Module F - Slide 4


Pre-installation, the technician who will be installing the APS should conduct an inspection and check to make sure that the conditions at the intersection match the conditions that were expected in the installation design. Specifically, the existing wiring should be checked to confirm that concurs with the specifications of the installation design. In addition, new users/installers should review all instructions. Sometimes an APS can be wired in such a way that it seems to work to the uninformed installer, but is providing incorrect or inappropriate information.

Example: An APS was installed so that the vibrator was wired to the WALK indication wires. When the technician tested it after installation, it gave a rapid tick sound (due to the vibrating arrow) for the WALK indication, when it was actually supposed to give a speech message. Unless someone had realized that the design called for a speech WALK indication, the device would have continued to operate in a way that was contrary to its design (rapid tick instead of speech message).

Setting up the APS equipment first in the shop is the best way that other technicians have found to get familiar with the devices and the wiring and adjustment procedures. Technicians are encouraged to consult the manufacturer with questions about the APS installation. Note that some distributors are not equipped with the necessary information or experience to adequately address installation problems. It’s been suggested that the technician take the phone number of the manufacturer with them to the APS installation site. It is often useful for a manufacturer to talk a technician through problems at the site.