H F Posted February 4, 2020 Author Posted February 4, 2020 For the test, can I just remove the plastic caps and apply the terminals here. I just got a decent jolt trying to put one of the caps back on.., a reminder that I’m working with electricity.
PeterW Posted February 4, 2020 Posted February 4, 2020 3 minutes ago, Home Farm said: For the test, can I just remove the plastic caps and apply the terminals here. I just got a decent jolt trying to put one of the caps back on.., a reminder that I’m working with electricity. just push the multimeter pin inside the plastic from the top where the wires go in and the black one on the casing or the earth connector.
H F Posted February 4, 2020 Author Posted February 4, 2020 (edited) Red terminal on live (brown) cable, black terminal on casing and earth reads zero. Edited February 4, 2020 by Home Farm
H F Posted February 4, 2020 Author Posted February 4, 2020 Just now, PeterW said: And is that with the heating on ..?? Yes, the central heating (air source heat pump) is on, and all the underfloor heating thermostats are calling for heat. The Heatmiser central wiring box is also on with all the zones marked as on shown via little lit LEDs.
PeterW Posted February 4, 2020 Posted February 4, 2020 And you’ve definitely got a good connection to the brown wire ..?? Next stop is take off the cover on the wiring Centre ...
H F Posted February 4, 2020 Author Posted February 4, 2020 (edited) Yes, the connection was good. Can’t touch it because it zapped me earlier, but was a good contact - didn’t realise it would. Edited February 4, 2020 by Home Farm
Carrerahill Posted February 4, 2020 Posted February 4, 2020 (edited) 1 hour ago, Home Farm said: Red terminal on live (brown) cable, black terminal on casing and earth reads zero. Are you sure? You said you got a belt? To get a belt something must exist... On your PCB I can see marked zones, which zone is this valve on - are you getting 240 across live and neutral on the board and the respective zone terminals? The next thing I would then do is confirm that the other end of that wire, i.e. at the valve is delivering power - which I think it will be given you got a jolt. Could wire damage be present anywhere? A damaged neutral/earth but an OK live would result in 0V across the 2 wires yet still very much live! Edited February 4, 2020 by Carrerahill
dpmiller Posted February 4, 2020 Posted February 4, 2020 and the meter is set to VAC, not DC correct?
H F Posted February 4, 2020 Author Posted February 4, 2020 Metre is on V. This is interesting. On 2, 20 and 200 it reads a battery at 1.5V. On 600, it reads zero. Is the meter broken?
H F Posted February 4, 2020 Author Posted February 4, 2020 (edited) Photo of metre settings - just showing how it’s set when I tested it. Edited February 4, 2020 by Home Farm
dpmiller Posted February 4, 2020 Posted February 4, 2020 It's V (squiggle) 600 you need, round to the right.
H F Posted February 4, 2020 Author Posted February 4, 2020 Success, despite a shot of bourbon and didn’t shock myself again. Reading was 246.
H F Posted February 4, 2020 Author Posted February 4, 2020 4 minutes ago, dpmiller said: It's V (squiggle) 600 you need, round to the right. So when working with home electrics, do I stick to the right? 600 and 200 V (squiggle)?
H F Posted February 4, 2020 Author Posted February 4, 2020 So why did I have to use the squiggle for this test?
H F Posted February 4, 2020 Author Posted February 4, 2020 Pertaining to my test, have we now identified that the motor on the valve needs replacing?
dpmiller Posted February 4, 2020 Posted February 4, 2020 14 minutes ago, Home Farm said: So why did I have to use the squiggle for this test? Because mains electric is Alternating Current. The V (dash dash) is Direct current, you'd use that around a car or to test batteries etc. 1
Ed Davies Posted February 4, 2020 Posted February 4, 2020 3 hours ago, dpmiller said: Because mains electric is Alternating Current. The V (dash dash) is Direct current, you'd use that around a car or to test batteries etc. Adding a bit more detail for background: on the AC range the meter will sample over the whole waveform and take an average which best represents the overall voltage, both positive and negative. Effectively it squares the individual voltage samples (so both positive and negative come out positive), averages those, then takes the square root. This is called the RMS value: root mean square. Our standard 230 V AC peaks at about 325 volts but the meter shows the average magnitude of 230 V, or whatever, not the peaks or overall average which is obviously zero over periods much longer than a 1/50th of a second. On the DC range it just takes samples and displays those, probably with a bit of averaging so it's likely that the AC will average out to zero. 1
H F Posted February 5, 2020 Author Posted February 5, 2020 Ok. We’ve determined that power is getting through to the live cable. I took the motor off, and switched off all call for heat from all thermostats. my wide then turned it on while I watched the motor and the spinny thing on the back of the motor is not turning. I waited for a minute. Fair assumption that it’s the motor that needs replacing?
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