Reply
 
Thread Tools Display Modes
Old 10-12-2019, 02:23 PM   #1
NXR
Senior Member
 
NXR's Avatar
 
Join Date: Mar 2019
Location: Family room couch
Posts: 497
A caution on the Precision Plex holding tank and elbow heater system

It's going to get into the mid to low 30's so I went to turn the Tank Heaters on using the Precision Plex touchscreen. The touchscreen is displaying this message:

Tank Heater Enabled, will turn on if voltage > 13.2 V

Unfortunately the Precision Plex touchscreen is displaying its usual 13.1 VDC reading on the "Levels" screen. The Xantrex inverter panel above the touchscreen says the house battery voltage is 13.0 volt.

I sent an email to the support address for Precision Circuits and they responded with their usual almost immediate response. Excerpts:


I presume the 13.1 VDC reading means that if it had gotten down to freezing last night that the tank and elbow heaters would not have powered up.
Correct


Is there a way to decrease the minimum house battery voltage needed before the tank heaters will turn on?
No

The Voltage was not selected to ensure the batteries did not go flat. It was selected to only allow operation when RV was plugged in and charging.

As far as I know, minimum charging voltage should be 13.3V. So that is the reason for our 13.2V threshold. Again, you may want to check with the Battery Charger company.


The root problem is there is a mis-match between how the Precision Plex Tank Heater system is programmed and how the Progressive Dynamics PD9270 Converter/Charger is programmed.

The PD9270 is designed to go into "Storage" mode if there has been no significant battery usage in the past 30 hours. The "Storage" mode voltage is 13.2 VDC, not the 13.3 VDC that Precision Circuits believes is the minimum.

The PD9270 manual: https://www.progressivedyn.com/wp-co...1F-english.pdf

The attached pictures are from that manual.

The only workaround I can think of is to shut off the shore power breaker and draw down the house batteries for a while, although I have no idea what "no significant battery usage" means to Progressive Dynamics. That should take the charger out of Storage mode for the next 30 hours.

I'm asking our dealer to open a warranty ticket with Forest River but I think Ohio will freeze over before any fix is issued.

Ray


PS: I also asked this question since it's a related topic:

Will turning the on the Tank Heater damage anything if the "Warning: Low Water Level" message is being displayed? Is the tank heater inhibited if that tank level is too low, are all tank heaters inhibited, or is it just an advisory message?

Not sure, we do it differently for different RV’s but if it turns on it should give you that feedback.

Yes, if there is no water, and Tank Heater is turned on, depending on Heater strength and actual air temp, there could be damage.
Attached Thumbnails
Click image for larger version

Name:	PD9270 Graph.PNG
Views:	15
Size:	149.8 KB
ID:	217123   Click image for larger version

Name:	PD9270 Modes.jpg
Views:	15
Size:	131.5 KB
ID:	217124  
__________________

__________________
2020 Georgetown GT5 34H5
NXR is offline   Reply With Quote
Old 10-12-2019, 04:22 PM   #2
NXR
Senior Member
 
NXR's Avatar
 
Join Date: Mar 2019
Location: Family room couch
Posts: 497
OK, I took the easy way out. I shut off the shore power breaker and took the dogs for a 35 minute walk while leaving lights and the inverter on. The house batteries were down to 12.1 VDC when I flipped the shore power breaker on and now the touchscreen is showing the hoped-for 13.6 VDC and slowly climbing.

I probably could have just shut the shore power off and also shut the house batteries off for a much shorter period of time to drop the power to the converter/charger and done the same thing. That will be the next experiment.

Tonight is the only night it’s getting that cold.

Ray
__________________

__________________
2020 Georgetown GT5 34H5
NXR is offline   Reply With Quote
Old 10-14-2019, 06:39 AM   #3
Junior Member
 
Join Date: Oct 2019
Location: OHIO
Posts: 4
Wow that's interesting! I guess I'm glad I don't have a touchscreen to control everything, just old-fashioned on/off switches on our 2019 XL369. With all the LED lighting they install in these new RV's my converter very rarely kicks into charging mode, It mostly stays in maintaining at 13.1-13.2 volts. I can see how what your saying could be an issue, sounds like they need to do some reprograming of there control software...
H3OHIO is offline   Reply With Quote
Old 10-14-2019, 11:50 AM   #4
NXR
Senior Member
 
NXR's Avatar
 
Join Date: Mar 2019
Location: Family room couch
Posts: 497
Agreed. I asked the Precision Circuits support person to try and get this issue addressed with Forest River. Today is the first work day since I found the problem so obviously I do not have an update on that yet, and today is a holiday for some companies.

Right on schedule, the PD9270 converter/charger kicked back into Storage Mode just after midnight. It was only supposed to go down to 40 last night so I wasn't worried about freezing, plus I had turned the tank heaters on earlier in the evening to build up some heat in the water mass.

While the house battery voltage was at 13.1 VDC when we awoke this morning, interestingly, the touchscreen indicated that the tank heaters were turned on and the Tank Heater screen message said voltage was 13.5 VDC when the voltage clearly was lower. It looks like that is a static message that does not change once the heaters fire up.

I turned the Tank Heater off and back on and now the message says they will turn on when the voltage gets greater than 13.2 VDC. So hopefully this means that the voltage check is only done when the Tank Heater function is selected to On and only a factor until the battery voltage rises.

The other possibility is that the Precision Circuits controller does cut the tank heaters off if the voltage drops but the touchscreen message does not reflect that change. If that is the case then someone could get fooled into thinking they were protected when they are not. Based on one email response, I do not believe that is the way the system works but I am not certain.

UPDATE: Since it's going down to 35 tonight and since the PD9270 is in Storage Mode and showing 13.1 VDC on the Precision Plex touchscreen, I just killed the shore power to the coach and shut the house batteries off for one minute instead of trying to draw the battery voltage down by running stuff. Yes, the PD9270 converter/charger did reset and the touchscreen now shows the house batteries are at 13.5 VDC and the Tank Heater screen confirms that the heaters will turn on.

There does not appear to be any way to disable Storage Mode manually, even with their optional remote pendant, but this method does work. As long as I remember about the need to do it.

Ray
__________________
2020 Georgetown GT5 34H5
NXR is offline   Reply With Quote
Reply

Tags
heater, tank

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



» Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by Forest River, Inc. or any of its affiliates. This is an independent, unofficial site.



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 05:05 AM.


×