Operating instructions
cod. 1592001300
1592001300 XC440C gb r1.0 07.06.2004.doc
rel. 1.0
Page
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15. Electrical connections
The controller is provided with screw terminal blocks for wires having section not bigger than
2.5 mm
2
:
Check power supply data before connection wires.
Keep the probe and the digital input wires separate from the power cable.
Do not exceed the maximum rating current for each relay, check technical data and if the load
is bigger, use filtered contactors.
Before connecting cables make sure the power supply complies with the instrument’s
requirements. Separate the input connection cables from the power supply cables, from the
outputs and the power connections. Do not exceed the maximum current allowed on each
relay, in case of heavier loads use a suitable external relay.
15.1 Probes connection
Pressure probe (4 - 20 mA): respect the polarity. If using terminal ends be sure there are no
bear parts which could cause short circuiting or introduce noise disturbance at high
frequencies. To minimise the induced disturbances use shielded cables with the shield
connected to earth.
Temperature probe: it is recommended to place the temperature probe away from direct air
streams to correctly measure the temperature.
16. RS485 serial link
All models can be integrated into the monitoring and alarm system XJ500 using the TTL serial
port. They use the standard ModBus RTU protocol, so they can be fitted in a system integrator
using this protocol.
The controller has 2 serial addresses first one Ad1 for compressor section, second one
Ad2 for fan section. To completely monitor both sections the values of the 2 addresses
have to be different.
If the Ad2 parameters have the same value the status of the fans is not monitored.
