Chinese
Spanish
Russian
Portuguese
French
German
Indonesian
Thai
Vietnamese
Arabic
Italian
Turkish
Polish
Japanese
Level switch installation is complete only when the actual material changes the sensing state and the intended alarm or equipment response follows. Watching a local LED, forcing a PLC input or measuring relay continuity each checks only part of that chain. Use the installation drawing and a written cause-and-effect sequence to connect the physical sensing point to the required action.
Choose the action before drilling the opening
State whether the switch warns an operator, stops filling, inhibits a pump, requests replenishment or detects accumulation. Identify how much material can still enter after the command changes. The physical mounting point has to leave enough time and space for that response; it should not be chosen solely because the opening is easy to reach.
For an overfill duty, assess the highest credible incoming rate, instrument delay, controller delay, valve or feeder stopping time, and material already in transit. Convert the remaining quantity into space using the vessel geometry and the relevant material properties. A cone or irregular vessel cannot be assessed by treating every increment of height as the same volume.
For a low-level duty, decide what must remain covered or supplied during the response. The outlet may lose flow before the whole vessel is empty. Place the sensing point so its uncovered state has a defined operational meaning, and distinguish that state from an electrical failure in the receiving logic where the system design permits.
Level switch installation: position the active sensing region
The METRAVON MV-SP601 uses RF admittance for point detection, with rod and cable arrangements in the model family. Select the active sensing region and insertion length from the proposed assembly drawing. The nominal probe length alone does not tell you the exact level at which every installation will change state.
Avoid an inlet stream that can strike the probe or cover it briefly while the vessel remains mostly empty. Check agitator travel, wall buildup, ladders and nearby conductive parts. For a cable, consider movement during filling and discharge rather than drawing only its stationary position. Do not improvise a bottom anchor to stop movement without approval for that assembly.
For a lined or non-metallic vessel, confirm the required reference arrangement with the model documentation. Mounting a probe through a plastic wall may change the electrical conditions compared with the metal vessel used for a previous installation. Protect the specified reference and shielding arrangement during wiring; do not replace it with a generic grounding assumption.
Separate the material state from the electrical state
Write down the expected local indication, output state, PLC input and equipment action for material present, material absent and power lost. Check terminal numbers against the delivered unit, including the output type and contact rating. A model family name does not define whether a particular output is a dry contact or another electrical arrangement.
| Test | What it checks | What it cannot establish alone |
|---|---|---|
| Real material | Detection with representative material covering and clearing the active region. | Every possible future deposit or operating condition. |
| Output test | Terminals, wiring and response of the receiving input. | Whether the probe can detect the actual material. |
| PLC force | Program logic downstream of the forced signal. | The instrument, field wiring or genuine process response. |
| Power loss | The system's observed response when the instrument loses supply. | All cable faults or every internal failure mode. |
| Full action | Alarm, stopping sequence, final equipment and restart conditions. | Formal safety approval without the required design and assessment. |
Do not connect a motor directly on the assumption that a relay can switch it. Establish the electrical load and control design, including any required intermediate device. Before conducting an operational test, agree isolation, authority to stop equipment and how temporary test settings or bypasses will be removed.
Use covered, clear and coated conditions during commissioning
First establish reliable detection with representative material at the sensing region. Then remove the material and confirm that the switch returns to the intended clear state. Repeat with the normal residue left by the process. Record the material condition and setting rather than keeping only a final pass mark.
MV-SP601's coating-rejection circuitry addresses false responses from adhering material; it does not physically remove a crust or bridge. If the sensor remains covered by a persistent deposit after discharge, inspect the location and deposit mechanism before increasing sensitivity. A setting that detects a weak material change may also become more responsive to residue.
Set delays from the real transient condition and available response time. Passing solids or a brief splash may justify filtering, but the delay must leave enough margin for the required action. Verify both the transition into alarm and the return to normal, especially if clearing allows equipment to restart.
Record the full response and restore the installation
For an authorised test, observe the sensing state, output, controller indication, alarm and final equipment in sequence. Note the delay to the final action. Where process activation cannot be performed safely, use an approved substitute and document exactly which parts of the chain were not demonstrated.
After testing, remove forces and bypasses, restore the approved parameters and confirm the operating mode. Check that an alarm reset does not create an unintended automatic restart. Retain the instrument tag, probe drawing, wiring revision, settings, observed states and any unresolved exception with the equipment records.
Repeat the relevant checks after a material change, probe replacement, relocation or control-logic modification. If the alarm protects a hazardous consequence, the responsible project team must define the necessary independence, approval and test regime. A successful process test is not by itself a safety-integrity certification.
Installation and fault-finding questions
Q1. Does changing high/low mode create another sensing height?
No. Mode changes the interpretation or output behaviour defined by the device, not the physical location of the active probe. Two separate alarm elevations require a documented arrangement that actually senses both points.
Q2. Why does the local indicator change but the PLC does not?
Compare the actual output type, supply, terminal wiring and input configuration. The local sensing indication and output contact are separate observations. Test the field signal at the receiving end before changing the detection sensitivity.
Q3. Can sensitivity be adjusted using a hand near the probe?
Such a response does not establish detection of the process material. Use the prescribed procedure and representative material conditions. Any workshop demonstration should be recorded as a limited electrical or sensing check, not substituted for site acceptance.
Q4. What if buildup causes alarms after the vessel empties?
Record the as-found deposit and switching state before authorised cleaning. Compare covered, residue-only and clear behaviour. Review mounting position and material retention if no usable setting distinguishes those states consistently.
Q5. What information prevents an unsuitable probe quotation?
Provide a section drawing with the required sensing elevation, inlet direction and moving internals. Add material and residue properties, process conditions, vessel construction and the required electrical response. Include removal space and the intended functional-test method.
Summary
The mounting point, probe construction and control response must be reviewed together. Send METRAVON the proposed alarm duty and vessel sketch before ordering. Accept the installation against observed material detection and the required equipment action, with incomplete tests clearly recorded.
