Leopard01

A little off-topic, although I have been wondering about the relationaship bewtween the TSE1 display and the controller. I understand that for PV heating of the geyser one needs the Solar Eco MPPT. This MPPT gets its input from either the secondary (P2) or primary (P1) PCB ports (3 cables, Display+Thermo+Signal to MPPT) of the controller. I assume, the signal is the same used for the pump, being triggered with the Thermo signal and the programming open the circuit. The TSE1 controller takes 220V AC converting some of this via a transformer to 5V (first stage approx. 9V), I seem to recall. But, there is no backup power for the TSE1 controller, afaik. Is this correct? Any solutions for backup pwr to the TSE1? The Gyserwise Max, I understand, has a backup power solution for the controller and pump system. But, I recall being informed that it does not control PV power like the ECO MPPT. Correct? TSE1 problem 1: For a non-ECO MPPT battery charger (or other brand). Running a controller P1 signal cable to a 3-5V DC relay mounted to the DCB could be all that is needed to turn PV pwr on/off per the controller programming. Comments? TSE2 problem 2: Backup power to the controller. I notice the use of PCB transistors and mosfets. Assuming their is no feedback current after the voltage drop to 5V. Could mounting a rechargeable NiMH PCB (9V in, 5V out) in parallel not resolve this issue? Better still, disrupt the voltage drop to 5V, and have it supplied solely by the NiMH PCB? Finally, I have noticed that there are a few direct PV to Geyser MPPT controllers (no battery charger) which do what one wants without installing a PTC AC/DC element. They work with standard geyser hardware. Firstly, the one I read about, uses PV DC to AC "modified sine" viz. it is a hybrid of either MPPT (or PWM) with a modified sine inverter. Secondly, it is more expensive for a dedicated solution which might not be justifiable because modified sine inverters are cheaper to manufacture than pure sine. Thirdly, resistive loads and inductive loads afaik work differently. The current to the inductive load gets less as temp increases, therefore safer should there be a thermostat failure in the closed state. Fourth, you could achieve the same control with PV to a 20-70V DC 1800W buck booster PCB to PTC DC element, some relays and a DC digital timer (if you must). Concerning the fourth point, I will be doing this and using the Geyserrwise TSE1 to disrupt PV power via a relay (perhaps arduino). There is also a wifi upgrade to the TSE1 display now. The alternative would be to install the Geyserwise ECO MPPT. If you have wrestled with similar problems and found solutions or difficulties, pls post.

Hi, Good to know the Geyserwise controller is not dependent on AC pwr. The MPPT solar controller connects directly to the PTC element. This means that your MPPT must deliver output Voltage (Amps, P=IV) to match the demands of the PTC. The controller takes a 12V, 2-4Ah batt. for backup power for the controller and display unit. I assume the controller and display unit would otherwise be powered by AC 220V, the internal transformer converts to AC to necessary DC. According to the programming, the controller will either use DC from the MPPT solar array or AC when there is no MPPT power. Now, MPPT load is taken from the batteries, not sure if this is only when there is no solar. My MPPT has settings to run the load 24 hrs, cut the load at low PV voltage, etc. Ideally, I want my MPPT to feed PV current direct to the PTC during daytime hours only. The MPPT jsut keeps a small battery array charged which I can use for some after hours or emergency power, independent of the MPPT load contacts. I have no experience of the Geyserwise MPPT unit, tho'. Hope I have a correct understanding of the Geyserwise setup for PTC elements.