0191 5166636 enquiries@ht-uk.com

Many applications requiring a fixed temperature set point rely on mechanical thermostats for thermal control. But, thermostats are inadequate for many applications because of the long-term reliability issues such as 100,000 cycle rating and poor temperature control.

The SERIES EHG® thermal solution includes a compact precision temperature control, thermocouple sensor and power switching device integrated into the flexible heater's power cord. The SERIES EHG reduces system costs and substantially extends the life over conventional thermostat solutions.

The evolution of miniature microprocessor technology and Watlow switching technology fostered the development of a small versatile precision temperature control and thermocouple sensor that can be integrated with Watlow silicone rubber heater products. This device senses the temperature via input from a thermocouple strategically placed on the heater mat. The microprocessor is programmed prior to shipment with the customer's application specific set point. This results in quick delivery of a custom, integrated system.

The small mass of the thermocouple provides superior response to changes in process temperature and allows for higher watt density silicone rubber heater designs. Depending on the specific application, Watlow's power switching design can extend life up to 40 times greater than thermostats. These features result in an integrated custom set point temperature control product with superior life span, faster heat-up rates and improved accuracy. The SERIES EHG system has been tested to over four million cycles at rated amperage.


Material Maximum Operating Temperatures Maximum Watt Densities
°F °C W/in2 W/cm2
N/A  158 70 80 12.5
  • UL® recognized to 428°F (220°C) operating temperature
  • Voltage rating: 120 or 240VAC 0 30/+10%, 50/60Hz
  • Watt densities to 80 W/in² (12.5 W/cm²)
  • UL® recognized to 10A max


  • Semiconductor processing
  • Aerospace composite repair
  • Foodservice equipment
  • Freeze protection
  • Life sciences
  • Telecommunications

Features & Benefits:

Features Benefits
Process controller and safety limit in one package
  • Meets UL® 1998 and CE 60730 requirements
  • Eliminates the need for a thermal fuse on a heater
Optional display/communications module
  • Allows easy upgrade onto base device
  • Offers low cost field upgrade
Accurate and flexible temperature process controller
  • Replaces problematic bi-metal thermostats with accurate electronic temperature process controller
  • Allows easy change of process parameters
Ambient operating temperature range 32°F to 158°F (0°C to 70°C)
  • Increases reliability when mounting in harsh temperature environments or in close proximity to heaters
Integrated high/low temperature alert signal relay
  • Provides dry contact output to activate external alarm or process function
  • Signals control status with three integrated LEDs
Health check diagnostics
  • Monitors maximum heater process temperature, maximum ambient temperature and thermocouple operation
  • Provides health check signal to inform operator that the process is working correctly
Universal power supply
  • Allows an input of 85 to 264VAC, 50/60Hz
  • Provides safe control of up to 2400 watts with 10 amperes switching in both controller and safety limit
Can be switched from on-off and PID algorithm
  • Increases product life (on-off control is default)
  • Offers selectable PID control algorithm for tighter temperature uniformity