NGC-20 INSTALLATION MANUAL
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2.5 Communication and networking
The DigiTrace NGC-20 controller is equipped with a RS485 interface. Through this
interface up to 247 DigiTrace NGC-20 units can be networked to a DigiTrace NGC-UIT or
to one serial port of standard PC running Pentair Thermal Management´ Windows based
DigiTrace Supervisor software.
The DigiTrace NGC-UIT can be placed indoors (DigiTrace NGC-UIT-ORD-E) or outdoors
(DigiTrace NGC-UIT-OUT-E) in non hazardous areas. DigiTrace supervisory software
allows DigiTrace NGC-20 units to be monitored or programmed from any location due
to the client-server architecture. Please refer to the datasheet and operating manual of
the individual products for more information (DigiTrace NGC-UIT-ORD: INSTALL-112;
DigiTrace Supervisor: INSTALL-117).
2.6 Configuration
The DigiTrace NGC-20 controllers can be configured locally by means of a handheld
programming device (DigiTrace NGC-CMA) or from a central location using the DigiTrace
NGC-UIT or DigiTrace Supervisor Software. After programming, all settings are
permanently stored in the nonvolatile memory of the DigiTrace NGC-20 control unit,
avoiding loss of data
in the event of power failure or after a long term power shutdown.
3. mAInTEnAnCE
Equipment placed into hazardous areas needs to comply with EN 60079-17 regarding
inspection and maintenance requirements. The EN 60079-17 describes in more detail the
requirements regarding documentation, qualifications of personnel, inspections, regular
periodic inspections, continuous supervision by skilled persons, maintenance, isolation of
apparatus, earthing and inspection schedules.
4. sAFETy InsTRuCTIons FoR DIGITRACE nGC-20-Cl-E
4.1 safety function of temperature limiter in DigiTrace nGC-20-Cl-E
The application areas for (safety) temperature limiters can be found anywhere where
there are thermal processes to be monitored, and where the system must be set to
a safe operating condition in the event of a fault. If the permitted temperature limit
(Temperature classification) is reached, or a fault occurs within the normal operating
temperature (probe break/short-circuit, component defect, power failure), then the
instrument switches to the safe state without delay. If the fault is no longer present,
then the safety temperature limiter must be manually reset. This can be done either by
means of the internal reset button inside the unit, The DigiTrace Supervisory Software or
the handheld programming device. The unit will only accept to be reset after the normal
operating conditions have returned.
4.2 Area of use
Safety temperature limiters are required in all areas where thermal processes need to
be prevented from overheating. In case of a temperature upset they will put the system
into a safe operating condition. The safety function will invoke in the event of a fault,
when the permissible temperature limit is reached or in case a fault occurs (such as
probe break, probe short-circuit, component failure, or supply failure) even when the
process conditions are within the permissible temperature range. In all these cases
the equipment is immediately switched off. If the fault is no longer present, than the
safety temperature function must be manually reset before the unit goes back to normal
operation. DigiTrace NGC-20-CL-E units can be reset by means of an internal push button
or via dedicated software. The output of the unit will only be enabled when all conditions
are safe; meaning that the temperature measured by the limiter RTD has dropped below
the limiter set point and when there are no other faults being detected. In other words,
the unit will only reset after the normal operating conditions have returned.
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