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Hello,
I have two pieces of Morningstar Tristar MPPT-60A and one battery. I am a
bit confused how to connect/set them together to work as a team. Both
tristars are connected over ethernet into router, I can read/write all
parameters via MSView from both of them. They have absolute identical
settings except of IP adress and Modbus ID.

Is there any way to force the first one to work like master (measure
voltage, temperature, manage charging phases MPPT,absorp,float,..) and force
second to just take these values and charge in accordance to them?

Why? Due to manufacturing tolerances of both RTS sensors they see different
temperature at battery (+-2°C) and thus have slightly different compensated
charge voltage (and they also measure slightly different battery voltage) >>
one goes float while other tries maintains absorption.

Could it be done simply over ethernet (by setting some special parameters in
MSview) or is this only possible through MeterBus Hub-1 ? I can't find any
"idiotenfest" instructions either in " TriStar MPPT Operators Manual " or "
Tristar/Tristar MPPT Bridging Redundancy " or "Morningstar Communications
Document".
Thank You

Hello
Are the two TS-MPPTs connected to one array? If so, this is the problem;
there are sweeping and other coordination issues. Following is a Tech Note
on this subject:

With one array for each controller, there is complete flexibiltiy -- no need
for blocking diodes, and multiple MPPTs, PWMs, or any combination can be
used. With only one array, an MPPT unit must be used alone. Using one
arrray, any number of PWM controllers can be connected in parallel, but the
maximum array current cannot exceed that of the lowest rated controller in
the system. Further, blocking diodes are always required on each controller'
s PV (+) wire to allow proper night-time detection, which is used to prevent
reverse current leakage.

Regards
Gerald

Sorry I forgot. Each Tristar has its own solar array. Everything works fine
except of temperature compensation. I'll try to explain:

Both RTS sensors are mechanicaly tied together so they could measure same
temperature at battery. But at image "Tolerance RTS.JPG" you can see they
read different temperature and the difference further at graph is 23°C vs.
25°C . One Tristar then compenstes for 23°C while other thinks that same
battery has 25°C . Compensation is set to 3mV/deg/cell, so at 2°C difference
there is 240mV target voltage error, see at "DiferenceTargetVoltage.JPG".
Tristar that is reading 25°C then practically takes lead and leaves other
one in dust - it is charging almost at current limit 60A while other one
cannot push more than few Amps.

Is there any workaround? Or do I need to buy meterbus Hub-1, will it solve
sychronization of target voltage?

Each controller requires its own separate RTS. The sensors are
based on resistance; combining them creates inaccuracies, and the conflict
could be causing the problem. Thank you. Gerald MSTS

I am afraid I wrote it inaccurately. I am electrical engineer as well and I
know that paralleling NTC thermistors would cause trouble. RTS sensors are
electrically isolated, they are just screwed together to insure same
temperature of metal case. I know they are manufactured with some tolerance
and that is the reason of different temperature read at Tristar MPPT. All I
want to solve is synchronization of "target voltage". Studer Variotrack
could be easily synchronized with RJ45 cable, Outback uses their Master-
Slave synchronazation, even cheap chinese MPPSolar PCM regulators could be
synchronized to work as a team.

Is it possible to connect two Tristar MPPTs to be synchroized and charge
like one 120Amp controller? Do I need meterbus Hub-1?

Thank you for you patience.

We apologize, but we are just developing sync capabilities for these
products; currently, our customers with similar configurations - sometimes
more than 10 units - use battery sense connections, and set up wiring and
arrays as identically as posssible. Then, the controllers are started
simultaneously.

The Meterbus Hub is used to allow metering for multiple devices on one
network.

Regards

Thank you for your honesty. Otherwise your products are excellent and among
top of market. Keep on doing your good work.

Foxxx píše:tak to je velice škoda... Na netu sem našel fotky kde mají např. i několik tristárů zapojených podlě mě na jedno bat.pole. V tom připadě to ale znamená že každý rve do baterky co to dá ??? jakoby tam byl sám ?

Foxxx píše:tak to je velice škoda... Na netu sem našel fotky kde mají např. i několik tristárů zapojených podlě mě na jedno bat.pole. V tom připadě to ale znamená že každý rve do baterky co to dá ??? jakoby tam byl sám ?

kybos píše:

Foxxx píše:tak to je velice škoda... Na netu sem našel fotky kde mají např. i několik tristárů zapojených podlě mě na jedno bat.pole. V tom připadě to ale znamená že každý rve do baterky co to dá ??? jakoby tam byl sám ?

Ano, je to tak, každý paralelně připojený Tristar se chová jako by byl k baterii připojen sám. Výsledek je ten, že zatím, co některé připojené nabíječe už mají float, jiné se sveřepě snaží nabít baterii na své "Target Voltage" dle svých "Battery Sense Voltage", a pokud jim to nastavený proudový limit povolí, také se jim to při dostatečném výkonu svěřené části fotovoltaického pole povede bez ohledu na ostatní (ne)spolupracující nabíječe.

mypower.cz píše:Urcite by jim slo rict aby daval kazdy z nich max 40A, pokud mame 2 vetve panelu a obe dokazou ve stejny okamzik dat vice nez 80A kdy kazda z nich umi dat >40A osamote. V tom pripade limit 80A by nemel byt prekrocen nikdy.

kybos píše:Zadávat proudový limit nižší než odpovídá maximálnímu výkonu FV pole znamená.....

atom píše: Baterie jsou u ostrovních systémů nejdůležitější.

atom píše:Jde o to jak si kdo takový výstup na přebytky představuje.