© Siemens AG 2011 Level Measurement Continuous level measurement — Open channel flow — Ultrasonic controller OCM III ■ Overview ■ Benefits • Influent and effluent monitor • BS 3680 calculations provide exceptional accuracy in measuring flow • 1 to 24 months data log, subject to logging rate • RS-232 serial communication • High accuracy on unique or non-standard weirs and flumes • AC and DC operation. Automatically switches to battery operation for uninterrupted power • Dual power input • Low power remote monitoring • Flow Reporter software available for remote monitoring, configuration and data retrieval ■ Application The OCM III is a high accuracy ultrasonic flow monitor for open channels. In addition to monitoring flowrate in sewage works, OCM III can monitor industrial discharge, rainfall/storm water studies, inflow/infiltration studies and sewer system evaluations. As well as being compatible with many standard weirs and flumes, the programmable head versus flow curve (up to 16 points) accurately defines flow rate on unique or non-standard weirs and flumes. The OCM III has data logging and is adjustable from once per minute to once a day. It records the average flow rate for that time period. Daily, it records minimum/maximum of temperature and flow rates, and the time they occurred, as well as the daily total. Advanced functions include variable rate logging. It can be pre-programmed to log at a higher rate when needed. Under steady conditions, the OCM III automatically logs less frequently to conserve data log space. The OCM III has two-way communication via RS-232 with a modem or a bi-polar current loop with a current-to-voltage communication converter. Data logs can be downloaded to a file that can be manipulated into a spreadsheet or ASCII format. Siemens FI 01 · 2012 5/337 5 © Siemens AG 2011 Level Measurement Continuous level measurement — Open channel flow — Ultrasonic controller OCM III ■ Technical specifications Certificates and approvals 0.3 … 1.2 m (1 … 4 ft) or 0.6 … 3 m (2 … 10 ft) CE, FM, CSAUS/C, MCERTS, C-TICK2) Communication RS-232 or ± 20 mA bipolar current loop, 300, 600, 1200, 2400, 4800, 9600, 19200 baud Transducer Echomax XRS-5, 44 kHz Options Relays 3 alarm/control relays, 1 SPDT Form C contact per relay, rated 5 A at 250 V AC non-inductive or 30 V DC Mode of Operation Measuring range1) Output mA output • Max. load 0/4 … 20 mA, isolated • Resolution 5 uA • Isolation 300 V AC continuous 1 KΩ max. load +24 V DC, 20 mA average to 200 mA at 1/10 duty cycle max. 0 … 20 Accuracy Error in measurement ±1 mm/m, calculated error less than 0.02% Resolution 0.2 mm (0.007") Rated operating conditions Installation conditions • Location Indoor/outdoor • Installation category II • Pollution degree 4 Ambient conditions • Ambient temperature (enclosure) -20 … +50 °C (-5 … +122 °F) Design Weight 2.3 kg (5.1 lbs) Material (enclosure) Polycarbonate Degree of protection (enclosure) IP65/Type 4X/NEMA 4X Cable Transducer and mA output signal • Transducer: co-axial to be RG62-A/U low capacity • mA output signal to be 2 copper conductors, twisted, with foil shield/drain wire, 300 V 0.5 … 0.75 mm² (22 … 18 AWG) • Relay/power to be copper conductors per local requirements to meet 250 V 5 A contact rating Max. separation between transducer and transceiver 183 m (600 ft) Displays and controls LCD 5 x 7 dot matrix display with 2 lines of 40 characters each Programming Via removable programmer and communication link Memory 3 V battery (NEDA 5003LC or equivalent), operating life 1 year, SuperCap capacitor for back-up during battery replacement Power supply AC version 100/115/200/230 V AC ± 15%, 50/60 Hz, 20 VA max. DC version 9 … 30 V DC, 8 W max. 5/338 TS-2 Flow Reporter, a Windows-based configuration software and data extractor Velocity sensor input Input range: 0 … 10 V DC Resolution: 2.7 mV 1) 2) • DC output 5 Temperature sensor Remote monitoring Siemens FI 01 · 2012 Program range is defined as the empty distance to the face of the transducer plus any range extension EMC performance available upon request Windows is a registered trademark of Microsoft Corporation © Siemens AG 2011 Level Measurement Continuous level measurement — Open channel flow — Ultrasonic controller OCM III Selection and Ordering data OCM III High accuracy ultrasonic flow monitor for open channels. Input voltage AC, voltage selector switch Enclosure Wall mount, standard enclosure Wall mount, 6 entries, M20 holes1) Approvals CSAUS/C, FM, CE (EN61326), C-TICK CE2) 1) Available with approval option 6 only 2) Available with enclosure option B only C) Subject to export regulations AL: N, ECCN: EAR99. Order No. C) 7ML1002- 7A7 07 Order No. Selection and Ordering data Further designs Please add "-Z" to Order No. and specify Order code(s). Operating Instructions 0 A B 5 6 English C) 7ML1998-5AB01 French C) 7ML1998-1AB11 Spanish C) 7ML1998-1AB21 German Note: The Operating Instructions should be ordered as a separate line item on the order. C) 7ML1998-1AB31 This device is shipped with the Siemens Milltronics manual CD containing the complete ATEX Quick Start and Operating Instructions library. Required equipment TS-2 Temperature Sensor C) 7ML1812-1AA1 TS-2, 1 m cable C) 7ML1812-2AA1 TS-2, 5 m cable C) 7ML1812-3AA1 TS-2, 10 m cable C) 7ML1812-4AA1 TS-2, 30 m cable C) 7ML1812-5AA1 TS-2, 50 m cable C) 7ML1812-6AA1 TS-2, 70 m cable C) 7ML1812-7AA1 TS-2, 90 m cable C) 7ML1998- TS-2 Operating Instructions Note: The TS-2 Operating Instructions should be ordered as a separate line item on the order. C) 7ML1812-1AA1 5EW01 Accessories Handheld programmer 7ML1830-2AA Tag, stainless steel, 12 x 45 mm (0.47 x 1.77"), one text line, suitable for enclosure 7ML1930-1AC M20 cable gland kit (6 M20 cable glands, 6 M20 nuts, 3 stop plugs) 7ML1830-1GM M20 cable gland kit (4 M20 cable glands, 4 M20 nuts, 4 washers) 7ML1930-1FV Flow Reporter software license B) 7ML1930-1AK Flow Reporter Kit (includes disk, authorization code and cable) B) 7ML1930-1AL Spare parts Card, Mother, main C) 7ML1830-1MG Card, daughter/display C) 7ML1830-1LT Eprom C) 7ML1830-1KW Battery C) 7ML1830-1JV OCM III Lid overlay 7ML1830-1KV B) Subject to export regulations AL: N, ECCN: EAR99S. C) Subject to export regulations AL: N, ECCN: EAR99. Siemens FI 01 · 2012 5/339 5 © Siemens AG 2011 Level Measurement Continuous level measurement — Open channel flow — Ultrasonic controller OCM III ■ Dimensional drawings 209 (8.2) 172 (6.8) 106 (4.2) 91 (3.6) Lid screws (6 places) 267 (10.5) 285 (11.2) 16 (0.6) Programmer 5 Lid Suitable location for conduit entrances. Siemens Milltronics recommends using a punch for making holes in enclosure. Enclosure Mounting holes (accessed under lid) 4.3 mm (0.17") dia. / 4 places Customer mounting screw OCM III, dimensions in mm (inch) Transducer Current O/P Bipolar I/O RS-232 I/O 16 17 18 19 20 + + Vel Aux Input Input 0-10 V Temp. Sensor 21 P24V 15 SYNC 14 COM 13 SHLD – 12 WHT + 11 BLK – 10 RXD + 9 COM 8 TXD 7 TX – 6 TX + 5 SHLD 4 RX 3 SHLD 2 SHLD Hot 1 RX ■ Schematics 22 23 24 + – 25 26 27 28 29 30 31 32 34 35 36 L2/N L1 9-30 V P 24 V Output Input max. load Power average 20 mA Pulse 200 mA 1/10 duty 33 RL1 RL2 RL3 Position SW1 for 100/115/ 200/230 V AC operation (50/60 Hz, 20 VA) Notes: 1. Use RG62-A/U coaxial (or equivalent) for extensions up to 183 m (600 ft). Run in grounded metal conduit, separate from other wiring. 2. Each relay has 1 set of form 'C' (SPDT) contacts, relay rated at 5 A, 250 V AC, non-inductive, when equal or lower rated limiting fuses are installed. Relay de-energized when in alarm conditions and energized for pump control. OCM III connections 5/340 Siemens FI 01 · 2012