Bypass / Blocking Diodes
Here is the situation: I have 2 roof top panels (95W GoPower, Imp 5.53, Vmp 17.2) mono and a 100W Windy City (Imp 5.75, Vmp 17.4) poly panel wired in parallel on the roof. No room for more. For l...
Forum Discussion
So you have seen the same result whether the portables are connected to the input of the controller with their internal controllers bypassed or with them connected to the battery side of the controller with their controllers in play, but only when the GoPower is in float?
Is the current output you mention actual solar output or what is going into the batteries? (not necessarily the same thing) If the Trimetric is configured in the usual way it only registers what is going into or out of the batteries. Any other load is not seen. The importance of this is as follows.
It sure sounds as if one of the 80w panels is faulty and dissipating power rather than producing. However I can't see how this happens only at float voltage.
I assume you have tried disconnecting them when the system is not in float to see what happens? It would be worth it to put a volt meter across the panel leads and verify each panel output. If one has a voltage output less than system voltage it will dissipate power in the absence of blocking diodes. So the scenario is your total solar output (in float) is ~ 2 amps. With the (possible faulty) panels disconnected all of it goes into the batteries. When the panels are connected, one of them is dissipating ~ 1.5 amps and .5 amps is going to the batteries. This could happen without a measurable change in system voltage.
If it is a panel failure, maybe it is related to panel temp and only occurs when the panel reaches a certain temp. When you plug it back in in the late afternoon and the panel is cooler, it functions normally.
Those more knowledgeable than I may shoot holes in this but it seems to be the only scenario that fits.
Is the current output you mention actual solar output or what is going into the batteries? (not necessarily the same thing) If the Trimetric is configured in the usual way it only registers what is going into or out of the batteries. Any other load is not seen. The importance of this is as follows.
It sure sounds as if one of the 80w panels is faulty and dissipating power rather than producing. However I can't see how this happens only at float voltage.
I assume you have tried disconnecting them when the system is not in float to see what happens? It would be worth it to put a volt meter across the panel leads and verify each panel output. If one has a voltage output less than system voltage it will dissipate power in the absence of blocking diodes. So the scenario is your total solar output (in float) is ~ 2 amps. With the (possible faulty) panels disconnected all of it goes into the batteries. When the panels are connected, one of them is dissipating ~ 1.5 amps and .5 amps is going to the batteries. This could happen without a measurable change in system voltage.
If it is a panel failure, maybe it is related to panel temp and only occurs when the panel reaches a certain temp. When you plug it back in in the late afternoon and the panel is cooler, it functions normally.
Those more knowledgeable than I may shoot holes in this but it seems to be the only scenario that fits.
