Fm80 - T100

Re: Fm80 - T100

BRJ,

I will perhaps use one of the following modules:
http://www.schottsolar.com/uploads/m...8-81-86_en.pdf

At moment it is not easy to get modules in Germany. With the FM80 I can make 6 modules serial in one string. Nominal voltage is about 100volts. Open circuit voltage will be about 136V.

PV module specs are based on a cell temperature of 25 C. When the modules are colder, the module voltage will increase. For example, here in the U.S. we use a standard multiplier of 113% for ambient temperatures down to -10 C, and 125% for ambient temperatures down to -40 C Ref NEC 680-7).

At -10 C, the temperature corrected voltage specs would be ~113 V and ~154 V. The latter value is higher than the FM80’s limits (145 V operational and 150 V absolute maximum), so the six modules in a series string is not a good idea. I’d recommend a maximum of five modules per series string.

3 strings makes about 1450W nominal power. Is the initial power of 1800W not to high for the MX60?

The MX60 is factory rated for a maximum 1,600 W STC PV array for 24 V battery systems. However, the controller’s output current setting can be increased from 60 A to ~70 A (see “Charger” menu), and, unofficially, I’ve heard of ~2,000 W arrays being used with the MX60 and 24 V batteries. But, it’ll likely run a bit warm, so a spare cooling fan or two would be a good idea.

I think a cable with 25mm² is for 50m necessary. What is your opinion?

Assuming that the array is ~50 meters from the controller, the total wire length will be 100 m (328 feet). Assuming a 1,600 W array configured for “60 V” nominal (~80 Vmp), the maximum operational current will be ~20 A. Assuming a maximum voltage drop of 1.5%, you’ll need “3/0” wire (~85 mm2).

Reference: FM80 and FM60 User Manual ( http://www.outbackpower.com/pdfs/manuals/flexmax.pdf )

With FM80 it is possible to make later 4 strings.

The FM80 is rated for arrays of up to 2,500 W STC with 24 V battery systems.

I found prices for MX60 about 490 USD and for FM80 about 570 USD in USA. In Germany they cost 980 USD and 1100 USD. Why do they cost here so much more?

U.S. prices typically do not include shipping or local taxes. I suspect that European prices include shipping to Europe, import duty, and local tax.

What should be all in the combiner for this system? circuit breaker… overvoltage protection (lightning)? grounding lug

PV array combiner boxes typically include circuit breakers. See information on the OutBack FlexWare PV combiner boxes and DIN-mount DC rated PV array circuit breakers for more info: http://www.outbackpower.com/products/integration_hardware/flexware_pv/
http://www.outbackpower.com/products/integration_hardware/system_components/

OutBack’s combiner boxes (and controller and inverters) include grounding lugs. System grounding should be carried out according to local electrical standards.

Is the circuit breaker enough for lightning?

Probably not. Again, check local standards. The OutBack controller’s contain limited lightning protection (MOV’s). External lightning arrestors are recommended. See: http://store.solar-electric.com/deliar.html

The difference between MX60 and FM 80 are voltage and amps. Anything else?

The main differences between the MX60 and the FM80 are:

MPPT algorithm: periodic sweep vs. continuous tracking
Output current: 60 A vs 80 A
Ambient temperature: 25 C vs 40 C for full power
Operational Input Voltage: ~141 V vs. 145 V
Remote Programming: no vs. yes (via Mate)
Data Logging: 64 days vs. 128 days

Note that MX60 production has been discontinued. It has been replaced with the FlexMax 60, which is the same physical size as the legacy MX60, and is still rated at 60 A output, but otherwise offers all of the features of the FM80. See here for more information: http://www.outbackpower.com/products/charge_controllers/flexmax/

I hope this additional information is helpful to you.

Regards,
Jim Goodnight
“crewzer”
Eastern Regional Sales Manager
OutBack Power Systems