lenze americas articles

MCH Series MCH Controls Climate of Oyster Habitat

Lenze Americas 3/7/2018

MCH DriveAs a result of over-harvesting, environmental pollution and two new parasites, the famous native Chesapeake Bay oyster population has dramatically decreased.

In an attempt to bolster the population, the University of Maryland is conducting a study to assess the effects of introducing the Suminoe oyster, an Asian species that has shown to be resistant to the prevalent parasites. A University of Maryland extensive study examined the Suminoe oysters' eating and reefing habits as well as their vulnerability to the known native oyster predators.

Tests we were conducted at the University's Center for Environmental Science Aquaculture and Restoration Ecology Lab. This facility has the unique advantage of both a closed aquatic system as well as a secure, flow-through system plus experimental temperature and carbon dioxide controls for climate change research and a quarantine laboratory for the safe study of non-indigenous species.

Through their mechanical contractor, J.M. Zimmer, Inc., the University of Maryland chose Lenze Americas MCH variable frequency drive to control their pumps, cooling towers and building HVAC system. The MCH Inverter Features a Built-in PID Set-Point Controller Function as well as the automatic 3-contactor drive bypass, which assures full isolation of the VFD electronics and allows the motor to transfer from 'drive' operation and continue running across the line in 'bypass mode'.

"The advantage of the MCH 3-contactor bypass in strictly controlled testing laboratories," explains Joe Zimmer Jr. of J.M. Zimmer, "is an increase in reliability, making sure uninterrupted performance of the laboratory's entire HVAC system was maintained so research results are not compromised." Having the power and control wiring easily accessible and ample wiring space, the MCH is considered one of the simplest to install, set up and use of all the HVAC variable frequency drives on the market. A single-point connection makes the MCH drives less error-prone and easy to support.

Process systems often require a system controlled parameter, such as motor speed, to be able to react to variable situations in order to keep other system attributes constant, such as pressure, flow or temperature. Lenze Americas builds the set point controller function into the MCH drive to compare the set-point value to the actual value and generate a speed command to the drive to correct the variance or error.

MCH Series Benefits:

  • Automatic Transfer to Bypass Option
  • PID Setpoint Control
  • Program Controller: Direct or Reverse-Acting
  • Keypad Option for Local & Remote Operation
  • Simple to Install
  • Proven Performance & Reliability