Installation Instructions
VLCA-1688
© Honeywell Page 1 LTBT-VLCA-INST Rev. A
Overview
Warning! Thoroughly read all instructions before mounting and
wiring. Install equipment in accordance with the National Electric
Code, the instructions, and in a manner acceptable to the local
authority having jurisdiction. Failure to do so can result in bodily
injury or equipment damage.
The VLCA-1688 (Advanced VisualLogic Controller) is a BACnet-
compliant unitary controller with 16 universal inputs, 8 binary
outputs, and 8 analog outputs.
These instructions are intended to help you mount and wire the
module and to perform configuration steps that can only be done
at the module. For additional setup and configuration instructions,
see the VLC Installation and Operation Guide (LTBT-TM-
GEN4VLC).
Fig. 1 VLCA-1688 dimensions
Mounting
The VLCA-1688 can be mounted on a DIN rail or on a wall. Mount
it indoors.
DIN rail mounting
• To mount the VLCA-1688 on a DIN rail
1Hold the module with its top tilted toward the DIN rail and
then hook the two top tabs on the back of the controller
onto the top of the DIN rail.
2Push down and in to snap the two bottom flex
connectors onto the DIN rail.
To remove it, push straight up from the bottom to release the top
tabs and then rotate the top of the controller outward.
Wall mounting
To mount the VLCA-1688 on a wall, position the module in any
orientation and secure it to the wall with standard machine or
sheet metal screws. Leave room on each side for connecting
wires.
Wiring
Once the VLCA-1688 is mounted, connect the wires.
Connecting Ethernet
Connect a standard Ethernet cable to the VLCA-1688 RJ-45 jack.
It automatically operates at either 10 or 100 Mbps based on the
capabilities of the Ethernet hub or switch to which it is connected.
Connecting MS/TP
Connect the VLCA-1688 to the BACnet system over an MS/TP
LAN that uses the EIA–485 signaling standard. Use shielded,
twisted-pair cabling with characteristic impedance between 100
and 130Ω. Distributed capacitance between conductors must be
less than 30 pF/foot (100 pF/m). Distributed capacitance between
conductor and shield must be less than 60 pF/foot (200 pF/m).
Foil or braided shield acceptable.
Connecting I/Os
The VLCA-1688 has 13 terminal blocks for wiring inputs and
outputs (see page 2). Twisted pair 18AWG shielded cable is
recommended to reduce electrical interference (noise). A single-
point grounding scheme that uses the transformer or panel
ground is optimum. Ground only one end of the shield drain wire.
The VLCA-1688 uses removable terminal blocks to simplify field
wiring of power and cabling. To make wiring easier, you can
remove the terminal blocks from the unit, connect the wires, and
then re-seat the blocks. Terminal blocks also make unit
replacement easier.
• To connect wires to a terminal block
1Strip a maximum of 3/8” (10 mm) of the wire jacket from
the end of the wire.
2Use a small screwdriver (1/8'' max.) to turn the
adjustment screw fully counter-clockwise.
The clamps in the wire slot separate as you turn the
screw.
3Insert the stripped end of the wire into the slot so that the
insulation end is flush with the terminal block. Be sure all
wire strands are in the slot.
4Hold the wire in place and turn the adjustment screw
clockwise until the clamps in the wire slot secure the
wire.
5Tug gently on the wire to check that it is secure.
Connecting power
Connect the VLCA-1688 to 24VAC power from a UL Listed Class
2 24VAC transformer (not provided). VLCA-1688 uses a half-
wave rectifier.
CAUTION! Half-wave devices and full-wave devices must not use
the same AC transformer. If the VLCA-1688 will share its power
supply with another device, make sure that the other device uses
a half-wave rectifier. Maintain wiring polarity.
Configuration
Setting the MAC address
Set the MAC address using the DIP switch see page 2.
For additional configuration instructions, see the VLC Installation
and Operation Guide (LTBT-TM-GEN4VLC).
7.1"
[18.04cm]
9.06"
[23.01cm]
1.5" [3.82cm]
