Hello! Our Groundung device gives alarm at over 50mV. But i changed all silver graphite brushes, remove slip rings and clean shaft surface then reinstalled (resistance of slip rings and shaft after installation is zero ohms which is good) spring tension adjusted to the max. Canni checked the mV using voltmeter? I have checked all cable terminals/lugs connection. All is ok. All grounding xable also checked. But still gives 50mV...
To prevent spark erosion which can developed in between the shaft and the main bearings .. The potential difference that is voltage developed only when the shaft is rotating and there is breakage of lubricating oil film between the shaft and bearings. Due to voltage or potential developed there will be spark produced due to dissimilar metals are in contact.. These sparks can damage both the bearings and shaft especially bearings.. The damages caused by the spark is nothing but spark erosion. And that's why we are grounding this current.. indirectly the potential.
Because the shaft is seperate to हल body by Lubricating oil film. And also since it's rotating which creates a micro magnetic field..and thus a potential difference.
Thank you sir,very clearly explained to understand even for juniors !.
Hello! Our Groundung device gives alarm at over 50mV. But i changed all silver graphite brushes, remove slip rings and clean shaft surface then reinstalled (resistance of slip rings and shaft after installation is zero ohms which is good) spring tension adjusted to the max. Canni checked the mV using voltmeter? I have checked all cable terminals/lugs connection. All is ok. All grounding xable also checked. But still gives 50mV...
YES YOU CAN CHECK THE mV USING VOLTMETER
why not a similar system fitted for alternator ?
sir, properller shaft is non metallic, can you pls tell us which material is used?
Nab... nickel aluminum bronze
What is the main puroposr or use of haft grounding?
To prevent spark erosion which can developed in between the shaft and the main bearings ..
The potential difference that is voltage developed only when the shaft is rotating and there is breakage of lubricating oil film between the shaft and bearings.
Due to voltage or potential developed there will be spark produced due to dissimilar metals are in contact..
These sparks can damage both the bearings and shaft especially bearings..
The damages caused by the spark is nothing but spark erosion.
And that's why we are grounding this current.. indirectly the potential.
@@siddhushah007 main bearing or stern tube bearing?
How the potential diff occurs between the shaft and the hull
Because the shaft is seperate to हल body by Lubricating oil film. And also since it's rotating which creates a micro magnetic field..and thus a potential difference.
picture very small very difficult to see..