High-Temperature AC Motor for a Commercial Heater: Class H

What the heater OEM needed

A European OEM building commercial heating equipment needed a high-temperature AC motor. It had to drop straight into an existing appliance.

Their brief came with photographs of the existing motor and, more usefully, of where it sits. In the end that second set mattered most.

The photographs told the real story

The motor lives inside a densely insulated box. In other words it sits in the very heat the appliance is built to trap.

Typically that means forced-air unit heaters, convection ovens or large air curtains. In each, the motor sits in the hot zone rather than beside it.

The stated constraints

• First, a 220V, 50Hz single-phase supply.
• Second, a nominal 1500 RPM and roughly 3W output.
• Next, a drop-in fit: three M5 fixings on a 120mm flange, plus a 5mm shaft.
• Finally, CE and EAC marks, since the product sells into Europe and the Eurasian Economic Union.

Above all, one requirement went unstated. This high-temperature AC motor has to run for years under thermal stress, since a failure stops the whole appliance.

Building a high-temperature AC motor

We identified the motor type first. A shaded-pole AC induction motor is the usual choice for low-power, cost-sensitive HVAC duty.

Consequently the challenge was never electrical performance. Three watts is trivial. The challenge was thermal endurance.

Why not an EC motor

A brushless DC motor would be more efficient. However, we rejected it, and for good reasons.

At 3W the efficiency gain is worth almost nothing in absolute terms. Meanwhile an EC motor costs far more, and it needs a DC rail or a converter the appliance does not have. So for a high-volume OEM chasing reliability and cost control, the proven AC architecture was the shorter path.

Where the engineering actually went

Standard components fail early in this environment. Consequently we changed two of them.

• First, Class H insulation on the stator windings. That is rated to 180C, against the 130C of Class B or the 155C of Class F in ordinary motors.
• Second, a 626-series high-temperature ball bearing. We ruled out a plain sleeve bearing, since it cannot hold its oil film at steady high heat.

Together those choices address the two failure modes heat really causes: winding breakdown and bearing seizure. Meanwhile nothing else in the motor needed changing.

Ultimately the finished high-temperature AC motor met every size and electrical requirement, while carrying the thermal margin the job quietly demanded.

Technical Specifications

The insulation class below is the row that matters. Otherwise this is an ordinary small motor.

Parameter	Value
Model Number	LWSPM6112-05
Voltage	220 V
Frequency	50 Hz
Speed	1500 RPM
Output Power	3 W
Insulation Class	H (180°C)
Bearing	626 High Temperature Ball Bearing
Mounting Dimensions	Ø120mm flange, 3x M5 holes
Shaft Diameter	Ø5 mm
Certifications	CE, EAC
Net / Gross Weight (24 pcs)	10.5 kg / 12.5 kg

Technical Documentation

LWSPM6112-05 Engineering Drawing
The final engineering drawing for the LWSPM6112-05 provides all dimensional and electrical specifications for OEM integration and quality control.

A reference photo of the LWSPM6112-05 motor, showing the stator windings and cast-aluminum frame.

The motor installed in the customer’s final application, a high-temperature HVAC unit, demonstrating its intended operating environment.

The OEM bulk packaging label, detailing shipping information and confirming CE/EAC compliance for European and Eurasian markets.

Why the OEM sourced it here

For a high-temperature AC motor bought in volume, four things carry the decision.

• Premium parts, deliberately chosen. Class H insulation and a high-temperature bearing are not cheap components, and both are in this build. Producing the motor ourselves is what let the OEM raise reliability without that decision arriving as a cost shock.
• Room to change later. This was a straight replacement. However, any future change to shaft length or mounting would run through our 90-day NPI cycle, against the 12 to 18 months European makers typically quote.
• Certification handled. Their markets need CE and EAC. Our China-local TUV NORD Notified Body relationship shortens that considerably, which removes a bottleneck from their launch rather than ours.
• Consistency across thousands of units. Production certified to ISO 9001, 14001 and 45001 means every carton is built the same way. On a component this small, batch-to-batch variation is what causes field problems.

Browse our fan motor range, or the shaded pole motor section. Appliance safety follows IEC 60335-1.

Questions about this motor

What is the maximum operating temperature?

Here the high-temperature AC motor uses Class H insulation, rated to a continuous 180C. Together with the 626 high-temperature ball bearing, that suits continuous running in the elevated ambient found inside commercial heating appliances. Note this is the winding rating, not the ambient rating, so send us your enclosure temperature and we will check the margin.

Is it a direct replacement for other shaded-pole motors?

Yes, we build it as a form, fit and function replacement. It carries a 120mm flange with three M5 points and a 5mm shaft. Even so, check the 25mm total shaft length and 21mm extension against your impeller first. If they do not match, we customize shaft dimensions inside our 90-day NPI process.

Can I get a 60Hz or 120V version?

Yes. This model is specified at 220V/50Hz, though we build motor platforms for every global standard. A 110/120V, 60Hz variant needs an adjustment to the stator windings, which is routine work for us. Send your technical requirements to our sales engineers for a quote.

Why does a 3W motor need this much thermal engineering?

Because the heat is not coming from the motor. It comes from the appliance around it. A 3W motor generates almost nothing itself. However, sitting inside insulation designed to trap heat means it lives at an ambient that would destroy a standard build. In short, the power rating tells you nothing about the thermal problem here.

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