Caravan hook ups

[Doomed]

Testing a touring site for the first time - a.n.other has been doing it for years.
Incoming TNCS to glorified shed in field, outputs to hook ups earthed by SWA sheath, not connected to the big metal dis board, terminated in plastic boxes and connected to a rod so is theoretically TT'ed.
However, the readings I was getting at the hook ups seemed too good to be true, so after disconnecting everything from the rod I measured the resistance between the rod and the earth in the dis board (the TNCS earth). Result was 25 ohms.
As I said, the rod was disconnected from ever thing, so logically the resistance was through the ground.

Is this OK?

Also, elsewhere there is a poor connection in the armour between 2 hook ups, not too bad but notable. Is it worth putting another rod at this point.

 

[davesparks]

What Ra did you get for the rods and what test method did you use?

 

[richy3333]

Testing a touring site for the first time - a.n.other has been doing it for years.
Incoming TNCS to glorified shed in field, outputs to hook ups earthed by SWA sheath, not connected to the big metal dis board, terminated in plastic boxes and connected to a rod so is theoretically TT'ed.
However, the readings I was getting at the hook ups seemed too good to be true, so after disconnecting everything from the rod I measured the resistance between the rod and the earth in the dis board (the TNCS earth). Result was 25 ohms.
As I said, the rod was disconnected from ever thing, so logically the resistance was through the ground.

Is this OK?

Also, elsewhere there is a poor connection in the armour between 2 hook ups, not too bad but notable. Is it worth putting another rod at this point.

I don't understnad what you're saying. Are you saying the TNCS Earth was 25 ohms?

why put a rod in for a poor connection between 2 hook up points? Don't the connections need improving/fixing?

 

[davesparks]

I don't understnad what you're saying. Are you saying the TNCS Earth was 25 ohms?

why put a rod in for a poor connection between 2 hook up points? Don't the connections need improving/fixing?

The rods are there because they are caravan hookups.

 

[richy3333]

I understand that it's a TT earthing system, but I dont understand the scenario described? If the earth between 2 hookups(for example the SWA isn't terminated correctly causing a 'poor connection') why stick a rod in?

 

[Doomed]

I understand that it's a TT earthing system, but I dont understand the scenario described? If the earth between 2 hookups(for example the SWA isn't terminated correctly causing a 'poor connection') why stick a rod in?

'cos its corroded badley and I cant get anymore slack on them to make them off properly, ideally it would be easiest to leave that junction alone and sick a rod in.

On part 1 its 25 ohms between the source TT rod and the TNCS earth

 

[TJ Anderson]

I understand that it's a TT earthing system, but I dont understand the scenario described? If the earth between 2 hookups(for example the SWA isn't terminated correctly causing a 'poor connection') why stick a rod in?

Because you cannot use TN-CS for caravan sites so you have to convert to TT

 

[Doomed]

What Ra did you get for the rods and what test method did you use?

loop impedance test, everything disconnected from rod, 4 ohms, hence my worrys

 

[TJ Anderson]

loop impedance test, everything disconnected from rod, 4 ohms, hence my worrys

Don't worry that's great. Engineer 54 will be well proud of you mate, if it ain't single figure Ra it ain't worth having

 

[Leesparkykent]

I don't understand TBH, You are worried about having a good RA?