IntroductIon
The CMa20 is an M-Bus communicating temperature and humidity
sensor for outdoor use.
For a complete description of the product or for information in Swedish,
visit the Elvaco AB website, www.elvaco.com.
overvIew
CM
a
20
Outdoor M-Bus temperature and humidity sensor
1. Service
connector
2. M-Bus in
3. M-Bus out
4. Sensor pipe
5. Wiring lead-
through
6. Wall mounting
mountIng
Mount the product in a weatherproof location to avoid that direct
sunlight or rain affects the sensors. The product should be mounted
straight vertically and horizontally with the sensor pipe (4) downwards.
Use the holes (6) when mounting on wall.
m-Bus 2-wIre Bus
M-Bus is a multi-drop 2-wire bus with no polarity. Use a cable of area
0.25-1.5 mm
2
, e.g. a standard telephone cable (EKKX 2x2x0.5 mm).
Connect the incoming wiring to the screw connector (2) and use the
screw connector (3) for further M-Bus 2-wire bus connection.
ImPortAnt
•
All connected M-Bus slave devices must have unique M-Bus
secondary or primary addresses depending on addressing mode.
•
Measure voltage over M-Bus slave connection to verify M-Bus
master connection. Voltage should be between 21-42 VDC.
reset to fActory defAult
Reset to factory default by issuing the M-Bus command “Application
reset”, see CMa20 Users Manual.
trouBleshootIng
Product does not respond to m-Bus master commands
Please verify your M-Bus slave configuration and connection:
•
Voltage over M-Bus connection should be between 21-42 VDC.
•
All M-Bus slaves connected to the M-Bus master must have
unique primary or secondary addresses depending on which
addressing mode is used.
•
Verify M-Bus slave baud rate used by M-Bus master. M-Bus
master baud rate must be identical to the M-Bus slave baud rate.
temperature value is inaccurate
The temperature sensor is very accurate, but incorrect positioning of
the product may result in unintended temperature variations. Please
take the following in consideration when mounting the product:
•
Do not mount the product close to heat sources (front and rear).
•
Do not mount the product in direct sunlight.
sAfety
The warranty does not cover damage to the product caused by usage
in any other way than described in this manual. Elvaco AB can not be
liable for personal injury or property damage caused by usage in any
other way than described in this manual.
