Checking rotation

Problem: You have installed a new ventilation blower and forgotten to check it for rotation. You can't easily get visual access. Solution: Don't hold a strip of tissue near the duct outlet.
By Staff September 1, 1999

Problem: You have installed a new ventilation blower and forgotten to check it for rotation. You can’t easily get visual access.

Solution: Don’t hold a strip of tissue near the duct outlet. You’ll be misled because a centrifugal blower moves air in the forward direction even when it’s rotating backwards. Instead, use your clamp-on ammeter. A blower turning the wrong way draws only a fraction of its rated current.

Contributor: Martin Green, Benchmark Testware, Winnipeg, MB; 204-774-4932