Grayson Thermal Systems has unveiled a new generation of high-voltage PTC (Positive Temperature Coefficient) electric water heaters engineered specifically for heavy-duty electrified applications. The EW series (EW3, EW4, and EW5) represents a significant advancement in auxiliary heating solutions for both electric and hydrogen fuel cell powertrains operating in thermal-critical environments.

Technical Specifications and Architecture

The expanded product range delivers precisely calibrated thermal outputs across multiple voltage platforms:

• EW3 operates at 800V DC with 7kW output capacity, optimized for integration with next-generation high-voltage electrical architectures
• EW4 delivers 10kW at 800V DC, providing sufficient thermal capacity for large platforms facing extreme ambient temperature challenges
• EW5 generates 5kW at 350V DC, targeted for mid-sized powertrain thermal management in conventional EV voltage systems

All units employ advanced PTC semiconductor elements that provide inherent self-regulation characteristics, automatically modulating power consumption in response to temperature conditions without requiring additional control circuitry. This fundamental property creates an inverse relationship between element temperature and electrical resistance, preventing thermal runaway scenarios.

Control Systems and Integration

The heating modules feature comprehensive CAN-bus communication architecture for seamless integration with vehicle management systems. Real-time diagnostic capability continuously monitors critical parameters including:

• Input voltage verification
• Current draw analysis
• Internal temperature mapping
• Flow rate confirmation
• Element status monitoring

Over-temperature protection mechanisms employ redundant safeguards with both software and hardware cutoffs to maintain thermal stability under all operating conditions.

Application Engineering

These thermal management solutions have been specifically developed for deployment across multiple heavy-duty electrified platforms including electric and hydrogen fuel cell buses, commercial vehicles, off-highway equipment, defense applications, and stationary power systems.

Matthew Hateley, Head of European Sales and Marketing at Grayson, explained: “The EW series represents a comprehensive thermal management solution rather than simply a heating element. These are fully-integrated high-voltage thermal modules engineered to support the industry’s transition toward elevated voltage architectures prevalent across our target sectors.”

The modular design philosophy enables flexible integration across diverse platforms while maintaining consistent thermal performance metrics. This engineering approach is the result of Grayson’s 47 years of thermal system expertise in mission-critical applications worldwide.

Each unit has undergone rigorous validation testing to ensure reliable operation in extreme temperature environments, supporting the specific thermal requirements of next-generation electric vehicle batteries and hydrogen fuel cell systems.

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