I just purchased a brand new Morningstar TS60 off ebay. It was an "open box" purchase, so i got a decent discount. Unit received looks to be in perfect/new condition. All knockouts were in place, so it doesn't appear to have been used. However...
After installation, the unit is flashing Yellow/Red lights together and then the Green light. (Y/R, G). The manual states that this is an overload condition.
Details:
The charge controller is in Charge mode (dip switch 1 is down/off).
After 3 days of operation, the lights are still flashing in this sequence.
Pressing Reset button appears to do nothing.
Voltage is 48v nominal. Array measured voltage is 61v.
The max charging amperage I've measured is 41 amps, which is well below the 60 amp rated current. The lights flash even when amperage is much lower, eg 25 amps. I haven't yet observed when it is super low, eg 5 amps.
There is a C40 mounted next to the ts60 that is handling a 2nd array of approx the same size, ie 41 amps max current.
Both controllers are mounted on top of a Trace 250 DC disconnect box. Which is made for mounting two C40 on top. Even still, they are only about an inch apart and I worry a bit about excessive heat.
As a test, I disconnected (turned off breaker) for the array that feeds the C40 for a few hours. No change on the TS60.
The unit appears to be operating normally other than this LED alert.
Analysis:
I'm leaning towards the idea that I got a faulty unit (perhaps the reason for the open box), and my next moves should be to (a) call morningstar tech support and/or (b) return the controller to the ebay seller.
Also:
I would like to use the On/Off (telecom) mode of the controller which is supposed to generate less RFI. The manual recommends against using it, citing "numerous advantages" of the regular PWM mode, but does not enumerate those or give any additional reasoning. It seems to me that On/Off is doing the same thing, but just much slower, ie seconds rather than milliseconds., and I don't see much problem with that.
Questions:
1. Has anyone seen this fault/error when the unit is way below rated current, or have any recommendation?
2. Does anyone have more info on the differences between regular PWM and On/Off mode? What might be any "real" tradeoffs to using either mode? Have you tried both, and what were your experiences? Did you measure RFI or "dirty electricity" before and after?