This resource area is to answer all your questions on SEM3T.
Siemens Thermal Monitoring System (SEM3T) is a modular monitoring solution for thermal monitoring, real-time data, alarming notifications, historical logging/ trending, and reporting.
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- 24VDC control power source is required.
- Specification: UL Listed 24V DC Class II power supply, Overvoltage (UL 61010), pollution degree 3 (UL 61010)
Each controller can support a maximum of 45 sensors.
Depending upon how thermal modules are required per controller. For example, if you need 45 thermal sensors are needed per controller, you will require 2 x 21 Position racks and 1 x 3 position rack.
- The standard cable length is 10 ft, and the maximum extension is up to 50 ft.
- Wire Type: UL rated operating temperature to 200 deg C, 600V rated, UL style 1199, 18AWG, 10 x 30 stranded
• Low Voltage Switchgear
- Power Connector (Where Horizontal Bus connects to Vertical Bus)
- Lug Pads (Incoming and Load)
• Switchboard
- Splice Plate (connection bus between multiple sections)
- Lug Pads (Incoming and Load)
- Cable insulation (Cylindrical Ring Terminal sensor)
• P4 and P5 power panels
- Cable insulation (Cylindrical Ring Terminal sensor)
Low Voltage Switchgear
- Located in the front auxiliary compartment, can be accessed by opening the auxiliary compartment door.
Switchboard
- Located in the main or distribution front auxiliary compartment, can be accessed by opening the auxiliary compartment door.
P4 and P5 power panels
- Located in the front auxiliary compartment, can be accessed by opening the auxiliary compartment door.
Refer to ‘Sensor Schedule’ in the equipment as-built drawing package.
Refer to ‘GA – Physical arrangement of SEM3T’ in the equipment as-built drawing package.
Yes.
Yes.
- Controller Operating Temperature Range = -10°C to +65°C / 14°F to 149°F
- Controller Humidity = Maximum relative humidity 80% for temperature up to 31°C decreasing linearly to 50% relative humidity at 40°C
- Sensor Operating Temperature range = 0°C to 130°C / 32°F to 266°F
- Altitude up to 3000 meters
- Pollution Degree 3
40°C to 105°C (± 2°C) / 104°F to 221°F (± 4°F)
Yes, but not with unshielded neutral sensor wiring.
Yes, provided Siemens’s installation instructions are followed.
Sensors can be relocated in the field, and it doesn’t void the factory warranty provided they are not damaged as part of the relocation process.
The sensor technology is using patented technology. The sensor electronics convert contact heat information received through the sensor metal terminal into electrical signals, interpreted as temperature data within the SEM3T Module.
We do not use optocouplers. Electrical isolation is provided in the sensors from the 600VAC to the low voltage side using the patented methodology.
We have used an external lab for extended Reliability testing to calculate the MTBF value. SEM3T system withstands up to 25 years based on an operating temperature of 40 °C or lower. We completed the HALT (Highly accelerated life testing) portion of the product family test, and we found no issues.
Non-Siemens Ethernet cables can be used to connect the SEM3T controller Modbus TCP communications to an external system (computer, supervisory system, etc..). Shielded 600V rates Ethernet cables must be used to connect racks to racks or racks to controllers.
Visual inspection of SEM3T components, in particular sensors and sensor wiring. Look for nicks/cuts in wire or heat shrink tubing that encapsulates the sensor body. Look for deformation of the sensor screw ring terminal or sensor cylindrical ring terminal. Also refer to Question 21 below.
No connection to a sensor is indicated by “SE” (Sensor Error) instead of temperature reading.
SE stands for Sensor Error.
Compare temperature reading to known good data source.
Replacement procedure depends on how and where malfunctioning components are installed. Consult Siemens for guidance.
• Safety/Construction/EMC
- CSA C22.2 No. 61010-1 Safety Requirements for Electrical Equipment for Measurement.
- UL 61010-1 (IEC 61010-1) Safety Requirements for Test & Measurement.
• Electro-Magnetic Compatibility
- Compliant with UL 61010-1, CAN/CSA-C22.2 No. 61010-1, IEC 61010-1
- Compliant with EMC standards IEC 61326-1, IEC 61326-2-3.
- Compliant with FCC CFR47 Part 15 Subpart B:2018 Class B.
• Security Standards
- Compliant with IoT Security standard OWASP IoT Top 10-2018.
Ethernet - Modbus TCP/IP, 10/100 base-T (100 Mbit/sec), Integrated dual RJ45 ports as standard (can support up to 3 masters and 1 integrated web access simultaneously)
Not available in the default SEM3T webpages, but you could use 3rd party software to read electrical metering current reading and compare with SEM3T thermal data.
SEM3T is powered from a 24V DC power supply and the fusing requirements on the primary size vary based on the power supply.
No calibration is required.
No, SEM3T is limited to temperature monitoring and doesn't monitor voltage or current. For energy monitoring applications, the Siemens SEM3 system should be utilized.
Yes. Follow the installation guide and User Manual, Align the SEM3T sensors, and maintain proper over-surface and through-air clearance requirements as directed by the applicable standards. A dielectric voltage withstand test is recommended after installation to validate wire insulation integrity, as required by the appropriate industry standards.
You don't need software to configure the SEM3T controller. You can configure the SEM3T system by using embedded web pages.
Yes, SEM3T Controllers can be daisy-chained over Ethernet. You cannot have a loop connection.
SEM3T system doesn't lose the data for the data captured prior control power loss. The data is not logged during the power loss period.
16GB of memory with 1 year worth of data.
The temperature measurement is taken at the sensor's point, so it only measures this one spot.
There is no delta point calculation in the current version of the firmware. However, we are planning on implementing this feature in an upcoming firmware version. The customer can upgrade to this firmware when it is released.
The temperature rise is calculated on a rolling window from the data collected by the controller. The user can hover over the data points to see the actual data and time. Each predicted trending data is calculated using the Temperature rise value. Formula is available in SEM3T User manual.
• Recommended locations are mentioned in our literature. Customer preference.
- i. Typically Screw ring terminals are installed on Lug Pads (incoming and Load), Mounted over the lug, Power Connector where horizontal bus connects to vertical bus (Bolted Connections).
- ii. Cylindrical ring terminal is installed on cable insulation for outgoing MCCB breakers. The sensor is installed with a cable zip tie. Or you can hang somewhere in the gear to measure ambient temperature.
- iii. One sensor per phase.
One of the sensors can be attached to an object with a known reference value, e.g., an item at room temperature.
Yes, the micro-SD card comes installed in the product. It is possible to upgrade it by following the instructions in the user guide.