7kw PTC Coolant Heater

 

 

 

 

At ambient temperature, the PTC ceramic element has low resistance and heats up rapidly upon energization. When the temperature reaches the Curie point, the PTC resistance rises sharply, automatically limiting the heating power to achieve self-regulation and preventing continuous overheating. Heat is transferred via the metal substrate to the coolant in the internal flow channels, which is then circulated throughout the vehicle's thermal management loop by an electric water pump. The unit features an integrated controller that supports CAN bus communication with the vehicle's VCU/BMS, allowing for dynamic adjustment of output power.

 

 

Item	W09-1	W09-2
Heating output	5kw, 6kw, 7kw, 8kw @10L/min,T_in=60℃
Rated voltage(VDC)	350V	600V
Working voltage(VDC)	250-450	450-750
Impulse current(A)	≤40@450V	≤25@750V
Controller low voltage(VDC)	9-16 or 16-32	9-16 or 16-32
Control signal	CAN2.0B,LIN2.1	CAN2.0B,LIN2.1
Control model	Gear (5th gear) or PWM	Gear (5th gear) or PWM
Heater dimension	258.6*200*56mm
Heater weight	＜2.7kg
High voltage connector in heater	Amphenol HVC2P28MV104
High voltage connector in car	Amphenol HVC2P28FS104
Low voltage connectors	320Q60A1-LVC-4 (Haichen A02-ECC), & Sumitomo 6189-1083

 

 

 

 

 

 

 

 

Advantages over other heat sources

Compared to waste heat from internal combustion engines: It does not rely on engine operation, ensuring a stable heating source even when the engine of a hybrid vehicle is shut off; for pure electric vehicles (which lack an engine), PTC serves as a traditional heating solution.

Compared to heat pumps: Heat pump heating performance degrades significantly in extremely low temperatures, whereas PTC is unaffected by low ambient temperatures and provides stable heating, often serving as a low-temperature auxiliary heat source for heat pumps.

Compared to standard resistance wire heaters: Resistance wires are prone to burnout and overheating (posing a fire risk), while PTC features self-limiting temperature capabilities, offering greater safety redundancy.

 

 

 

 

Battery Electric Commercial Vehicles (Primary Use Cases)

Electric buses, electric heavy-duty trucks, sanitation vehicles, port terminal tractors, and electric dump trucks. Applications include cabin heating and windshield defrosting/demisting in winter, as well as preheating and thermal management of traction batteries in low-temperature environments. The high-power 7kW output is designed to accommodate spacious cabins and large-capacity battery packs.

Plug-in Hybrid (PHEV) Commercial Vehicles / Large PHEVs

When the engine is shut off and no waste heat is available, PTC heaters are used to provide cabin heating and battery preheating. While small-to-medium passenger vehicles typically utilize 3–5kW units, the 7kW specification is reserved for large hybrid commercial vehicles.

 

 

The PTC high-voltage hydronic heater utilizes PTC ceramic heating elements and integrates high-voltage drive circuitry with CAN communication control, offering features such as self-limiting temperature, rapid heating, and high safety and reliability. It generates heat for new energy vehicles via coolant heat exchange and is primarily used for low-temperature preheating of traction batteries, cabin heating, and windshield defrosting in electric commercial vehicles, fuel cell vehicles, and specialty electric vehicles. The unit contains no rotating parts, offers excellent vibration resistance, supports multi-level power adjustment, and is compatible with 350V/800V vehicle high-voltage architectures.

 

 

 

 

 

After installation and power-up, the heater fails to operate; what are the first three points to check?

① Check if the 12V low-voltage power supply is normal and if the connectors are securely locked;
② Check if the VCU/BMS has issued enable and power request signals;
③ Check if the vehicle's high-voltage circuit is closed and if there is coolant flow. The heater operates only upon receiving a command; it does not automatically begin heating upon startup.

 

 Under what conditions will the heater automatically reduce power or shut down completely?

① Excessive inlet coolant temperature;
② Heater unit overheating;
③ Insufficient coolant flow;
④ High-voltage level outside the operating range;
⑤ Insulation fault;
⑥ Loss of CAN communication; BMS thermal management restriction commands. These are standard protection logic responses and do not necessarily indicate component damage.

 

What are the requirements for the coolant? Can different types of antifreeze be mixed?
 

You must use the ethylene glycol coolant specified for the vehicle; mixing antifreeze products with different formulas or brands is prohibited. Mixing can cause sediment formation, clogging heater channels, reducing flow, and triggering overheat protection; it can also corrode internal aluminum waterways, leading to slow leaks.

 

Does the heater housing require a ground connection? What are the consequences of a poor ground connection?
 

The housing must be reliably connected to the vehicle chassis ground. Poor grounding can lead to false insulation fault alarms during high-voltage insulation monitoring; furthermore, if internal insulation degrades, the protection circuit may fail to trigger, creating a safety hazard.

 

Can an 800V platform PTC coolant heater be installed directly onto a 400V vehicle?
 

They are not directly interchangeable. The voltage withstand ratings of the PTC ceramic chips differ. If an 800V heater is used in a 400V system, heating power drops significantly, resulting in poor heating performance; conversely, installing a 400V heater in an 800V vehicle will cause immediate PTC breakdown, component burnout, and insulation failure. Always verify the part number against the platform voltage.

 

 

 

 

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