Carel uAD, User Manual, Page: 25 / 44

7
Fig. 2.a
Fig. 2.b
Fig. 2.c
Vista inferiore
Lower view
μ A D
Mode
μ A D
M
o d
e
GND
GND
Rx/Tx+
Rx/Tx+
Rx/Tx-
Rx/Tx-
G0
G
GND T+ T-
GND
+
GND
+
GND
+
24 Vac
120
Ω
µC 2 o µC 2 SE.
MCH2004850
ENGL
ISH
µAD +030220465 - rel. 1.1 - 15.12.2010
2.1 Instructions for mounting
Attention:
• Isolate the power supply before any installation or maintenance intervention on the µAD.
• The terminal must be fi xed to a wall to allow re-circulation of the air through the slots on the rear shell.
Avoid places where the environmental temperature can alter, for example, outside walls, in the vicinity of
doors leading to the outside or exposed to the sun.
The temperature and humidity sensors are very sensitive and are calibrated for air re-circulation in normal
environments: if this should be missing or if the air fl ow is excessively intense, the precision of the measu-
rement could be jeopardised.
Warning:
• Remove the power supply before intervening on the µAD in the mounting, maintenance and replacement
phase.
• Use precautions against electrostatic discharges when handling the board. Do not touch the electronic
components mounted on the board.
Information:
• Do not install in environments that have the following features:
• Relative humidity outside of the declared limits;
• Strong vibrations or blows;
• Exposure to jets of water;
• Exposure to aggressive and polluting atmospheres (e.g. sulphuric and ammoniacal gases, saline mists,
fumes) with consequent corrosion and/or oxidation;
• High magnetic and/or radio frequency interference (e.g. near to transmitter aerials;
• Exposure to direct solar radiation and atmospheric agents in general;
• Large and quick environmental temperature fl uctuations;
• Environments where explosive gases or mixtures of infl ammable gases are present;
• Exposure to dust (formation of a corrosive fi lm with possible oxidisation and reduction of isolation).
Mounting:
The distance of the mounting holes has been studied in order to fi x the µAD to a 503E built-in box in
compliance with CEI C.431 - IEC 670 Standards. If this is not present, use the mounting holes on the
shell as a guide for drilling the wall and then used the supplied screws and plugs.
The connection cables must pass through the hole present in the centre of the rear shell of the
µAD and must be fi xed to the clamps on the shell itself.
To access the connection clamps it is necessary to release the rear shell by levering the relative tab (see
fi g. 2.a). Opening and closing of the µAD must take place by applying a “hinge” movement, pivoting on
the upper side of the tool and lifting the lower side (see Fig. 2.a).
In the closing phase pay attention that the pins on the board are inserted into the corresponding clamps
and that the cables do not obstruct the operation.
2.2 RS485 data line connections
Warning:
• The network connections must be carried out exclusively by a qualifi ed electrician.
• The RS485 serial network line can only be connected to SELV circuits.
• RS485 network: use a shielded twisted pair with AWG20-22 type wire section. The maximum length of
the cables must not exceed1000 m. The capacity between the wires must not exceed 90pF/m.
• Separate the µAD cables from the cables that feed inductive and power loads in order to prevent
possible electro-magnetic interference. Never introduce power and serial communication cables into
the same channels (including those of the electric cables). Do not install the communication cables in
the immediate vicinity of power devices (contactors, magnet-circuit breaker devices or other).
Information:
• Use tag boards that are suitable for the clamps in use.
Network connections:
To make the µAD network connections, proceed as follows:
• introduce the cables inside the rear shell through the central hole;
• install the tag board onto the mains cable;
• connect the cable to clamps TX+, TX- (pair) and protect the shield to the GN
D clamp (fi g. b2);
• connect a 120
Ω
termination resistance to the end of the line opposite to the µAD.
2 INSTALLATION