George's Creek Wastewater Treatment Plant - Allegany County, MD
PLC based control, instrumentation and SCADA system. The system included Modicon PLC's, Square D Motor Control Centers with (4) VFD’s on the aeration system, (4) VFD’s on the RAS/WAS system, (4) VFD’s on the filter influent system, and (2) soft starts on the filter backwash blower system. All VFD's were mounted in Square D Model 6 Motor Control Centers along with numerous full voltage starters. The plant is controlled by 5 Modicon Quantum processors networked together using a fiber optic and Ethernet network. The plant is monitored centrally in an operator control room using multiple computers running Wonderware InTouch and locally using Xycom Industrial Touchscreen PC's. The PLC program was developed using IEC compliant Concept software.
Town of Manchester SCADA Radio Upgrade - Carroll County, MD
The Town of Manchester has a radio based SCADA system utilizing SCADAPak PLC’s and spread spectrum radios. The existing radios were failing and constant nuisance alarms were occurring. Control panels at each of 18 locations were outfitted with new radios to send/receive data to a central location. Central HMI with InduSoft development software is used to monitor and control all remote sites. Several additional sites have been added to the SCADA system utilizing the same configuration.
City of Frederick SCADA System - Frederick County, MD
The City of Frederick utilized 900 MHz Phoenix Contact Spread Spectrum Ethernet radios with Modicon M-340 PLC’s to eliminate their leased line communications to each of their XX sites. Control panels at each site were designed and built by MTD and were outfit with the radio/PLC combination to send and receive data to a master site as well as pass data between the sites for a more enhanced control system. Some locations had existing PLC’s that were removed and replaced with the new PLC equipment whereas others were brand new installations. At the master receive site, the customer utilized Citect SCADA software to monitor and control all sites.
City of Frederick WWTP Chlorine Building MCC Upgrade - Frederick County, MD
Multiple projects have been completed for the City of Frederick. This project was a replacement of an existing motor control center and upgrade to the SCADA PLC. The MCC was a MTTM configuration with FVNR starters and VFD’s. Each of the units in the MCC was connected to the SCADA system via Ethernet. The FVNR starters all utilized TeSys T overload relays with Ethernet ports. The VFD’s and power monitors each contained an Ethernet port for communication to the SCADA system. The PLC was a Modicon M340 programmed with Unity software. An HMI was located in the MCC. The HMI was a Magelis IPC running a Citect client application.
Town of Denton SCADA System - Caroline County, MD
The Town of Denton SCADA system consists of multiple Well, Pump Station and Tank sites communicating to the master site at the WWTP – total of 12 . Each remote site has a PLC based control system with a local touchscreen Operator Interface. The remote sites communicate to the master via 900 MHz spread spectrum Cellnet series II/III/IV radios. The Master at the WWTP consists of multiple PLC’s networked by 10baseT and 100baseFL Ethernet communications. There is are two HMI’s running at the plant; one is a desktop PC, the other is a panel mounted industrial PC, both are running GE Proficy software.
Verizon Silver Spring Auto Transfer Scheme
The Verizon Silver Spring project entailed upgrading a Symax PLC system to a new Square D Premium PLC system. At this site, there are 13 breaker transfer pairs that each allow power to be fed from a utility or generator source to feed their respective loads. To power the generator bus, there are three diesel generators that had to be started, paralleled and closed onto the bus to provide emergency power via their own independent PLC systems. In addition to the breaker control, Load Shedding and Load Curtailment were two control schemes that were also implemented. MTD replaced a total of 4 PLC’s and all associated IO to bring the system up to current technology standards. Additionally, MTD Developed a Wonderware SCADA interface on two units – A PC that resides in the control room and a touchscreen mounted to the gear that allowed for operator control and monitoring.
Harford Community College SCADA System - Bel Air, MD
The Harford Community College WWTP SCADA system consists of 9 Remote sites and a Master (Polling) site that are monitored via a central location. The system utilizes Allen-Bradley MicroLogix 1500 PLC’s in conjunction with MDS Licensed Frequency radios to collect and monitor the data and alarms at the central location. The SCADA system was developed on the Allen-Bradley RSView32 for Machine Edition platform and was interfaced to MS Access for Data Logging and Reporting as well as Win911 for remote alarm dialing and notification.
East Point Sewage Pump Station - Baltimore County, MD
A complete renovation of an existing sewage pump station was performed by the general contractor. A motor control center, pump control panel, and instrumentation were provided by Micro-Tech Designs, Inc. The MCC contained VFD’s with SSRV bypass; the MCC was modified in our shop to meet the custom requirements of the control for the project. The PCP contained a primary and secondary PLC with Ethernet communications to redundant OIT’s. A dial-up modem was installed to interface to the county wide SCADA system. Field instruments included pressure rings with gauge and transmitter, submersible transmitters, backup high level tuning fork point level probes, circular chart recorders, magnetic flow meter, and vibration monitoring for the pumps. At the time of writing this MTD has completed 30+ pump stations for the county, ranging from 10 - 500Hp.