CP Electronics MWS3A-PRM-2CHC, 2CHL - Manual (Page 2)

page 2
The MWS3A-PRM-2CH (microwave) detector provides automatic control of lighting loads with optional
manual control. It can be used on incandescent, fluorescent and compact fluorescent lighting, and has the
added benefit of being able to connect an external switch. The MWS3A-PRM-2CH detects movement
using a highly sensitive microwave detector. This works by emitting low power microwave signals and
measuring the reflections as the signals bounce off moving objects. The MWS3A-PRM-2CH has a unique
adjustable sensor head that allows the area of detection to be optimised for the application.
The MWS3A-PRM-2CH detector provides two independently controlled output channels that can be used
for a variety of applications:

Occupancy of two independent lighting circuits using a single detector—
e.g. for essential and non-essential supplies (part no. -2CHC) .

Occupancy and lux control of one lighting circuit and just occupancy control of a second circuit—
e.g. where a row of luminaries by a window is lux controlled whilst inner rows are switched on
occupancy only (part no. -2CHL) .

Occupancy and lux control of a lighting circuit and just occupancy control of a ventilation circuit
(part no. -2CHL) .

Occupancy on both lighting circuits, with separate lux control on each circuit (part no. -2CHL). The
DD-LCDHS must be used for setting up lux switching levels on the second circuit.
Please Note:
When controlling two circuits, the circuits must be on the same phase.
Two modes of operation are available:
Presence detection:
When movement is detected the load will automatically turn on. When the area is no longer occupied the
load will automatically switch off after an adjustable time period. If an external switch is connected, this
can override the lights off (after the detection time period has elapsed it will revert to automatic operation).
An integral adjustable photocell allows the lights to be kept off if there is sufficient ambient light.
Absence detection:
The load is manually switched on using an external switch. When the area is no longer occupied the load
will automatically switch off after the adjustable time period has elapsed. Pressing the switch again during
occupancy override the lights off (after the detection time period has elapsed it will revert to automatic
operation).
In both modes of operation a short button press turns the load on whilst a long button press turns the load
off.
An integral infra-red sensor in the unit allows the unit to be programmed using the optional DD-LCDHS
programming handset. This gives complete flexibility over many of the operating parameters. Without the
handset, manual adjustments can be made to the sensitivity, time settings and Channel 1 ―Lux Hold Off‖
using the controls on the side of the sensor housing.
On the ―LUX‖ versions, using the DD-LCDHS programming handset, as well as setting the above
mentioned parameters (sensitivity, time settings and Channel 1 ―Lux Hold Off‖), the adjustable internal
light sensor can also be programmed to switch the lighting off with one or both outputs during occupancy if
the level of light exceeds a second preset level. It can also be used to set the Channel 2 ―Lux Hold Off‖ if
required.
In addition a variant of the product provides a normally closed contact for fail safe operation (/NC). If the
unit fails, the outputs will default to on.
When the unit is first powered up the microwave sensor will always detect immediately regardless of
whether the room is occupied.
The UHS user handset can also be used to change lux levels and override the lights on or off.
2. Description and Operation