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.
Belt drive fan with vfd.
The integration of variable frequency drives in hvac units are becoming required by code.
And of course you need to know the input frequency of the motor and a few simple ratios.
Belt drives are often employed in cooling towers with lower horsepower requirements.
One uses a variable frequency drive and the other makes adjustments based on calculated sheave ratios.
Controlling fan speed on a belt driven fan.
With the growing acceptance and affordability of vfd motor controllers direct drive fans are increasingly finding their way into mainstream industrial fan applications.
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.
Not all motors will last with vfd drive.
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.
Belt driven is not a problem but you need to check the motors to see if they are compatible with vfd.
Well if your fan wheel is perfect at 1760 rpm it would ramp up great with a vfd.
With a belt driven fan there are two ways to control speed.
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.
Direct driven fans fans of all types have traditionally been driven by belts.
Because of the fewer parts involved they can often be more compact in design.
Qualitytime civil environmental 15 mar 16 18 02 vfd s need filters and line reactors to prevent harmonics backfeed onto the line side.
The programming of some vfd s are complex and can be overwhelming.
Integral controller or pairing a vfd variable frequency drive with a three phase motor.
Like a gear drive the belt drive does not require a variable frequency drive vfd.
On belt driven fan applications a vfd is also useful for simple speed changes.
Both an ecm and a vfd control motor speed by manipulating the frequency and voltage of electricity supplied to the.
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.
These motors will be labeled as either inverter ready or inverter rated depending upon the motor manufacturer.
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.
A vfd is a great solution when a flexible fan speed solution is required.
I suggest you understand its basic functionality but leave the programming to a skilled electrical worker.
Efficient synchronous motor technologies that always require vfd control such as permanent magnet and switched reluctance motors.
