Replacing a broken panel - Critical Specifications

ghostofthenorth

Hi all, its been a while since I've posted, but as usual I appreciate the wisdom in the forum!  I've searched through the site and can't find complete answers to some questions:

I have 2 arrays at my house that are grid tied.  Each has its own inverter tied to the grid.  One of the arrays has a broken panel which was working well until a torrential downpour recently.  It seems that some water was able to get through the broken glass and short a connection to the frame, which is grounded.  This caused some burning, and even melted some of the glass!  This caused a ground fault in the inverter, which shut things down.

The issue that I have is that this is an old panel from a company long out of business.  The panel is made by Arise Technologies Corportation, part number 010AR210WF1.  I can't find one anywhere and want to replace the broken one in the string.  My question is; what are the critical specs that I need to match (exactly or close) when replacing the panel?  The physical dimensions would ideally match, but I have some play, this panel is at a corner of the array.

Rated Power Pmpp: 210W
Classification Range: +- 5.00W
Rated Voltage Vmpp: 28.36V
Rated Current Impp: 7.42A
Open Circuit Voltage Voc: 35.94V
Short Circuit Current Isc: 8A
Max Sys Voltage Vmax: 1000V 
Series Fuse: 15A

My assumption is that Vmpp and Impp are the most critical, but I do not know this for sure.  Also don't know how close is close enough...?

Any and all help is greatly appreciated!!!

BB.

As you found--Cracked glass panels do not survive very long in the weather... Sorry to hear about the broken panel.

You are correct, matching Imp and Vmp is the important part here. And need a little bit more information about your array (number of panels in series, number of panel in parallel) to give a better answer. The basic answer is:

• For panels in series, match Imp within 10% (i.e., 10 amp with 9-11 amp Imp new panel). If you can match withing 5% or better--That is ideal
• For panels in parallel (or strings of panels in parallel), match Vmp within 10% (i.e., 400 Volt Vmp +/- 40 volts)--5% or less mismatch is even better.

As you also have found, matching new panels to replace old/broken panels can be a pain too (mfg. go out of business, old 140 Watt panels from 15 years ago are now 300+ Watt production/low cost panels of today).

My big question here is... If you have (for example) 2 parallel strings of 400 Volt Vmp each--+/- 20 to 40 volts (5% to 10% mismatch) means that the replacement panel voltage can be almost anything (Vmp range of 17.5 to 55 volts)... Just for "sanity sace", matching with any Imp~7.4 Amp panel (+/- 10%) with a Vmp~30-36 volts should be fine.

And, depending on your array mounting--You might be limited a bit by the panel dimensions (fixing a larger panel in a "smaller" rack space--Could be a pain. Finding an equal size or slightly smaller panel may make for easier installation/replacement).

Also note--Check the polarity of the MC4 connectors... I would not put it past the mfg. to have a different +/- vs male/female connectors out there.

The issues you can find with mix/match.

-Bill