Monthly Archives: December 2013

M-RL: Machine-Room Less Elevator

MRL

The machine-room-less elevator is the result of technological advancements that often allow a significant reduction in the size of the electric motors used with traction equipment.  These newly designed permanent magnet motors (PMM) allow the manufacturers to locate the machines in the hoistway overhead, thus eliminating the need for a machine room over the hoistway. This design has been utilized outside the USA for at least 15 years and is becoming the standard product for low to low-mid rise buildings. It was first introduced to the U.S. market by KONE. Product acceptance was initially slow in the U.S. market because of its initial, limited applications, its inability to meet U.S. code requirements, and the limited number of manufacturers offering an equivalent product.

In the past few years,  elevator manufacturers have overcome the obstacles to acceptance of the MRL product.  All of the other elevator manufacturers are now marketing their versions of the MRL, and the product offering has been expanded to include many of the more popular elevator sizes and speeds.  In addition, local code officials have become more receptive to the technology; most are now allowing the equipment to be installed in their respective jurisdictional areas, at least on a case by case basis.

Benefits of MRL elevators:

• The use of the MRL elevator will save a significant amount of energy (estimated at 70-80%) as compared to hydraulic elevators. The power feeders for the MRL are also significantly reduced due to the more efficient design and the counter-balancing provided with traction equipment.

•  The MRL elevator eliminates the cost and environmental concerns associated with a buried hydraulic cylinder filled with hydraulic oil.  Over the years hydraulic elevators have come under greater scrutiny relative to environmental concerns due to the buried hydraulic cylinder.  Because the MRL elevator is a traction elevator with all its components above ground, this is not a concern for this equipment.

• The MRL elevator utilizes a gearless traction type machine, which results in superior performance and ride quality compared with hydraulic elevators.  MRL’s can also operate at faster speeds thus increasing the perception of quality over a conventional hydraulic elevator.

For more information about Machine-Room Less ELevators, please give our office a call!

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Are Your Elevator Doors Not Closing Properly?

Shaft

As the weather continues to get cold and windy, many building owners and managers experience issues with their elevator doors not closing properly. These issues are directly associated with an increase in wind this time of year. Elevator hoistways are very similar to wind tunnels, and constant airflow creates a large amount of pressure in these shafts. The only escape for this air pressure is when the hoistway doors open and close. As the doors open and close, air pressure rushes in and out. Many times, this prevents the doors from closing, which then prevents proper latching of the interlocks and keeps contacts from matching up. This results in a broken safety circuit and failure of the elevator system and operation.

How does this happen? The existing reel-closure system in hositway doors has a coiled up spring encased with a hub in the middle and a cable butt ended to the casing. When the door is open, the spring is wound up to it’s tightest point, and the tension is at it’s highest. When the door closes, the spring torque decreases, as so does the cable tension.  Clearly more tension is needed when the doors close.

These issues with hoistway doors not closing is one of the most common phone calls we receive at the office. Here at Pride and Service, our goal is to make sure that we solve all of our customers elevator issues, and provide a solution that will prevent these problems from happening in the future. With that in mind, we now have access to technology that will allow hoistway doors to close properly regardless of the wind pressure. This new product is a re-designed reel closure which will replace all of the closers on each floor on all of your elevators.

Have you experienced issues with your hoistway doors not closing properly? Are you interested in learning more about this product? We would be happy to answer all of your questions, and help you make sure that all of your elevators are functioning at 100%.