Meiyo sensors
Temperature and pressure sensors for the alarm system
Finished plan for the engine-room monitoring sensors: Pt100 thermo-resistance bulbs with measuring point list, 4–20 mA pressure transmitters with test pieces and gauge valves, Danfoss KPS thermostats and RT pressure switches. It includes specifications, maintenance and inspection intervals for the bulbs, zero and span adjustment of the transmitters, and setting of the thermostats (range and differential).
Click a part on the model to see its number and purpose.Open the 3D manual
Maintenance procedures
Pressure transmitter zero and span
- Power the transmitter for 20 minutes. p. 35
- Disconnect it from the pipe so it sees no pressure; output should be 4 mA ±1 % F.S.; if not, remove the blind screw and adjust ZERO. p. 35
- Reconnect, apply maximum range pressure, output should be 20 mA; adjust SPAN if needed. p. 35
- Repeat zero and span until both are correct. p. 35
Setting a KPS thermostat
- Loosen the locking screw between the spindles. p. 38
- Set the upper (function) temperature on the range spindle and the differential on the differential spindle, e.g. 95 °C with 5 °C differential for a cooling water alarm. p. 38
- Retighten the locking screw; fit the sensor in its pocket with heat-conductive compound. p. 38
Maintenance intervals
| Item | When | Action | Manual |
|---|---|---|---|
| Resistance bulbs — mechanical | 1 month after install, then 6 months | Inspect | p. 23 |
| Resistance bulbs — electrical and cleaning | 1 month after install, then yearly | Check insulation and clean | p. 23 |
Technical specifications
| Resistance bulb | Pt100, class B (DIN/IEC), tolerance ±(0.3 + 0.005 t) °C, 5 mA | p. 2 |
|---|---|---|
| Insulation | ≥ 10 MΩ at DC 500 V at normal temperature | p. 2 |
| Pressure transmitters | DC 24 V supply, 4–20 mA output, ranges 0–4.0 / 1.6 / 1.0 / 0.6 MPa, −0.1–0.4 MPa | p. 3 |
| Transmitter accuracy check | 4 mA at no pressure, 20 mA at full scale, ±1 % F.S. | p. 35 |
| KPS thermostat contacts | AC 10 A ohmic / 6 A inductive at 440 V, IP67, −40…+70 °C ambient | p. 38 |
Source: manufacturer's manual “EM-38 THERMO RESISTANCE BULB-TRANSMITTER-THERMOSTAT-PRESSURE SWITCH”, 63 pages. Page numbers refer to the original. Check against the manual on board before work.