Smart Buildings Systems for Architects, Owners and Builders

Relay Panels

Relay panels are typically mounted next to the electrical circuit breaker panels.
The circuit breaker panel feeds into the relay panel with the relays in the relay
panel acting as a switching device for the circuit. Many relay panels can be
fed by both 120 V and 277 V circuit-breaker panels and relay groups can be fed
by different voltages in the same panel. Each relay can be individually
programmed through the system controller or the relay panel (Fig. 4.2).
Relay panels provide line voltage control of the lighting loads; they allow
for a single circuit to feed into several relays and for multiple circuit breaker
panels to feed into a single relay panel. While relay panels can be programmed
or controlled by a system controller, they can also operate without the system
controller. The relay panels typically have status indicators for the relay out-
puts, dry contact inputs for program override purposes, and inputs for moni-
toring devices, such as photo cells and occupancy sensors.

Lamps

Relay

Building

Circuits

Clock/

Timer

Occupancy

Sensor

Switch

Photoelectric

Sensor

Group Switch

Group Switch

Switch

Relay Panel

Control

Unit

Relay

Relay

Relay

Relay

Relay

Figure 4.2 Lighting control relay panel.

50 Smart Building Systems for Architects, Owners, and Builders