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Terasaki ANU-1 OCR Checker The ANU-1 is a dedicated test instrument from Terasaki for verifying the functionality of Over-Current Relays (#OCRs) in circuit breakers. • Typical model reference: “AC110-240 V ANU-1 OCR Checker”. • It is described as “compact and portable” for field-testing OCRs (over-current releases) in industrial/utility installations. What functions does it check? ANU-1 is capable of checking the following: • Long time-delay trip (pickup and time) • Short time-delay trip (pickup and time) • Instantaneous trip (pickup current) • Ground-fault trip (pickup and time) • Pre-trip alarm function (for breakers with a pre-alarm before full trip) So if you are dealing with breakers (or ACB/OCR combinations) that have multiple stage over-current protection, this instrument is very useful. Key Specifications & Features • Supply voltage: AC 110-240 V (50/60 Hz) version. • Power consumption: Approximately 7 VA. • Single connector interface for the OCR under test (simplifies field connection). • Clear LCD display showing the function, phase output and trip signal indicators. • Light weight (in one rental listing: ~1 kg) and portable carrying case. Typical Use Cases — Relevant to your site work Given your context (ships, switchgear, protection systems), here’s how this tool comes in handy: • If you need to verify the OCR section of a breaker (especially the over-current release unit) after settings changes or installation, the ANU-1 lets you simulate fault currents and trip times. • On board a vessel, especially when you have ACBs (#aircircuitbreakers) with OCRs, this tool helps confirm that the over-current protection is still within spec (pickup/trip time) and that the pre-trip alarm (if present) is functioning. • For maintenance or commissioning of switchgear, you can use the ANU-1 to validate the OCR without having to fully load the circuit or create actual fault conditions — saving risk and downtime. Important Usage & Safety Notes A few key cautions pulled from the manual and associated documentation: • Before testing, isolate the #breaker under test (ensure upstream circuit breaker is open, remove control power, etc.). • After testing or changing OCR settings, return settings to original values. Failure to do so may cause fire or burnout. • The instrument itself is electronic; avoiding shock, dropping or mechanical damage is important. • Make sure during connection that the current being applied does not exceed permissible values for the OCR or wiring (excess current may damage the breaker or the tester). • Ensure the device is connected properly, power off while connecting/disconnecting to avoid inadvertent trip. How this relates to your environment (ships, switchgear, etc) Given your work with marine electrical systems, parallel generators, #protection etc, here’s how this tool could support you: • On board ship #switchgear with #ACBs that include OCRs, you can carry the ANU-1 to check OCR functionality in situ after maintenance or fault events. • When you suspect an over-current protection issue (e.g., nuisance trips, no trip when expected) in a breaker’s OCR unit, you can use the #ANU-1 to measure pickup/trip values and compare to the breaker/OCR spec. • If the breaker’s #OCR has undergone setting changes (for example to adapt to changed loading conditions), you can validate those changes using the ANU-1 to ensure compliance with protective requirements. • In a #vessel environment, where downtime is critical and fault simulation is high risk, using a dedicated OCR tester like this reduces the need for full fault injection or burning equipment.

The green discs are #varistors (MOV – Metal Oxide Varistors). They are mounted across the #transformer terminals as overvoltage protection devices. Their purpose: • absorb #voltage spikes and surges (lightning, switching spikes, generator noise); • #protect the transformer windings and downstream electronics; • clamp the voltage to a safe level by diverting excess energy to ground. ✅ Why there are three of them, and why they are connected to ground You normally place one #MOV on each phase, connected: Phase → MOV → Ground This way, any surge on any #phase is discharged safely to ground. This is a standard arrangement in: • marine control equipment, • power supplies, • #UPS input filters, • automation transformers. ✅ How to know if a varistor is faulty ✅ 1. Visual inspection A bad MOV usually shows: • cracks in the disk, • dark burn marks, • pieces of coating missing, • a burnt smell, • swelling. ✅ 2. #Multimeter test A good MOV shows very high #resistance at low voltage. If your meter shows: • Low resistance (a few ohms) → the MOV is shorted (failed) • Normal infinite resistance → likely OK (or open-circuit, which also means no protection) You cannot fully test the MOV without high-voltage equipment, but a shorted MOV is easy to detect. ✅ 3. Symptoms in the system If a MOV is shorted: • #breakers/ fuses blow, • transformer hums heavily, • input voltage drops, • the device won’t power up. If a MOV is open-circuit: • the system works normally • but you have no surge #protection anymore. ✅ How to check if the #transformer itself is healthy • Measure winding resistance (similar between phases if 3-phase). • Check no-load current (should be small). • Measure output voltage under load. • Ensure no #overheating.

A Multipurpose Controller (#MPC) in a #MAN B&W main engine is a modular electronic controller used in the ME-engine control and safety system. It is part of the ECS (Engine Control System) and handles specific control tasks, depending on how it is configured. ✅ Main purpose of the MPC The MPC is essentially a #PLC-type module placed inside the #Engine Control Room (ECR) cabinet or local control cabinets. Each MPC is assigned one or more functions, such as: ✅ Typical functions of MPC modules on MAN ME engines Depending on the engine type (ME, ME-C, ME-B), MPCs may handle: 1. Fuel Injection Control • Controls the Hydraulic Cylinder Units (#HCUs) • Controls timing and quantity of injection • Receives feedback from #MOP sensors, #FIVA valves, pressure sensors 2. Exhaust Valve Control • Commands opening/closing via hydraulic oil distributor • Monitors valve position feedback 3. #Cylinder Lubrication Control • Controls Alpha Lubricators • Adjusts cylinder oil feed rate based on load, #SFOC, sulfur level 4. Safety Monitoring • Monitors critical sensors: • Scavenge air pressure • Exhaust temp • Fuel rail pressure • Hydraulic oil pressure • Turning gear position • Can initiate slowdown, shutdown, or load reduction 5. Starting Air System Control • Controls air start valves • Monitors starting air distributor signals 6. Auxiliary Systems • Maneuvering commands • Governor interface • Shaft generator logic (on some setups) ✅ Communication The MPC communicates with: • #DCU (Diesel Control Unit) on each cylinder • #ECS Main Controller (#SIGMA, #CoCoS, or later versions EICU) • Scavenge air temp controller • Bridge and ECR interfaces • Communication is typically via redundant #CANbus or MAN proprietary bus. ✅ Hardware features • Modular I/O board (analog & digital) • #CPU board • Power supply section • Rugged design for vibration & heat • Hot-swappable in some engine versions ✅ Typical number of MPCs A typical #ME engine has several MPCs, e.g.: • MPC-A – Fuel system • MPC-B – Exhaust valves • MPC-C – Safety & protection • MPC-L – Cylinder lubrication (Names differ by project and wheelhouse specification.) ✅ If you are troubleshooting Common MPC issues include: • “MPC Communication Lost” • “MPC I/O Board Error” • Faulty 24V supply • CAN bus errors • Loose connector pins • Firmware mismatch after replacement

Replacing a synchronous motor on an anemometer ℹ️ Related article ➡️ The anemometer gives false readings. Troubleshooting https://www.eto-engineer.com/2023/09/the-anemometer-gives-false-readings.html #anemometer

Can 24.34VDC batteries be used to calibrate a 24VDC pressure transmitter? #Span #Zero #calibration #pressuretransmitter #pressure #transmitter

The replacement interval for bearings in marine electric #motors depends on operating conditions, motor design, and maintenance quality. On average, bearings in marine motors last between 20,000 and 40,000 hours under normal temperature and acceptable vibration levels. For motors exposed to heavy loads or #vibration (such as winches), the service life may be reduced to 10,000–20,000 hours. Open Bearings require regular lubrication, usually every 2,000–4,000 operating hours. Marine-grade anti-emulsion greases, such as Mobil Polyrex EM or SKF LGHP 2, should be used since they resist moisture and salt. #Bearing condition should be monitored through vibration Analysis and temperature measurement. These checks are recommended at least once a month. If vibration exceeds 4.5 mm/s RMS or temperature rises above 95°C, the bearing should be replaced. Even if the motor operates normally, bearings are typically replaced every 4–5 years, or after about 30,000 hours of service. For critical equipment, such as main pumps or engine room ventilation #motors, bearings are often renewed during each major #overhaul. If a #motor has been idle for a long time, bearings may suffer from corrosion or “sticking.” Before starting, the shaft should be rotated manually to ensure it turns freely. #Bearings wear out faster under certain conditions, such as moisture ingress, overheating, shaft misalignment, rotor imbalance, excessive belt tension, or use of incorrect grease.

A #temperatureswitch is a device that monitors temperature and activates (or deactivates) an electrical circuit when a certain preset temperature is reached. 🔧 How it works: • Inside the #switch, there’s a temperature-sensing element (like a bimetallic strip, thermistor, or gas-filled bulb). • When the temperature rises or falls to the setpoint, the #sensor changes shape or #resistance. • This action opens or closes electrical contacts — turning equipment on or off automatically. ⚙️ Typical functions: • Turn cooling #fans on when a system gets too hot. • Turn #heaters off when a set temperature is reached. • Trigger #alarms when overheating occurs. 🧩 Types: 1. Mechanical temperature switch – uses a bimetal or expansion element (no power needed). 2. Electronic temperature switch – uses a thermistor or RTD and electronic circuit for precise control. 🛠️ Applications: • #Engine and #motor protection • #HVAC systems • Industrial process control • #Overheat #protection in generators or pumps

A #floatlevelswitch is a type of sensor used to detect the level of liquid in a tank or vessel. It works by using a floating element (the float) that rises and falls with the liquid level. When the float reaches a certain point, it activates or deactivates an electrical switch, sending a signal to a control system or alarm. Here’s a breakdown of its main parts and working principle: ⚙️ Main Components 1. Float – A buoyant object that moves with the liquid surface. 2. Stem or Arm – Connects the float to the switch mechanism. 3. #Switch mechanism – Usually a magnetic reed switch or micro switch that opens or closes the circuit based on float position. 4. Housing – Protects the internal parts; may be stainless steel, plastic, or brass depending on the application. 🔍 Working Principle • When the #liquid #level rises, the float moves upward. • This movement changes the state of the internal switch (e.g., from open to closed). • The signal can be used to: • Start or stop pumps • Trigger alarms • Control valves • Protect equipment from dry running or overflow ⚡ Types of Float Level #Switches 1. Vertical type – Mounted from the top or bottom of a tank; float moves up/down along the stem. 2. Horizontal type – Mounted from the side; float swings inward/outward as the level changes. 3. Cable type – Float is attached to a flexible cable; used in large tanks or sumps. 4. Multi-point type – Detects multiple liquid levels with several switches on one stem. 🧰 Applications • Ballast #tanks • Freshwater and fuel oil tanks • Bilge systems • Cooling systems • Sewage treatment plants • Hydraulic oil reservoirs ⚠️ Common Problems • #Float stuck due to debris or corrosion • Magnetic failure (in reed switch type) • Incorrect installation angle • Electrical connection failure

Working at #Heights: Safe Use of Fall Restrainers and Fall Arresters Working at heights poses serious risks and requires strict adherence to safety procedures. According to the UK Department of Transport (UK DoT) definition, any work conducted above 2 meters with a potential risk of falling qualifies as “working at heights.” For such tasks, a permit to work and appropriate fall protection equipment are mandatory. There are two main types of fall protection systems, each serving a distinct purpose: 1. #FallRestrainer – A safety system (such as a safety belt or harness with a lanyard) designed to prevent a worker from reaching a position where a fall could occur. 2. #FallArrester – A system with a body harness designed to stop a fall that has already started safely. The Safety Officer determines whether a restrainer or arrester is required, depending on the nature of the job and the associated risks. For instance, work in elevated areas without guardrails or operations overboard (e.g., rigging the accommodation ladder) require the use of a fall arrester with a full body harness. Donning and Inspection Before using any fall protection system, the equipment must be carefully inspected. The user must ensure that: • Belts, straps, metal components (D-rings, hooks, etc.), and lanyards are free from damage or corrosion. • The retractable lifeline operates smoothly and locks properly when tested. • The safety harness is worn tightly, checked by another crewmember, and the hook of the arrester is properly engaged. The stronghold (anchorage point) on the ship must be inspected to ensure it is structurally sound, has no sharp edges that could damage the lanyard, and can withstand a load of at least 500 kg. Only a full-body #safety #harness (not a safety belt) can be used with a fall arrester. #Fall Clearance Distance When setting up a fall arrester system, the fall clearance distance must be calculated correctly. This distance should exceed the total distance a worker might fall before being stopped by the system. It includes: 1. Length of the lanyard 2. Length of the deployed energy #absorber (once activated) 3. Worker’s height 4. Safety factor (for vessel motion or protruding fittings) An overhead anchoring point is preferable since it provides less fall distance compared to anchoring from the floor. Maintenance When not in use, fall arresters, safety harnesses, and belts must be stored in a dry room, away from sunlight and chemicals. They must not be hung by their metal parts. Monthly inspections should follow the manufacturer’s manual, checking for: • Rust or structural failure, • Paint, grease, or salt buildup (cleaning required), and • Completeness of all components. Some manufacturers may require annual servicing, which must be arranged accordingly. All inspections and maintenance activities are recorded in the Planned Maintenance System (#PMS). A fall arrester must be replaced every five years. Rescue Procedures In the event of a fall, immediate recovery of the crewmember is essential. The person must not be left hanging, as suspension trauma can occur — a condition where blood pools in the legs, reducing circulation to the brain and vital organs. After #rescue: • The worker should be placed in a sitting position (never laid flat) for at least 30 minutes to stabilize blood flow. • Medical supervision should follow. • The #fallarrester and harness used during the incident must be discarded, as internal damage may not be visible. Proper inspection, maintenance, and understanding of fall #protection systems are essential for preventing serious injuries or fatalities during work at heights. Every crewmember must ensure that their fall restrainer or arrester is in good working condition and used according to procedures. Safety begins with preparation — a moment of care can prevent a lifetime of regret.

🧠 What Is the Kalman Filter? The #Kalman #Filter is a mathematical algorithm used to estimate the true state of a dynamic system that is affected by noise and uncertainty. In simple terms, it’s a smart way to combine predictions from a model with noisy sensor measurements to obtain the most accurate possible estimate of what’s really happening. 🔍 Basic Idea At every time step, the filter performs two main actions: 1. Prediction: It predicts the next state of the system based on the previous state and a mathematical model. 2. Correction (Update): It compares this prediction with a new measurement from a sensor and adjusts the prediction depending on how much it trusts the sensor vs. the model. This process repeats continuously, giving a constantly updated “best guess” of the system’s true state — even when measurements are noisy or incomplete. ⚙️ Why It’s Called “Kalman Filter” The name comes from Rudolf Emil Kalman, an American engineer and mathematician of Hungarian origin, who introduced the filter in his 1960 paper: “A New Approach to Linear Filtering and Prediction Problems.” It’s called a filter because it literally filters out noise from data — extracting the most probable signal from uncertain or fluctuating measurements. Kalman’s method became world-famous after being used in the Apollo space program to help guide spacecraft to the Moon. 📊 Where It’s Used The #KalmanFilter is widely applied in: • #Navigation systems (#GPS, inertial sensors, #autopilots); • Aerospace and marine control systems; • #Robotics and object tracking; • Signal processing and sensor fusion; • Economics and data prediction. Anywhere you have uncertain measurements and need reliable estimates — you’ll often find a Kalman Filter. ⚖️ The Kalman Gain — the Heart of the Filter The #KalmanGain, usually denoted as K, determines how much the filter should trust the new measurement compared to the predicted value from the model. It’s a weighting factor — balancing the reliability of the model and the #sensor. 🔧 Intuitive Explanation • If the sensor is accurate (low #noise), the Kalman Gain K becomes large, and the filter trusts the measurement more. • If the sensor is noisy, K becomes small, and the filter trusts the prediction more. 🚢 The Extended Kalman Filter estimates the vessel's heading, position and velocity in each of the three degrees of freedom - #surge, #sway and #yaw. Il also incorporates algorithms for estimating the effect of sea current and waves The Extended Kalman Filter uses a mathematical model of the #vessel. The mathematical model itself is never a 100% accurate representation of the real vessel. However, by using the Extended Kalman filtering technique, the model can be continuously corrected. The vessel's heading and position are measured using the gyrocompasses and position-reference systems, and are used as input data to the #SDP system. These measurements are compared with the predicted or estimated data produced by the mathematical model, and the differences are then used to update the mathematical model to the actual situation.

Fear and Loathing in the Engine Room. Feel the atmosphere 🤯 #EngineRoom #ER

🧩 A puzzle of diagrams scattered across various manuals (Main Control Console, Main Engine, Wiring diagrams) and information from the MOP. Not all the diagrams are included (I didn't attach any minor ones related to the 24VDC power supply). ➡️ For reference. I've replaced these #converters on other vessels, so keep this in mind. 💡 Note how the #MOP tells you where the problem lies (in the cable or in the #sensor). Unfortunately, this isn't enough to give a complete picture, as at least three signal #amplifier converters are involved in the circuit. Perhaps in the future, all the components will be shown, but then the ETO won't be needed anymore. 🤷‍♂️ Or is that right? 😅 #troubleshooting #turbocharger #RPM

The essence of troubleshooting is to assemble a puzzle from all the available diagrams scattered across various manuals and find the problem. This is very inconvenient and wastes a lot of time. ⚠️ In the photo, the ME turbocharger RPM signal conditioner failed. The corresponding alarms initially went off on the #AMS and #MOP, but the #tachometer on the main console remained operational, meaning the pickup sensor remained functional. ➡️ In short. The 4-20mA signal from the #pickup sensor goes through two junction boxes and several terminal boards to the Frequency Converter, from there to the tachometer and Signal Conditioner, which in turn goes to the AMS and #SCU (via an Isolation #Amplifier). 🧩 Below is a puzzle of #diagrams 👇 #troubleshooting #turbocharger #RPM

The main element of a #pressure #switch is the sensing element, which reacts to pressure and converts it into mechanical force to open or close the contacts. Depending on the design, it can be: • #Diaphragm – a thin elastic plate that deflects under pressure changes. • #Bellows – a corrugated cylinder that expands and contracts. • #Piston – moves under the force of the process pressure. This element “senses” the pressure and transfers the force to the spring and #contact mechanism, which then generates the electrical #signal (ON/OFF).

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Pressure transmitter calibration (full video) #Span #Zero #calibration #pressuretransmitter #pressure #transmitter

Span calibration on the pressure transmitter #Span #calibration #pressuretransmitter #pressure #transmitter

Zero calibration on the pressure transmitter #Zero #calibration #pressuretransmitter #pressure #transmitter

What #mV values ​​should a #thermocouple have?

The #WTS (Water Treatment System) for EGR (Exhaust #Gas Recirculation) on a vessel is used to clean the wash water that comes into contact with exhaust gases during the EGR process. Key points: 1. Purpose of #EGR • Reduces the formation of nitrogen oxides (#NOx) by recirculating part of the exhaust gases back into the engine’s intake. • Water is used for cooling and cleaning these gases. 2. Why WTS is needed • The water used in EGR absorbs soot, #SOx, heavy metals, and other pollutants from the exhaust. • #IMO Tier III and #MARPOL Annex VI regulations require this water to be treated before discharge overboard. 3. Main functions of WTS • Filtration: removal of solid particles, soot, and ash. • Turbidity control: reduction of water cloudiness. • pH neutralization: dosing of alkaline chemicals (typically #NaOH) to maintain pH > 6.5. • Cooling: ensuring the discharge temperature is within allowed limits. • Monitoring: continuous control of pH, turbidity, #PAH, and temperature. 4. Typical components • Settling tank or particle separator. • Filtration units (cartridge filters, centrifuge, or hydrocyclone). • #pH dosing unit (alkali addition). • Sensors for pH, turbidity, temperature, and sometimes PAH. • Control and logging system (required for MARPOL compliance). 5. Operational features • Requires regular filter cleaning and maintenance. • Monitoring data must be logged and stored (usually at least 18 months). • Automatic overboard discharge lock is required if parameters go out of range. ⚠️ More information is available in our private channel ➡️ Marine Engineering Manuals ⭐️