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•
the controller failing with its heating output
constantly on
•
an external valve or contactor sticking in the
heating condition
•
the controller setpoint set too high.
Where damage or injury is possible, we recommend
fitting a separate over-temperature protection unit,
with an independent temperature sensor, which will
isolate the heating circuit.
Please note that the alarm relays within the
controller will not give protection under all failure
conditions.
Installation requirements for EMC
To ensure compliance with the European EMC
directive certain installation precautions are
necessary as follows:
•
For general guidance refer to Eurotherm
Controls EMC Installation Guide, HA025464.
•
When using relay outputs it may be necessary
to fit a filter suitable for suppressing the
emissions. The filter requirements will
depend on the type of load. For typical
applications we recommend Schaffner FN321
or FN612.
•
If the unit is used in table top equipment which
is plugged into a standard power socket, then
it is likely that compliance to the commercial
and light industrial emissions standard is
required. In this case to meet the conducted
emissions requirement, a suitable mains filter
should be installed. We recommend
Schaffner types FN321 and FN612.
Routing of wires
To minimise the pick-up of electrical noise, the low
voltage DC connections and the sensor input wiring
should be routed away from high-current power
cables. Where it is impractical to do this, use
shielded cables with the shield grounded at both
ends. In general keep cable lengths to a minimum.
