by ericmark »
Tue Feb 15, 2011 11:55 am
What ever tester you buy there will be a better one and a cheaper one. You have to decide the compromise between quality and price. However if you are fitting a RCD be that stand alone or as a RBCO then you need to test it. Also although one can find out the earth loop impedance by inquiry and calculations one would normally use an earth loop impedance meter and also you need to know the prospective short circuit current.
It is therefore normal to get all three meters or an all singing dancing meter to do all the required tests not just a few selected tests.
The all singing dancing meters tend to also have the ability to test earth rods where the set of three often does not have that feature. But of course if it goes wrong you have lost all three.
Often firms select meters able to do things like store and down load results. That way the users can't cheat but for a one man band that is not a problem. However some of the computer driven software inside the meters can slow them down.
For a single job to borrow or hire would seem best option. That way you can try out at least one type and see how you like it. Talk to local supplier they will often let you try out a meter before buying from their hire stock. Often hire price knocked of meter price just to make sure you and not just hiring for free.
On the second hand market it is really down to what is available.
As to the consumer unit. If altered it is no longer a consumer unit. The name consumer unit is given to a type tested distribution unit and to comply with the type testing it must be as designed by manufacturer.
Then of course we have Part P to contend with and their command of English seems lacking and to work out what is meant by like for like replacement is anyone's guess but I am sure renewing the guts of a consumer unit will not comply without paying the £100+ for passing go.
If you are at college ask the guys you do the course with what they use and how they find them. Not had a problem with Megger gear or Robbins. However had big problems with Siemens test gear. But maybe I was just unlucky. Even the cheap clamp on I bought in Hong Kong just before take over is still working well so price and reliability don't seem related.