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Relay Scanners

RELAY SCANNERS switch a Group of Relays when signaled by a Standard Douglas 2-Wire Switch or other Type of Input.

Douglas Relay Scanners

Relay scanners permit a large group of relays to be switched by a single device or by a signal from an automation device.

Individual & Group Control

Relays connected to a scanner can also be switched individually by connecting a standard Douglas 2-wire switch directly to the relay. This useful feature gives the occupants control of their individual space and permits an automatic lighting control device to control all of the lights.

Sequential Switching

Relay scanner outputs do not switch the relays all at once. Instead, they fire in a sequence that takes no longer than 4 seconds. The sequence is necessary for 2 reasons:

  1. A large amount of power is being switched. Instead of jolting all the power ON and OFF at once, the sequence "ramps" the power ON and OFF.
  2. The low voltage, Class 2-rated circuit has current limitations in the interest of safety. Sequencing the relay control power ensures that the Class 2 limits are not exceeded.

Non-Programmable Relay Scanners

Non-programmable relay scanners are intended for simple lighting control applications that require all of the connected relays to be controlled by only 1 group control device. There are 2 models of non-programmable relay scanners: WR-8812 (12 Outputs) and WR-8824 (24 Outputs).

Both models have 2 inputs. One of the inputs is compatible with Douglas 2-wire switches and the other is compatible with 24VAC contact control. Actuating either input causes all of the connected relays to switch ON or OFF.

Programmable Relay Scanners

The WRS-2224 Programmable Relay Scanner has 24 outputs and 5 inputs. The inputs are configurable to respond to Douglas 2-wire switches or to 24VAC contact control (Default is the 2-wire switch option).

Each input of the programmable scanner can be programmed with the buttons built into the scanner to control any or all of the relay outputs. If an input is configured for the Douglas 2-wire LED switch, the input will provide the correct group status indication to the connected switch.

Programmable Relay Scanners and Networks

The WRS-2224 Programmable Relay Scanner is a member of the
W-2000 System. A Douglas WNX-2624 Network Node can be plugged into the WRS-2224 Scanner to permit it to be networked with other scanners located in the same or in other panels.