When troubleshooting a magnetic controller,...

When troubleshooting a magnetic controller,...

Question 1 of 270705eccefa4bacbc34ba4d4850c

When troubleshooting a magnetic controller, it is found that the contacts are welded together. What is the most probable cause?

Question 1 of 27070

Q

When troubleshooting a magnetic controller, it is found that the contacts are welded together. What is the most probable cause?

🔍 Key Concepts

• Magnetic controller operation – how the coil voltage affects the strength of the magnetic pull on the moving armature and contacts • Contact arcing and chatter – what operating condition causes contacts to open/close rapidly or not pull in firmly, leading to heat and welding • Difference between steady, firm contact pressure vs weak, intermittent contact

💭 Think About

• Think about which condition would cause the contacts to not be pulled tightly together, allowing arcing every time current flows. • Which option would make the magnetic field in the operating coil too weak, causing the armature and contacts to chatter instead of closing solidly? • Consider which choice would increase arcing and heating at the contacts over time, rather than just raising the general temperature of the device.

✅ Before You Answer

• Verify which option would lead to a weak magnetic field in the coil, rather than a stronger one. • Check which condition is most likely to cause contact chatter and heavy arcing, which in turn can weld contacts together. • Eliminate any choices that only affect overall temperature or mechanical wear but do not cause repeated arcing at the contact surfaces.