Precision Electric: Online » MCH

AC Tech MCH Series Controls Climate of Oyster Habitat

Ryan Chamberlin — Fri, 12 Mar 2010 14:25:49 +0000

As 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 24-month study will examine the Suminoe oysters’ eating and reefing habits as well as their vulnerability to the known native oyster predators. The tests will be conducted at the University’s Center for Environmental Science Aquaculture and Restoration Ecology Lab. This new facility has the unique advantage of both 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 the Lenze – AC Tech MCH variable frequency drive to control their pumps, cooling towers and building HVAC system. The MCH drive 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 we maintain uninterrupted performance of the laboratory’s entire HVAC system, 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 – AC Tech 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

Heat Transfer Boxes & Systems: A Breeze with the AC Tech MCH Series

Ryan Chamberlin — Tue, 09 Mar 2010 14:30:32 +0000

Epsilon Industries is a supplier of integrated air and fluid side-heat transfer systems including factory built penthouses with mechanical/electrical systems; complete heat transfer packages and refrigeration systems. “One reason for the success of the ‘packaged’ mechanical systems concept,” says Epsilon Sales & Marketing VP, Brad Hughes, “is customers realize they can decrease the total cost and meet their deadlines by utilizing our specialized, highly trained technical staff.” To regulate pumps, chillers and air handlers, Epsilon uses MCH Series drives from Lenze – AC Tech.

What led Hughes to choose the MCH Series? “Our choice of variable frequency drives is a good example of how closely we look at anything that can be done better.” As he explains, “These Lenze – AC Tech drives offer a couple of advantages that make a lot of sense to us, one is the automatic transfer to bypass; the others are the disconnect option, and the on-site warranty.” The automatic-transfer-to-bypass option allows the motor to transfer from drive operation, and continue across the line in bypass mode.

Say there’s an external condition that creates a problem with variable frequency drive operation; like transient voltage harmonics from the utility causing the drive to trip off on a fault. The MCH drive can be configured to attempt several restarts, but if the condition will not clear, the automatic-transfer to-bypass function will transfer from drive operation to line power, without any human intervention. If the drive did not have this capability, an experienced, trained operator would have to be on hand to ascertain there was a problem, and then he would have to manually put the drive into bypass mode.

“Utilizing the MCH drive is a way for us to make sure we maintain uninterrupted service, no ifs or buts,” summarizes Hughes. Once again, dependability under demanding circumstances and assuring their customers that the systems are going to offer top performance is a crucial aspect of Epsilon’s market success. Epsilon has found a niche and is taking full advantage of it. Hughes counts on Lenze – AC Tech relating “Demystifying drives is the first step towards making them an integral part of our clients’ design. When we don’t need an expert to understand them, we can really count on them, and move on.”

MCH Series Benefits:

• Automatic Transfer to Bypass Option

• Automatic Disconnect Option

• Keypad Select for HOA (Hands Off/Auto)

• PID Setpoint Control

• Variable Torque Drive

• NEMA 12 Enclosure Available

• RS-485 MODBUS Communication

• Proven Performance & Reliability

Frequency Inverters: Improving AC Motors Productivity

Ryan Chamberlin — Fri, 26 Feb 2010 17:24:27 +0000

Variable frequency inverters are used for electronic speed control of AC induction motors. The needs of the market are wide and varied, and we offer a broad range of standard products for everything from simple speed control to complex; each with a wide range of functionality, small physical size and exceptional performance. Our drives are reliable, flexible to apply, easy to commission, and meet the highest standards of quality. Lenze-AC Tech provide solutions to fulfill nearly any inverter requirement in the power range between 0.25 and 400 kW.

SMV Standard Enclosure

NEMA 1 (IP31)
120V – 600V
0.33 to 30HP ( 0.25 – 22kW)
Open-loop Vector, V/Hz

Washdown Enclosure

NEMA 4X (IP65)
120V – 600V
0.33 to 30HP ( 0.25 – 22kW)
Open-loop Vector, V/Hz

Integral Disconnect

NEMA 4X (IP65)
Integral Motor & Drive Disconnect
0.33 to 10HP ( 0.25 – 7.5kW)
Open-loop Vector, V/Hz

MC Series

120-590V
00.25 to 150 Hp (0.18-110kW)
NEMA 1 (IP31), NEMA 4(X) (IP65), NEMA 12 (IP54)
V/Hz

MCH Series

200-590V
1.0 to 250 Hp (0.75-185kW)
NEMA 1 (IP31), NEMA 4(X) (IP65), NEMA 12 (IP54)
V/Hz

Lenze – AC Tech offers many other products including but not limited to servo drives, gearmotor drives, and more. To learn more about additional Lenze – AC Tech products please contact us.