Overview
The MWS1A series of microwave presence detector
switches are designed to provide automatic control of
lighting, heating or ventilation loads. The MWS1A detects
movement using a highly sensitive microwave detector.
This works by emitting low power microwave signals and
measuring the reflections as the signals bounce of moving
objects. The MWS1A is optimised for wall mounting
applications to give detection over long distances.
When movement is detected the load is turned on. When
an area is no longer occupied the load will switch off after
an adjustable time out period.
The internal light sensor provides additional energy saving
in lighting applications. When an area is occupied lighting is
only switched on when the level of natural light is below a
preset level.
Three variants are available
MWS1A-PRM Mains voltage, switched live contact
MWS1A-PRM-VFC Mains voltage, isolated changeover
contact
MWS1A-PRM-LV Low voltage, isolated changeover
contact
Features
Microwave Sensor
Detects movement within the unit’s detection range,
allowing load control in response to changes in occupancy.
IR Receiver
Receives control and programming commands from an IR
(infrared) handset.
Light Level Sensor
An integral adjustable photocell allows the lights to be kept
off if there is sufficient ambient light.
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.
Status LED
The LED flashes Red to indicate the following:
Fig 1: Front features
Walk Test LED active
when movement is detected
Valid setting received
Microwave Presence Detector - wall mounted
MWS1A-PRM
Product Guide
Sensor Lens
which covers...
IR Receiver
Light Level Sensor
Status LED
Mounting screw covers
2
Installation
BS4662 square
back box
DIN standard round
back box
To switch from more than one position simply wire two or more units in parallel to achieve two way and intermediate
switching.
The detector should be sited so that the occupants of the room fall inside the detection pattern shown overleaf, at a
recommended height of 1.2m to 1.5m for wall sensors. Note that the higher the sensor is installed the shorter the
detection range will be.
Do not site within 1m of any lighting or ventilation equipment.
Do not fix to a vibrating surface.
Site as far away as possible from the surface of metal objects.
Back box Compatibility Mounting
The MWS1A is designed to fit both UK and EU style
backboxes.
Wiring
25mm
Do not over tighten
Mounting screw cover
MWS1A-PRM
MWS1A-PRM-VFC MWS1A-PRM-LV
N N L/OUT
L
Neutral
Circuit protection
(if required)
Load
Neutral
Live out
Live
+
NC
-
NC
NO
COM
NO
+
Neutral
Circuit protection
(if required)
NC
NO
Live
Fault finding
What if the load does not turn ON?
Check to see if the live supply to the circuit is good. For the MWS1A-PRM version only: strap across the L and
LIVE OUT terminal to turn the load on.
If the supply and wiring are good, check the LUX level setting. Increase the LUX level setting to allow the
controller to turn on at higher ambient natural light level.
What if the load does not turn OFF?
Ensure that the area is left unoccupied for a greater time period than the time out period set using the switch.
Make sure that the sensor is not adjacent to vibrating surfaces or objects (e.g. ventilation equipment).
The unit may pick up movement through thin partitions or walls. Reduce the sensitivity.
N
L
NC
COM
NO
Loading...