Efficient synchronous motor technologies that always require vfd control such as permanent magnet and switched reluctance motors.
Belt drive fan with vfd.
A vfd is a great solution when a flexible fan speed solution is required.
Because of the fewer parts involved they can often be more compact in design.
Today most standard nema premium efficiency motors are designed with characteristics that enable use with vfd s on variable torque loads such as the majority of fan applications.
Controlling fan speed on a belt driven fan.
And of course you need to know the input frequency of the motor and a few simple ratios.
Costs by eliminating belt transmissions further cost reduction due to lower inrush current.
Direct driven fans fans of all types have traditionally been driven by belts.
In the absence of a vfd simple sheave ratio modifications should do the trick.
With a belt driven fan there are two ways to control speed.
Not all motors will last with vfd drive.
The programming of some vfd s are complex and can be overwhelming.
A high inertia impeller fan can be started with a vfd using a much smaller motor than would be otherwise required to start the same fan across the line.
Plug plenum fans can end up high rpm the plenum cabinet you install them inside would get a couple few feet longer with direct drive.
Direct drive fans typically work better when you are trying to vary the speed of the fan with a vfd variable frequency drive or a potentiometer rheostat variable speed controller.
The integration of variable frequency drives in hvac units are becoming required by code.
While both belt and direct drive fans have been around for a long time the mainstay fan for most industrial fan applications under 250 hp has been the belt drive fan.
Integral controller or pairing a vfd variable frequency drive with a three phase motor.
Both an ecm and a vfd control motor speed by manipulating the frequency and voltage of electricity supplied to the.
Belt drives are often employed in cooling towers with lower horsepower requirements.
These motors will be labeled as either inverter ready or inverter rated depending upon the motor manufacturer.
Belt drive allows you to be much more compact on the big equipment not going to have a direct drive 15 horse blower motor spider mounted to a fan scroll.
One uses a variable frequency drive and the other makes adjustments based on calculated sheave ratios.
I suggest you understand its basic functionality but leave the programming to a skilled electrical worker.
The marley geareducer gear drive offers a more efficient alternative that provides energy installation and maintenance cost savings.
Belt driven is not a problem but you need to check the motors to see if they are compatible with vfd.
With the growing acceptance and affordability of vfd motor controllers direct drive fans are increasingly finding their way into mainstream industrial fan applications.
Like a gear drive the belt drive does not require a variable frequency drive vfd.