Heater power alarm problems

[Sleepydoc]

About a week ago I started getting multiple spurious alarms for my heaters. Since midnight, I have gotten 5 alarm notifications from Neptune stating "if Heater Output Watts<360 Then ON" followed by another e-mail a few minutes later stating "If Time 22:00 to 06:30 then OFF" Nothing changed in my programming that I'm aware of, and the heater was kicking in prior to this, so it wasn't due to the heater not being used.

Current setup:

• Heater alarm set up from the heater outlet Watts input configuration - Alarm when outside range, Minimum 360, Maximum 400.
• My alarm outlet has a statement "If Time 22:00 to 06:30 then OFF" almost at the end, followed by the leak detector statement so the only alarm notification I should be getting in the middle of the night is from the leak detector.
• The data log is set to every 10 minutes

Attached is a picture of the heater watts and the Heater outlet output. One thing I noticed on the graph is that the data points for the heater outlet output are not at the same times as the data points for the heater watts input. The heater watts take 10 minutes to ramp up on the graph, but I'm assuming this is more artifact caused by Fusion smoothing the graph to match the available data points.

Question 1: Why am I getting the alarm in the first place
Question 2: Why am I getting the alarm in the middle of the night when the alarms are supposed to be turned off?
Heater.jpg

[Sleepydoc]

A couple updates - First, I changed my logging interval from 10 minutes to 1 minutes. The greater resolution allowed me to see that the heater power actually was dropping below the alarm limit. This is a problem with the apex and troubleshooting alarms - the interval with which the controller checks/monitors the various inputs is much shorter than the logging and reporting interval, so you can get cases where an alarm triggers but it never shows on the reports. It would be nice if an alarm would force a log entry.

I have 3 heaters: 2 - 150W heaters and 1-100W heater. all are on the same outlet and in the same sump chamber with their internal thermostats set at about 82º to serve as a backup if the apex should fail. Looking at the graph, I noticed that the 100w heater would always turn off near the end of the heater cycle. I think what was happening was that as the water heated up, the water immediately around the heaters heated up enough to cause the 100w heater to shut off. I increased the temp and moved it further away from the others and the problem resolved.

The other change I made to reduce nuisance alarms in the future was I created a virtual outlet and programmed it to turn on only if the heater power is below 300W for more than 10 minutes and added that to my alarm programming rather than using the power programming from the inputs screen:

Set OFF
If Output Heater Watts < 300 Then ON
Defer 010:00 Then ON
Untitled.jpg

[sisterlimonpot]

I'm just throwing out an idea, unless I'm reading the graph wrong, the concern is with each individual heaters internal thermostat setting. When the Apex calls to turn on the outlet for your 3 heaters, the heaters haven't reached the set temperature to turn on yet. looks like each heater is slightly off to where a few minutes after the outlet is on the 100w turns on first followed by the two 150w ~15 minutes apart.

I would suggest turning the dials on each heater to change when the heaters should come on, that way the internal contact switch is already closed before the Apex calls for the outlet to be ON.

[Sleepydoc]

I think you’re reading the graph wrong - in second graph I posted, the orange is the heater power and the black/grey graph that you see stepping up is the water temperature. On the first two cycles, all 3 heaters come on immediately and the power goes up to ~380 watts, then right before they shut off you see the orange graph step down to 280 watts. In the 3rd cycle, you see a notch where the heater shuts off, then comes back on for a bit before they all get shut off by the Apex.

Historically, the thermostatic switches have been the primary failure point for heaters. They are typically a relatively cheap bi-metal switch that flexes completes a circuit to switch the heater on or off. With each cycle, a tiny bit of arcing occurs and eventually can cause the two contacts to fuse together in the ‘on’ position, meaning the heater never turns off and can over heat the tank.

The relay switch in a controller is typically better quality and less likely to fail, so I set the heater thermostats a few degrees above the set point for the controller. That way they are always ‘on,’ regardless of whether the Apex outlet is on or off. If for some reason the apex fails and doesn’t turn off, the heater thermostats will kick in if the tank gets too hot.

[CoralFan1776]

I think you’re reading the graph wrong - in second graph I posted, the orange is the heater power and the black/grey graph that you see stepping up is the water temperature. On the first two cycles, all 3 heaters come on immediately and the power goes up to ~380 watts, then right before they shut off you see the orange graph step down to 280 watts. In the 3rd cycle, you see a notch where the heater shuts off, then comes back on for a bit before they all get shut off by the Apex.

Historically, the thermostatic switches have been the primary failure point for heaters. They are typically a relatively cheap bi-metal switch that flexes completes a circuit to switch the heater on or off. With each cycle, a tiny bit of arcing occurs and eventually can cause the two contacts to fuse together in the ‘on’ position, meaning the heater never turns off and can over heat the tank.

The relay switch in a controller is typically better quality and less likely to fail, so I set the heater thermostats a few degrees above the set point for the controller. That way they are always ‘on,’ regardless of whether the Apex outlet is on or off. If for some reason the apex fails and doesn’t turn off, the heater thermostats will kick in if the tank gets too hot.

I would double check that the apex temperature probe hasn't drifted.
If it appears to still be accurate then it about has to be that the set point in one or more of your heaters has changed...