Setup
- Hub: C-7 Hub, platform 2.5.1.174, part of a 5-hub Hub Mesh, all C-7 hubs.
- Devices: two Enerwave ZWN-RSM1-PLUS relays (MSR 011A-0111-0605, firmware 5.12), no security, hardwired in a single gang box, controlling landscape lighting transformers
- Routes: West relay 01 → 1C → 88 at 100kbps; East relay 01 → 07 → 23 → 91 at 40kbps
- Drivers: Universal Z-Wave Switch through Oct 13, then Enerwave RSM1-Plus (erocm123) from Oct 14. I ran a Configure, and AssociationReport confirms group 2, node 1. The behavior was identical under both drivers. Even with group 2 linked, neither relay has sent an unsolicited report, including when the sunrise automation turns them off. Every state change appears only as a poll response.
- An automation turns the relays on at sunset and off after sunrise. For diagnosis, an automation polls both relays every 5 minutes overnight.
Symptom
Every night, one or both relays switch off on their own. The hub doesn’t log an off() command. The relays report off only when polled, and they never send an unsolicited report.
What the logs show (Oct 1–15, backup at the default 3:01am)
- Drops on 12 of 14 nights, always between 3:15 and 3:40am
- The 12 nights where the relays dropped, both relays stop answering refreshes starting around 3:05am, for 5–35 minutes, even though they use different routes
- When they answer again, one or both report off. The two relays drop independently, sometimes 15–25 minutes apart.
- The two clean nights were Wednesdays, when a Rebooter App commands a restart of all five hubs at 3:00am. So, the hub is in the reboot process when the scheduled nightly backup is supposed to be running
- I changed the automation so the relays would turn on 2 hours before sunset. The early activation changed nothing (drops still at 3:15–3:30), which rules out run time or heat
The test
I changed only the Entry hub’s backup schedule from 3:01am to 5:01am. The other four hubs kept their 3:01 backups.
Another data point: a backup at 10:03pm, created when I saved the schedule change, caused no outage and no drops. Only the scheduled nightly job seems to cause it.
What I’ve already ruled out: power-cycling the relays, Z-Wave repair, re-setting the lifeline association, no other loads sharing the circuit, run time or heat, and the device driver (same behavior on Universal Z-Wave Switch and the erocm123 Enerwave driver).
Questions
- What does the scheduled nightly backup or maintenance job do to the Z-Wave radio or stack on a C-7? Is the stack paused, restarted, or queued while it runs?
- Is there any known way this job could make a relay restart, or receive something that turns it off, without a logged command?
- Is this a known issue, and are logs or diagnostics from me useful?
For now, my workaround is moving the backup to a daytime hour when the relays are off anyway. I’m happy to run more tests.
