Fault Finding with Continuity Tester Only!

[whazza2]

Would like some advice/methods for dead testing:

Central Heating System

Ring

Radial

Lighting

CO2 Detector

3 Phase Motor

Can only use a continuity tester to locate faults.

Thanks

 

[Andy™]

i assume this is for AM2/other test?

in which case the faults are mostly open circuit or crossed. its simply a case of making sure each cable goes from one point to where it should, and not open circuit, or somewhere else

 

[whazza2]

Yeah it is, im worried about finding faults with the central heating system as there is so many components

 

[Andy™]

dont know how they do it with the new AM2, but on the older, they had a switch board what could only corss wires/open circuit. there isnt much else they can do, and not much else you would be able to find with only a continuity tester

 

[sparkytim]

Hi

Just remember the basics, to prove a circuit you should have continuity between all points interconnected with conductors shown on the drawing, so you connect one lead of your meter to one terminal and the other lead to the terminal shown as connected to the first and you should have a LOW ohm reading. If its >999 ohms or similar then you have an OPEN circuit (break in the conductor under test)

So for instance the drawing may show a conductor going from the Programmer terminal 3 to the Room thermostat terminal 1 test between the terminals show on the drawing to confirm that it does.

Remember to Zero your test leads before you start to prove it is working.

 

[Evans Electric]

By continuity tester I assume you mean an ohm meter and not just a bell set.

For a 3 Phase motor all you can do is check that each of the 3 windings has the same reading end to end, then test each to earth .

Central Htg , test that the wires go where they are supposed to go but beware of back feeds : ie: mind the neutral on the stat doesn't give you a false reading etc.

 

[a1spark]

Wow !

Glad I was pre-AM2 Apprentice

 

[whazza2]

How would you find a short circuit using a continuity tester?

 

[Andy™]

continuity between 2 conductors that should be seperate

 

[whazza2]

So a fault being "MCB trips when heating sensor is called" would indicate a short circuit between the sensor and programmer (or wherever those cables go)?

 

[whazza2]

Fault: "No insulation reading on carbon dioxide detector" ( would that also be a short circuit)?

 

[kme]

I would say so - although "technically" you cannot have " no reading". There is ALWAYS a reading - you can`t always measure it