SDJ-301 Shaft Vibration Protection Transmitter with 4-20mA Output and Two-Stage

Product Specification

Fault Monitoring:
  The SDJ-301 shaft vibration protection transmitter monitors the radial vibration of rotating machinery rotors, and can measure shaft vibration, runout, eccentricity, etc.It monitors increased vibration caused by rotor imbalance, misalignment, loose components, etc.

Measurement parameter:
  Peak-to-peak value of radial vibration (displacement).

Unit type:
  Rotating machinery with various sliding bearings, such as steam turbines, fans, compressors, motors, pumps, etc.

Output Interfaces:
  ● Active output terminals with 4-20mA or 1-5V.
  ● Local LED display showing machine operating status (instrument working status OK, alarm Alert, interlock Danger, break).
  ● Isolated two-stage alarm relay output terminals ("ALERT" and "DANGER" normally closed or normally open output terminals).
  ● Local alarm reset button with automatic reset function.
  ● For local display, it can be connected to a QBJ-3Q digital display and displayed as vibration value via PLC or DCS.
  ● Buffered output of the raw signal, directly connected to a status diagnostic analyzer ("BUF OUT" output terminal).
  ● 24VDC, 220VAC, or 110VAC power supply, with the 220VAC or 110VAC option equipped with an isolated power supply.

Continuous vibration monitoring system:

   The SDJ-301 is a single-channel vibration protection transmitter.
   It is primarily used for online real-time measurement of the radial vibration of the rotor shaft in rotating machinery. It outputs the peak-to-peak displacement of the vibration and simultaneously outputs two-level alarms. This allows for early detection and alarm protection of rotating machinery, extending its service life and reducing maintenance.
   The low-frequency option of the SDJ-301 can measure low-frequency parameters such as turbine runout, steam turbine shaft vibration, and eccentricity. Installation is simple and convenient, requiring no adjustments, and it offers a high performance-to-price ratio.

   The SDJ-301 shaft vibration protection transmitter is suitable for vibration monitoring of machines with sliding bearings. The SDJ-301 is easy to install, directly in the original location of the preamplifier. For the measured point on the machine, we generally require two SDJ-301 transmitters, one X and one Y, spaced 90° apart, to be installed near the bearing. For standard dual-bearing rotating machinery, four vibration transmitters are typically configured.

   The SDJ-301 protection transmitter has all parameters pre-adjusted and calibrated before leaving the factory. Simply connect the corresponding cables; generally, no further adjustments or calibrations are required. However, the SDJ-301 also offers complete adjustment functions, including adjustable parameters such as two-level alarm points, zero point of vibration output, and full-scale calibration. By opening the SDJ-301 protection transmitter's nameplate, you can adjust the two-level alarm point settings and the zero point "ZERO" for the 4-20mA output. You can also calibrate the instrument's full-scale range by removing it from the housing. With its multi-channel protection capabilities and flexible options, the SDJ-301 protection transmitter can be tailored to your specific needs.

    The SDJ-301 protection transmitter can be customized to meet various field requirements, with its functions selected according to the ordering options. The SDJ-301 protection transmitter can output a total vibration value of 4–20 mA, features two-level alarms, buffered output of the original signal, and field alarm reset. Different full-scale ranges are available for selecting the total vibration value, and a low-frequency option is also specifically provided for measuring turbine runout and steam turbine eccentricity.

    The 4-20mA output is active and can drive loads up to 750Ω, i.e., more than three loads. Connection requires each load to be connected in series with the output terminal. The SDJ-301 is a 3-wire protection transmitter. For this transmitter, note that the system requires single-point grounding; that is, the negative terminal of the 4-20mA output and the negative terminal of the power supply must be the same "system ground" (COM). The two-stage relay output is a fully isolated dry contact output. The relay is an SPDT single-pole double-throw type, which can be connected to normally closed or normally open terminals. The maximum relay load is 2A. It can be directly connected to any PLC or DCS, and can also control alarms, relays in units, etc.

    The SDJ-301 can be used with 8mm eddy current sensors. The standard sensor includes a probe and extension cable; users can also choose an armored cable system.