Fault finding with Fluke 116 DMM

[knuckles]

Hello, I have installed an oil boiler to a property and wired up the controls according to the MI's.
When I turned on the permanent live to the boiler, the power light came on. When I put a demand on the boiler from the porgrammer, the burner demand light came on, but nothing else happened. No pump, no fan.
I set my Fluke to Auto Volts and upon tresting between the switched live input on the hot water and the boiler casing. The main RCD tripped.

Is there a fault with my wiring or should I use the DMM on a different setting? I've used plenty of DMM's in the past but I only bought this last week.

 

[Spark123]

It appears to be a LoZ (Low Impedance) range, i.e. the meter takes more current to eliminate measuring a voltage caused by capacitive coupling etc. This is probably why the RCD tripped.
A high impedance range shouldn't cause the RCD to trip but can measure stray voltages which have no current behind them.

 

[Monkeh]

Yes, the auto volts position on the 116 is a low impedance setting. You will actually have to know if you're measuring AC or DC for this one!

You may also try not measuring between line and earth on a 30mA RCD protected circuit with a meter with 3 kΩ input impedance.

 

[flameport]

When I turned on the permanent live to the boiler, the power light came on.
When I put a demand on the boiler from the porgrammer, the burner demand light came on

I set my Fluke to Auto Volts and upon tresting between the switched live input on the hot water and the boiler casing. The main RCD tripped

All of that is exactly what you would expect to happen.

As for the boiler not working - more likely to be some issue with the boiler itself, such as built in timer/programmer/other control not set correctly, or some installation/commissioning procedure has to be done first, or it has no fuel, no water, no pressure, etc.

 

[Monkeh]

When I turned on the permanent live to the boiler, the power light came on.
When I put a demand on the boiler from the porgrammer, the burner demand light came on

I set my Fluke to Auto Volts and upon tresting between the switched live input on the hot water and the boiler casing. The main RCD tripped

All of that is exactly what you would expect to happen.

If you've read and understood the manual, anyway.