Tunnel Master® wbc Installation Guide
Page 27
De-Selecting a Selective Relay Wiring
The reason for turning off a selective function on a wash is if a customer requests this. A customer
requesting to disable the tire shine for their wash is an example. Typically, the tire shine is a selective
option.
To de-select the selective relay, the selective function or relay needs to turn off. This is accomplished
by adding another relay.
These instructions explain how to wire and set up a second relay in series with the original selective
relay to disable a selective function in the Tunnel Master® wbc.
Adding a Second Relay
Adding a second relay in the series with the first relay. Relays are typically wired with two wires
going to the equipment, one wire being run from the equipment to Normally Open (NO) and the
second from the equipment going to Common (C). These are terminated in the terminal strip on the
left side of each relay board. See Figure 18.
See Tunnel Master® wbc User Manual to learn how to program the relay to function correctly, and
create a service to use the new retract.
Figure 20. Normal Wiring for a Relay
In the new configuration, move the wire going to the Common (C) to the second relay. After the wire is
moved, add a separate wire between the original relay and the new one that was added and terminate
at Normally Closed (NC) on the new relay. The new wire runs and terminates in the original relay on
Common (C). See Figure 20.
Figure 21. Adding a Second Relay in Series
