OCM III

© 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.
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© 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.
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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.
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© 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
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Siemens FI 01 · 2012