Here again with a silly question regarding relays; I hope the experts can help answer it
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The simple schematic of the live-side of the relay at the installation site is as follows: 24v+——————Terminals 5 and 9 of the relay (i.e., the normally open contacts)——————Coil of the on-site solenoid valve——————24v-. Why can’t a multimeter measure 24V across terminals 5 and 9 when the contacts are not closed and the relay is mounted on its base? When the contacts are not closed, remove the relay from its base; at this point, using a multimeter to measure terminals 5 and 9 shows a voltage of 24V. I think in both situations there should be a voltage of 24V – why can it be measured in the latter case but not in the former?
Then check whether the relay contacts are closed
The contacts of relays 5 and 9 are not engaged – that is, the relay coils are not powered. If you measure 5 and 9 directly, is there any difference compared to when the breaker is turned off? If the relays and solenoids are working properly, it is likely that the measurement was not done correctly.
The phenomenon is truly strange; I’ve measured it several times, and the result is always the same. I really can’t figure it out
It’s definitely not closed; the coil isn’t getting power, so the light doesn’t turn on
If a voltage is measured between 5 and 9, it means the relay definitely has not engaged.