Improved Design for VFD Enclosures

How innovative VFD enclosure design is helping to manage heat.

VFD enclosure heat  is typically managed through tried and tested means such as forced ventilation, moving heat sinks to the exterior (through back panel) or other means such as air conditioning. Each of these are viable solutions, though environmental and operational considerations may impact suitability. But are they the only means of cooling? Could a better enclosure design assist with VFD cooling, creating a better installed system? The answer is yes.

Why be concerned with VFD enclosure heat?

Poor heat management in VFD enclosures shortens the life of drive and other electronic components. It can also lead to performance and stability problems. Other heat sources such as environmental, solar, or surrounding process can add even greater stress. This is particularly true for drives installed in outdoor areas. A 10⁰C rise in operating temperature reduces component life by 50%. The effects of heat can not only be seen in VFD performance, but in supporting devices within the enclosure, such as power supplies.

New VFD systems should incorporate best practice and better design

As stated earlier, there are many known practices in place to help improve thermal management of VFD enclosures, particularly for existing systems. New systems may warrant a fresh look. Enclosure manufacturers are designing enclosures specifically for VFD applications, incorporating many best practices and innovative features to manage heat and increase reliability. Special materials, finishes, shapes, and other innovations provide better cooling and can even simplify VFD panel construction.

The most innovative VFD enclosure design?

When planning for a new drive system or installation, we recommend the Hoffman Weatherflo enclosure. The design features many enhancements that improve thermal management.

• A white polyester powder finish with low solar absorption reduces the solar heat load 55-70 percent.
• An integrated solar shield top and intake cover provide an additional 25 percent solar reduction. Fan design is modular and scalable, providing for adjustment based on actual heat load.

A really innovative design element is the back panel loading feature. The back panel can be assembled and loaded from the rear of the enclosure. The enclosure can simply be placed over top the back panel and bolted down, making assembly much easier. No need to lift a heavy back panel.

Other enhancements include:

1. Active cooling ventilation system with factory-installed fan and filter (115 VAC)
2. Fan and vent placement optimizes heat removal by drawing ambient air into the bottom of the enclosure and exhausting at the top, making the entire enclosure an air duct
3. Multiple enclosure sizes with airflow designed for nominal horsepower ratings
4. Adjustable thermostat
5. Easy access washable expanded metal filter