60 Cell panel VMP

mcgivor
mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
in Solar Skeptics, Hype, & Scams Corner #1
Looking for panels I came across some 250W 60 cell with the following specs.
 Manufacturer Zhunyan
 Polycrystalline 

P max                          250W
Voc                               43.2V
Isc                                 7.72A
Vmp                              36v
Imp                                6.95A
Sys V  1000V
Power Tollerance       +/- 3%

What stood out is the Vmp, from all the information I've researched, 60 cell panels are usually in the 30-30.4v range and are not recommended with PWM controllers, but with these? Could be those smaller Chinese volts, watts and amps like the legendary Powe Jack contraption uses, who knows  . Google comes up with nothing for Zhunyan. 
1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
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Comments

  • bill von novak
    bill von novak Solar Expert Posts: 891 ✭✭✭✭
    #2
    mcgivor said:
    Looking for panels I came across some 250W 60 cell with the following specs.
     Manufacturer Zhunyan
     Polycrystalline 

    P max                          250W
    Voc                               43.2V
    Isc                                 7.72A
    Vmp                              36v
    Imp                                6.95A
    Sys V  1000V
    Power Tollerance       +/- 3%

    What stood out is the Vmp, from all the information I've researched, 60 cell panels are usually in the 30-30.4v range and are not recommended with PWM controllers, but with these? Could be those smaller Chinese volts, watts and amps like the legendary Powe Jack contraption uses, who knows  . Google comes up with nothing for Zhunyan. 
    My first assumption would be that Zhunyan has no native English speakers who could draft a new label, so they copied it from someone else's 72 cell panel label.
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  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
    #3

    Hi mcgivor,

    Agree that this is a bit suspect,  especially for Poly PVs.   There are some 60-cell PVs with Vmps in the 33-ish range,  but believe that these tend to Monos.

    Would bet that you would want to have the manufacturer confirm all of the spec values.  If one divides the 250 W by the stated Imp,  one does come up with 35.97 Vmp.

    Also,  the stated Power Tolerance if +/-- 3%.   Most name-brand manufacturers have gone to,   --0 - + 5W,  or similar.

    If you must buy these PVs I would,  at the very least,  write a Purchase Order,  stating the conditions of acceptance by you ...  although,  perhaps where you are,  such a document might have no standing,  in reality.   Also,  using the Standard  Flash Tube measurement,  is very,  very difficult for the average customer,  in the field.

    IMO,   Vic

    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
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  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    #4
    Don't think I would consider them when the manufacturer seems to not exist, there are better choices with names recognized by Morningstar's array caculator, all the panels I currently have are Schutten and so far so good so will stick with those.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
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