how does an ac surge protector work on an rv?

[John Frum]

In a typical RV the only connection to a grounding electrode occurs when the shore power cord is attached to the pedestal.

An induced surge could come into the system on the shore power cord.
During the surge; hot, neutral and ground could all be at several thousand volts.
When the surge protector activates, its going to try to shunt hot and neutral to ground via the grounding electrode upstream of the pedestal.
Am I understanding this correctly?

 

[John Frum]

Assuming you are connected to shore power...
If you have surge protection device on the pv domain it is also going to shunt to ground via the grounding electrode upstream of the pedestal?

What happens if there is no path to the dirt because you are not connected to shore power?

 

[Checkthisout]

In a typical RV the only connection to a grounding electrode occurs when the shore power cord is attached to the pedestal.

An induced surge could come into the system on the shore power cord.
During the surge; hot, neutral and ground could all be at several thousand volts.
When the surge protector activates, its going to try to shunt hot and neutral to ground via the grounding electrode upstream of the pedestal.
Am I understanding this correctly?

It connects hot and neutral. Neutral to ground. Depending.

Surge protectors are not lightning arrestors so no grounding rod is needed for them to operate.

In your example, you say during your theoretical surge that all 3 conductors are at the same voltage potential that would be a lightning strike.

 

[John Frum]

It connects hot and neutral. Neutral to ground. Depending.

Surge protectors are not lightning arrestors so no grounding rod is needed for them to operate.

In your example, you say during your theoretical surge that all 3 conductors are at the same voltage potential that would be a lightning strike.

An induced surge is not necessarily a lightning strike.

 

[Supervstech]

An induced surge is not necessarily a lightning strike.

True, but induced surges aren’t above 400V usually either, and you said thousands…
Lightning of course could be millions…

 

[time2roll]

There is some surge protection using MOV thyristors or similar. Also monitors voltage and if out of range opens the relay. Also tracks N-G bond and will open the relay. Frequency is monitored with again the relay as the disconnect.

Close hit from lightning... forgetaboutit. Going to jump right over.

https://www.progressiveindustries.net

 

[Zwy]

Assuming you are connected to shore power...
If you have surge protection device on the pv domain it is also going to shunt to ground via the grounding electrode upstream of the pedestal?

Probably not, how would the surge from the pedestal enter the PV? In order to have an inverter onboard an RV and still maintain shore power capability, a transfer switch is a requirement.

What happens if there is no path to the dirt because you are not connected to shore power?

If you are inline with a lightning strike in your RV and it jumps to dirt, you're screwed. But you said no path to dirt.

 

[Checkthisout]

An induced surge is not necessarily a lightning strike.

A good example is a tree striking the 115kv high line and then connecting with a service drop or secondary line lower on the pole.

This happens at my house only the lower line is phone and TV.

These surges do not reach the equipment because the coax is grounded to power at the service entrance, not because it's connected earth.

 

[Checkthisout]

An induced surge is not necessarily a lightning strike.

So if all 3 conductors are at same potential, why would the equipment get damaged?

 

[John Frum]

So if all 3 conductors are at same potential, why would the equipment get damaged?

Good point.
If there is no path to ground and everthing is at the same potential I don't see a problem.

 

[John Frum]

@time2roll gave me the info I was looking for.
In addition to varistors the rv shore power surge protector has relays to isolate the rv.

 

[John Frum]

Probably not, how would the surge from the pedestal enter the PV?

On the wires between the pv panels and the solar charge controller.

 

[Supervstech]

A good example is a tree striking the 115kv high line and then connecting with a service drop or secondary line lower on the pole.

This happens at my house only the lower line is phone and TV.

These surges do not reach the equipment because the coax is grounded to power at the service entrance, not because it's connected earth.View attachment 131070

Lightning strikes do need a path to earth…

 

[Checkthisout]

Lightning strikes do need a path to earth…

Yes. For an RV, that path is the ground rod at the pedestal.

 

[Pappion]

Some campgrounds require your RV to have a surge protector. Maybe they don't trust the power company.
Every campground I have been to uses buried power lines to the pedestal. That reduces local lightning strikes.

 

[Pappion]

So if all 3 conductors are at same potential, why would the equipment get damaged?

Your assuming they all hit that potential at the same instant, not likely.
I also did ESD testing on various chip designs. Some of the energy will slip thru, which is why a 2 stage approach is used.
That pulse is actually a complex mixing of frequencies (wave lengths) some of them will be at zero volts right where you short them all to ground. That energy passes right thru. This was easy to explain to RF designers.

 

[Checkthisout]

Your assuming they all hit that potential at the same instant, not likely.
I also did ESD testing on various chip designs. Some of the energy will slip thru, which is why a 2 stage approach is used.
That pulse is actually a complex mixing of frequencies (wave lengths) some of them will be at zero volts right where you short them all to ground. That energy passes right thru.This was easy to explain to RF designers.

Point being, their are different kinds of surge protectors.

Surge protectors can protect from lightning but it depends on the setup.

 

[Pappion]

I use clip-on ferrite beads through out my RV 12v wiring and PV wiring at SCC. Very cheap. Maybe I should add some to AC too.
ferrite beads