"High" Earth Loop Impedance on potential house pur

[caravanboy]

I am considering moving house shortly. An electrical report supplied by the vendor (from 2009) has a note from the electrician saying something about the "Earth Loop Impedance" being too high (I think it said 0.58ohms). There are also copies of follow-up letters from the local distribution company (YEDL) indicating that this is "normal" due to the design of their network in that area.

The house is a fairly isolated 4 bed detached farmhouse style property (about half a mile from the nearest other houses) . It has a single-phase "PME" supply. My surveyor indicated that the main consumer unit is probably less than 5 years old. Other than the usual cooker, lighting, and socket circuits there appears to be a larger separate outdoing circuit from the consumer unit (via a single 60amp switch) to a smaller consumer unit in an annex.

Can anyone help with these questions:

1) Is this high reading anything I should worry about really and what are the day-to-day implications (if any)?

2) Is this issue likely to restrict anything electrical I would want to do with the property in future? For example:

a) install solar panels

b) fit a large heat-pump (max size that would work on single-phase supply)

c) install a power supply to a new external workshop

Thanks in advance,
Shaun.

 

[flameport]

While 0.58 might be 'too high' compared to the widely overused and assumed maximum of 0.35 for that type of supply, it certainly won't be causing any problems for a typical house.

For the items suggested:
a. Solar panels require a tiny little connection, since they will produce tiny little amounts of power and are generally a waste of money and resources.
b. Heat pumps are generally soft start now, so no issues there. Even if not, a single phase model won't be powerful enough to cause issues.
c. No problems with power to a workshop, unless it contains completely unnecessary and dangerous items such as an industrial sized Xray machine, a particle accelerator or a laser capable of burning through things , however that isn't too likely.

With regards to buying the property, it isn't an issue at all.

 

[securespark]

It may be a TT to PME conversion, in which case I know that UU round here have higher tolerances for the Ze than they do on "true" PME supplies.

 

[PrinceofDarkness]

That reading is nothing to worry about for such an isolated property.

The much quoted figure of 0.35 Ohms was only ever meant as a 'typical' value for 'average' properties - it is by no means a 'guaranteed' value and should never be taken as such.

I would be quite content with such a reading in a rural setting.


Lucia.