Nelson AXPC100-CM-GP Heat Tracer

July 7, 2021

The Nelson AXPC100-CM-GP and CM-GP microprocessor-based digital controllers are engineered to accurately control, monitor, and maintain the process temperatures of industrial pipes or tanks in ordinary (non-hazardous) locations. Ideal for replacing aging electro-mechanical thermostats, the controllers achieve cost savings by eliminating the need for several components with a design that integrates sensor monitoring, ground fault leakage detection, and remote alarm contacts into a single enclosure.


These environmentally hardened controllers are housed in a NEMA 4X fiberglass reinforced, UV resistant polymer enclosure resistant to rain, snow, hose-directed water, and windblown dust. Dual-pole heater switching adds to system versatility, making the controllers suitable for heater voltages from 120 to 277V AC. A broad temperature capability of 0 to 218°C (32 to 425°F) increases the range of process operations where they can be installed to deliver outstanding performance, safety, and energy efficiency.


While the Nelson CM-GP controller comes ready to wall-mount, the AXPC100-CM-GP is configured for direct installation on piping systems. As a stand-alone pipe-mounted solution, the AXPC100-CM-GP significantly reduces installation labor and material costs. It employs the field-proven Nelson AX Connection Kit for fast, simple pipe mounting.


As simple to operate as they are to install, both controllers feature a single line, alphanumeric LCD display that enables the use of English language prompts for set point entry and operation for one heat tracing circuit. LED lights indicate whether there is the power to the unit, if the heater power is on, along with the current status of alarms. Dry contacts close in the event of alarm activation, including high or low-temperature alarms, sensor failures or ground fault trips, and are conveniently wired to a terminal strip for local or remote use. Built-in ground fault leakage detection is a key advantage because it does away with the need for a separate EPD branch circuit breaker and costly manual maintenance checks.


Ground faults typically are the result of damaged or improperly installed heat tracing cables that allow current-carrying conductors, surfaces or parts to be in contact with grounded objects. This type of fault can eventually become serious, resulting in overheating, dangerous fires, and shock hazards.


As a standard feature, Nelson AXPC100-CM-GP and CM-GP controllers are programmed to trip when leakage current exceeds the specified maximum allowable amount. By installing the controllers, the end-user brings their heating circuit up to the current requirements for ground fault equipment protection outlined in the National Electrical Code and Canadian Electrical Code.


The Nelson Heat Trace Type AXPC100 CM GP is a micro-processor-based combination power connection and a digital electronic controller that has been specifically designed for stand-alone pipe-mounted electric heat tracing applications. This system provides temperature control of an individual heater segment with sensor monitoring, remote alarm contacts, and ground fault leakage detection.

  • The controller system is housed in a NEMA 4X Fiberglass reinforced, carbon impregnated, UV resistant polymer enclosure designed for wall-mounted applications
  • The system is provided with dual-pole heater switching and is environmentally hardened for use in various plant locations
  • The AXPC100 CM GP can be installed in ordinary locations
  • The system is provided with a common alarm contact for remote monitoring of the control system
Certifications and CompliancescCSAus Certified: Ordinary Locations
EnclosureNEMA Type 4X
MaterialFiberglass reinforced, carbon impregnated, UV resistant polymer
Ambient Temperature-40 to +140°F (-40 to + +60°C) ; Starting at -4°F (-20°C)
Temperature InputRange: +32 to +425°F (0 to +218°C)
Accuracy: ±1 °C
Repeatability: ±1 °C
RTD: 100-ohm platinum, 3 W, (sold separately)(lead compensated up to 20 ohms)
Heater SwitchingConfiguration: Two-pole, EMR.
Ratings: 100 to 277V AC, 30 Amp continuous (resistive load only).
Line Frequency: 50 or 60 Hz
Control PowerPower Requirement:
Control power from heater voltage, 110 to 277V AC, 12V A max
User InterfaceThe single-line, alphanumeric LCD display enables the use of English language prompts for setpoint entry and operation.
There are no cryptic codes or keypress combinations to remember.
Enclosure (H x W x D)6.5 x 6.5 x 4.0 IN., captive screw covers
Alarm OutputAlarm: EMR Form C.  
Alarm Rating:
EMR Version 24 to 277V AC @ 2.0 Amp Max, 12 to 30V DC
LED Indication
Alarm FunctionHigh-Temperature Alarm, Low-Temperature Alarm,
Sensor Failure, Ground Fault Trip