Frequency inverters improve workplace comfort
A
Lenze product story
Edited by the Engineeringtalk editorial team
Aug 17, 2007
The SMV features a pluggable memory chip which allows the inverter to be set up in seconds, even on the bench before installation.
By fitting frequency inverters to air curtains in the loading bays of a major mail sorting centre, an employee comfort problem was solved and energy costs reduced at the same time.
The Lenze SMV, a new design of frequency inverter with IP65 enclosure, was fitted and proved particularly easy to install and use.
With a resulting 60% saving in energy costs, payback time on the investment was less than 12 months.
Air curtains are often used where doors must be frequently opened or left open.
A curtain of high velocity air, either heated or at room temperature, is blown across the door opening.
This causes a barrier to the natural convection in which cold air creeps in at ground level and warm air escapes near the top of the door.
Preventing the loss of warm air and the ingress of cold air saves energy for the building.
Doors can be left open for the duration of the loading process and the passage of personnel and trucks is not impeded.
This massive 160000m mail sorting centre runs seven days per week and 24 hours per day.
A total of 72 loading bay doors are in operation, fitted with hot air curtains to keep out cold winter weather.
It is estimated that each door is open with the air curtain running for 3600 hours per year.
The air curtains operate with a centrifugal fan fitted across the top of the door, blowing downwards and with dampeners to direct the flow.
Each is driven by a 5.5kW four-pole motor.
The required flow is dictated by the size of the opening and external conditions such as the wind velocity.
In practice these motors were oversized to cope with the worst case conditions plus a safety factor - a common situation with pump and fan drives.
The result in this case was a blast of high velocity air that seems to bounce from the floor with turbulence, and permitting a noticeable ingress of cold air at ground level.
Furthermore the air blast was stirring up dust.
The workers employed near the doors were unhappy and in some cases turned the air curtains off.
An investigation by the plant management established the cause of the problem to be the velocity of the air curtain, and decided that fitting variable speed drives was a potential solution.
Three loading bays were to be tested.
On-site electrical and maintenance teams were used for the installation.
The teams were trained in the products and the necessary skills to fit them safely, and the resulting acquisition of skills was viewed positively by the personnel involved.
The inverters fitted were the new model SMV from Lenze, a vector drive with an IP65 enclosure so that does not require an enclosure.
A RFI filter is integrated into the inverter, and the SMV features a pluggable memory chip which allows the inverter to be set up in seconds, even on the bench before installation.
It is simple to operate with a keypad and display on the front face.
The Engineers at the sorting centre found the installation without a panel to be easy, and were able to set it to run whenever the door is open.
With an outside temperature below zero, it was found that the temperature in the air surrounding the retrofitted doors rose from 18 to 25C.
The new temperature was too high, allowing the air curtains to be turned down.
The motor speed was reduced in steps to find the optimum according to the local conditions around the bay doors.
Generally a 30% speed reduction to 35Hz was found to be possible, giving comfortable working conditions and cutting electricity consumption by 60%.
The motor power factor improved by 34%.
In practice the energy saving was even greater as the amount of heat taken from the plant's heated water system was also reduced.
To quote the Electrical Manager of the sorting centre, "Retrofitting a variable speed drive to an existing air curtain is simple, viable and an energy saving application that enhances the comfort and performance of employees".
Not what you're looking for? Search the site.
Contact Lenze
Tel +44 1234 321200
Other Lenze stories
-
ETP Hyloc bush is based on hydromechanics
Lenze is offering the ETP Hyloc bush, based on hydromechanical principles, for the assembly and disassembly of hubs to shafts. -
Screw jacks for mid- and high-force linear motion
Techdrives has released a range of heavy-duty screw jacks with rated forces from 5 to 350kN; new models of up to 700kN will come on-stream in 2010. -
Hexaflex-Blue couplings extend drivetrain lives
Techdrives has introduced the Hexaflex-Blue range of shaft couplings for marine applications. -
Lenze motors operate reliably in harsh conditions
Lenze has developed a three-level system of surface and corrosion protection that ensures reliable operation of geared motors in high humidity, atmospheric contamination or outdoor installations. -
Lenze releases modular I/O system 1000
Lenze's new I/O system 1000 combines extensive functionality with a modular mechanical concept and compact design.
Browse by category
-
Capital Equipment (3,533)
- Capital Equipment (1)
- Compressors and Air Treatment (546)
- Electrical hardware (131)
- Electronics Manufacturing, Tools, Instruments (192)
- Machinery and Production Equipment (1,133)
- Manufacturing Machinery and Plant Equipment (478)
- Production line blowers and fans (74)
- Robotics, Handling and Storage (978)
- Consultancy and Services (927)
-
Control and Instrumentation (5,142)
- Cabling, Conduit, Signal Conditioning (818)
- CNC and Motion Controllers (190)
- Control and Instrumentation (3)
- HMIs/Operator Interfaces (297)
- Logic Controllers, Timers and Relays (96)
- Mid-range and Large PLCs (204)
- Plant- and Machine-Wide Communications (1,210)
- Plantwide control (1,354)
- Power Supplies, Uninterruptible Power (577)
- Smaller-Sized PLCs (393)
-
Drives, Motors and Controls (3,451)
- Drives, Motors and Controls (2)
- Industrial Drives/Controls (1,293)
- Industrial Motors (502)
- Linear Drives and Motors (121)
- Precision Motors and Gears (434)
- Stepper and Servo Drives, Motors, Controls (1,097)
-
Electrical and Electronic Equipment Design (4,328)
- Batteries, chargers and circuit protection (588)
- Connectors, Terminals, Busbars, Slip Rings (724)
- Electrical and Electronic Components (653)
- Electrical and Electronic Equipment Design (4)
- Electrical and Electronic Subassemblies (377)
- Enclosures and Equipment Cooling Fans (722)
- Knobs, Handles and Enclosure Hardware (430)
- PCs and Embedded Systems (830)
-
Engineering Design Software (6,388)
- 2D CAD software (203)
- 3D CAD software (1,199)
- CAM, CNC, production management software (583)
- Data, document management software (324)
- Electrical design software (168)
- Engineering Design Software (17)
- FEA and structural analysis software (377)
- File conversion software, data capture (358)
- Fluid, thermal, noise, vibration software (340)
- Materials design and moulding design software (153)
- Maths, charting, statistics, QA software (325)
- PLM and collaboration software (665)
- Process, instrumentation, automation software (269)
- Publishing and documentation software (234)
- Rendering, visualisation, styling software (208)
- Simulation, modelling, validation software (965)
-
Engineering Industry News, Resources (6,199)
- Electronic Resources for Engineers (273)
- Engineering Business News, Views (388)
- Engineering Conferences (438)
- Engineering Education, Resources, Standards (851)
- Engineering Exhibitions, Events (578)
- Engineering Guides, Newsletters (354)
- Engineering Industry Developments, Awards (635)
- Engineering Industry News, Resources (4)
- Engineering Industry Reports, Surveys (597)
- Engineering Recruitment, Employment (219)
- Engineering Seminars (421)
- Engineering Training Courses (458)
- Health and Safety Consultancy, Software (180)
- Health and Safety Events, Training, News (285)
- Health and Safety Legislation (403)
- Health and Safety Strategy, Risk Assessment (115)
- Machine Building (4,633)
-
Materials and Processing (3,041)
- Materials and components (2,272)
- Materials and Processing (5)
- Materials processing and testing (292)
- Rapid Prototyping (472)
-
Monitoring, Measurement and Quality (5,682)
- Data Acquisition Hardware and PC I/O Boards (491)
- Data acquisition Software and Communications (505)
- Data loggers (428)
- Electrical and Electronic Testing, PAT Equipment (645)
- Form/co-ordinate, optical, vision instruments (766)
- Gauges, Indicators and Instruments (449)
- Materials testing equipment (439)
- Monitoring, Measurement and Quality (1)
- Telecomms/network test equipment, software etc (159)
- Testing and Calibration Services and Information (522)
- Testing, analysing and monitoring equipment (1,277)
-
Powertrain Design (3,723)
- Bearings (986)
- Chains and belts (334)
- Gears, brakes, couplings and engines (1,482)
- Hydraulic Components (475)
- Lubricants (441)
- Powertrain Design (4)
-
Sensors (7,324)
- Accelerometers and Vibration Sensors (450)
- Barcode Sensors (103)
- Flowmeters and Flow Sensors (650)
- Gas, Chemical, Radiation, Magnetic Sensors (292)
- Humidity and Environmental Sensors (158)
- Level Sensors and Leak Detectors (539)
- Linear Position Sensors (418)
- Loadcells, Force Sensors, Torque Sensors (733)
- Pressure sensors (644)
- Proximity Sensors (715)
- Rotary Position, Tilt and Angular Sensors (567)
- Sensors (12)
- Temperature sensors (626)
- Vision and Colour Sensors (1,417)
- Small Mechanical Components, Joining, Tools (2,059)
- Valves, Pumps, Process Hardware (3,732)
