A 175 VAC (volts alternating current) across neutral and ground indicates a major electrical fault. Under typical conditions, there should be a small to no voltage differential between neutral and ground.
Causes
There are some possible reasons for this high voltage reading:
Open Neutral
An open (or) broken neutral wire can disrupt the voltage distribution. This can result in unexpectedly high voltage between neutral & ground.
Poor Grounding
Insufficient or defective grounding can cause a considerable voltage differential between neutral and earth.
Proper grounding ensures safety by creating a path for fault currents.
Faulty Equipment
A malfunctioning electrical device or equipment could be creating the high voltage.
Faulty appliances can cause an aberrant voltage potential between the neutral and ground.
Incorrect Wiring
Wiring faults, such as inverted neutral and hot wires, might result in unexpected voltage levels. Ensure that all connections are properly and securely formed.
Induced Voltage
In rare conditions, electromagnetic interference (or) inductive coupling from neighboring high voltage lines or equipment may result in a voltage between neutral and ground.
Solution
Immediate Safety Check
Turn off the concerned circuit and consult with a licensed electrician.
Inspect Connections
Look for loose, corroded, (or) damaged connections at the breaker panel & outlets.
Verify Grounding
Make that the grounding system is correctly developed and fulfills local electrical requirements.
Test Equipment
Disconnect & test electrical devices to find any problems.
Safety comes first, thus professional testing and maintenance are required to avoid electrical dangers.