Problem-Solver, Series 8
The HVAC maintenance department was losing its cool over the continuous problems with a large number of air
conditioning fan drives at a NASA facility in Alabama.
There are many critical areas within this complex where the environment must be closely controlled.
It seemed as through the maintenance dispatch telephone was constantly ringing.
The electrical load centers were not wired for the tremendous in-rush current drawn by these high inertia fans.
Even though the drive motors were originally installed for WYE/DELTA electrical starting, there still was rapid
deterioration of the silver on the electrical contacts. The v-belt drives would literally smoke on start-up and the
belt screeching was intolerable.
Our Rexnord District Sales Office was contacted and a joint sales call was setup with one of our stocking
distributors to help find a solution to these frustrating problems.
Current Problems
The high starting requirements of the fan were greater than the motor’s capabilities.
The motor stays in the low rpm range because the pull-up torque is not sufficient to accelerate the load.
Repeated starting cycles severely overheat the drive motors, reducing their expected service lives.
Bell slippage upon starting was burning up v-belts almost as fast as they could be replaced.
The True Torque Solution
Now the motor only has to start the relatively small WK2 of the True Torque fluid coupling Instead of the fan.
This allows the motor to quickly accelerate to its breakdown torque, thereby increasing its starting capability.
True Torque fluid couplings allow the motor to start virtually unloaded, preventing damaging heat build-up of consecutive starts.
True Torque fluid couplings will provide a soft, cushioned start by gradually applying torque to the system,
thereby eliminating belt slippage and maximizing drive component life.
Implementation
The customer purchased seven True Torque fluid couplings for the air conditioning fan drives at their complex.
All were installed by March 21, 1985, ready far the next cooling season. The drives have been starting quietly and
smoothly ever since. Smoking, squealing v-belts are a thing of the past. Drive motors and switchgear temperatures
have dropped drastically from what they had been. Rapid deterioration of the electrical contacts has been
eliminated as the Falk fluid couplings allow the motors to accelerate quickly under virtually no load.
Let us show you how to keep from losing your cool!
CONTACT YOUR REXNORD FLUID COUPLING DISTRIBUTOR FOR THE SOLUTIONS TO YOUR POWER TRANSMISSION PROBLEMS.
Form 860901
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