK.

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EXCEL 10 W7751H SMART VAV ACTUATOR

SHAFT ADAPTER

M2064

Fig. 6. Use Damper Shaft Adapter for 3/8 in. (10 mm)

diameter round or square damper shafts.

The W7751H is shipped with the actuator rotated in the fully clockwise (CW) position. The installation procedure varies depending on the damper direction and angle:

1. If the damper rotates clockwise (CW) to open, and the angle of the damper open to closed is 90 degrees, manually open the damper fully to the clockwise direction and mount the W7751H to the VAV damper box and shaft. Tighten the Allen set screws. The part no. 201614 Range Stop Pin, which is shipped with the W7751H Smart VAV Actuator, is unnecessary. When the W7751H closes, the damper rotates CCW 90 degrees to fully close.

2. If the damper rotates clockwise (CW) to open, and the angle of the damper open to closed is 45 or 60 degrees, manually open the damper fully to the clockwise direction and mount the W7751H to the VAV damper box and shaft. Tighten the Allen set screws. Insert the part no. 201614 Range Stop Pin, which is shipped with the W7751H Smart VAV Actuator, in either the 45 or 60 degree CCW slot, whichever applies (see Fig. 7). The range stop pin must go all the way through the housing. The pin can only be installed in the CCW slots when the actuator is in the CW position. When the W7751H closes, the damper rotates CCW either 45 or 60 degrees to fully close.

3. If the damper rotates counterclockwise (CCW) to open, and the angle of the damper open to closed is 90 degrees, manually close the damper fully to the clockwise direction and mount the W7751H to the damper box and shaft. Tighten the Allen set screws. The part no. 201614 Range Stop Pin, which is shipped with the W7751H Smart VAV Actuator, is unnecessary. When the W7751H opens, the damper rotates CCW 90 degrees to fully open.

NOTE: Be aware that the damper is closed. Until the

W7751H is powered and the damper is driven open, starting the fan system with all the VAV box dampers closed can cause duct overpressurization and damage.

4. If the damper rotates counterclockwise (CCW) to open, and the angle of the damper open to closed is 45 or 60 degrees, see the following NOTE.

NOTE: Special precautions must be taken for this

application. Mount the W7751H to the damper box. (Do not tighten the Allen set screws yet). Before the part no. 201614 Range Stop Pin, which is shipped with the W7751H Smart VAV Actuator, can be inserted in either the 45 or 60

degree CW slot, the damper actuator must be driven fully open (CCW). To do this, the controller on the W7751H must be wired, powered, and connected to the portable PC via the Serial LonTalk

Adapter (SLTA). The SLTA connects to the controller on the W7751H via the jack for Network Access on T7770 Wall Module or by the B-Port on the Q7750A Zone Manager. From E-Vision Software, drive the actuator on the W7751H fully CCW, and insert the range stop pin in either the 45 or 60 degree CW slot, whichever applies (see Fig. 7). The range stop pin must go all the way through the housing. The pin can only be installed in the CW slots when the actuator is in the CCW position. (Disconnect the portable PC once programming has been completed.) Manually open the damper shaft fully (CCW) and then tighten the Allen set screws. When the W7751H closes, the damper will rotate CW 45 or 60 degrees to fully close.

RANGE STOP PIN

ACTUATOR PLATES

CCW

M10002

Fig. 7. Properly inserting range stop pin.

The Honeywell Software Tool’s (miscellaneous parameter for rotation direction) defaults to CW to Open, which applies to the damper direction and angle in items 1 and 2 above. The parameter must be changed to CCW to Open if the damper shaft rotates in this direction, which applies to the damper direction and angle in items 3 and 4 above.

IMPORTANT

It is advisable to leave the dampers in an open position after W7751H installation to avoid the possibility of overpressurizing the ductwork on fan startup. Use the De-clutch lever (see Fig. 2 for De-clutch lever location) to open the box damper on W7751H controllers that are powered down, to prevent overpressurization in the ductwork on fan startup. To use the De-clutch lever, press and hold the lever in the direction of the arrow (this disengages the motor). Turn the damper shaft until the damper is open and release the lever. When power is restored to the W7751H controller, the controller synchronizes the damper actuator so that the damper is in the correct position upon startup.

When a range stop pin is used with a field-added auxiliary switch, the tab on top of the range stop pin must point inward toward the VAV damper box shaft. See Fig. 11. This allows clearance for the auxiliary switch housing. To remove the pin, pry it up with a flathead screwdriver. See Fig. 8.

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