Modular Components - nvent 910 Series Installation, Operating And Maintenance Instructions

1.4 MODULAR COMPONENTS

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Ground Fault Alarm and Trip
Ground Fault (GF) current levels are monitored and may be displayed in milliamps.
The availability of the actual ground fault level gives the user the choice of both alarm and trip
levels suitable for the particular installation.
Overcurrent Protection
A unique overcurrent protection algorithm greatly reduces the possibility of damage to the
circuit or the controller in the event of a temporary overload while allowing for initially high
in-rush currents (SSR options only).
Soft Starting
Given the circuit breaker size, the 910 will limit the energy let-through to help prevent nuisance
breaker trips due to cable in-rush. This feature makes the controller particularly attractive for
use with self-regulating cables (SSR options only).
Minimum/Maximum Temperature Tracking
The controller maintains the minimum and maximum temperature values it has measured
since the last reset of these values. This is helpful in determining causes of temperature
alarms.
Latching/Non-Latching Temperature Alarms
User selectable non-latching temperature alarms allow the controller to automatically clear the
alarm when the condition no longer exists.
High and Low Voltage Alarms
Operating at voltages less than design can cause serious loss of heater output. The alarming
of preset voltage deviations ensures availability of sufficient wattage output.
Power-Limiting
The 910 will control the maximum output wattage if the full load power exceeds the specified
Maximum Power Setpoint. This feature eliminates the need for low voltage transformers in
many applications and can assist in standardization of heating cable types (SSR options only).
Autocycling
The controller will momentarily energize the circuit (for 10 seconds) at a programmable
interval. Circuit alarms will be generated at the time of autocycle instead of when the heat is
required. This feature eliminates the need for a preventive maintenance program as these tests
are performed at regular intervals by the controller.
Temperature Sensor Failure Alarm
Both open and shorted sensors are detected and alarmed by the controller.
Random Start
A startup delay between 0 and 9 seconds ensures that all units do not come on line at the
same time.
Full Digital Communications
An optional internal communications interface allows the communication of alarms
and analog data to a monitoring system. Industry-standard RS-232 or RS-485 serial
communications are available for applications requiring direct interfacing to other devices.
The modem version maintains compatibility with legacy products, including the Group
Communications Controller (Model 780/GCC-9000). With heat trace data at the user's
fingertips, historical trending of temperatures, power consumption, or other parameters are
available for analysis and system optimization.
CSA C/US
The 910 Series of controllers are approved for Class I, Division 2, Groups A, B, C, D hazardous
locations making them ideal for direct installation in the field. This may save the significant
expense of wiring back to a centrally located electrical distribution center.
The 910 Series controller is made up of two components. Each component's primary function
is described below.
1.4.1 CONTROL MODULE
The 910 Control Module forms the heart of a single heat trace control solution. Each Control
Module provides all of the intelligence required to control and monitor one heat trace circuit.