Recent content by RCinFLA

Surge spec without time duration specification is meaningless. For A/C compressor you need about 0.5 seconds of duration for the surge load. Power factor is another issue. HF inverters don't like poor power factor loads. During startup surge on A/C compressor the power factor can be in the...

Maximum Voc has little to do with illumination shortcomings. As long as there is enough illumination to overcome panel self-leakage shunt current the panel will go to Voc.

You should be able to treat each compressor as its own independent unit tied to the compressor contactors. It would require two Easystarts. Easystart is only engaged during compressor startup and is bypassed during Run mode. You probably want to remove startup delay at least to larger...

Reason for Columb counter use is to judge SoC under cell current loading and charging conditions where there is overpotential voltage slump or bump screwing up OCV vs SoC relationship. OCV is determined by electrode chemistry. Only thing that will effect OCV is internal leakage current that...

Most hybrid inverter do. - Pass-through relay open, grid forming. - Pass-through relay closed, grid following. Closing pass-through relay is based on first detecting AC voltage present on AC input then aligning inverter's voltage/freq/phase (becoming a slave) before closing pass-through relay...

10 foot cable length pair (pos and neg) 20' total path length. fine strand copper welding cable 300 amps continuous current. 00 = 1.68 milliohms = 0.505v total voltage drop @ 300A, 151 watts of cable loss heating 000 = 1.34 milliohms = 0.401v total voltage drop @ 300A, 120 watts of cable loss...

There is a limit on voltage between the data line twisted pair and any reference ground. There is basically three grades of quality for USB to RS485 converters. 1) lowest, shares USB +5v to power RS485 converter chip. No ESD protection. 2) medium - shares USB +5v to power RS485, has ESD...

Primary wear on pass-through relays is grid-glitches and collapse. Inverter pass-through relay releases its parallel grid connection when grid drops out and inverter momentarily gets overloaded trying to power the collapsed grid causing pass-through relay to release contact connection under...

The difference is just whom is in charge of being AC phase master and who is AC phase following slave. A battery powered hybrid inverter can switch between being a slave to grid phase or standalone master for off grid AC coupled PV GT inverters. For hybrid battery powered inverter, when AC...

EG4 uses a standard PV boost SCC taken from a 230vac AIO HF inverter that uses a 500vdc internal HV DC bus for 230 vac PWM sinewave switching. For 120vac EG4 which has a 250vdc HV DC bus, it follows the 500 vdc boosted SCC output with a push-pull down converter DC to DC converter that has a...

SCC is a boost only converter. Output of SCC must not exceed 500vdc. If array exceeds 500vdc it will just pass through boost diode of boost converter and overvoltage 500 vdc internal bus of inverter. Vmp is typically 0.81 to 0.85 of Voc for silicon panels with good illumination level. If max...

It may be because of array Vmp.. There is a maximum array current to each SCC input. When that current is reached it will self limit. Max power will be that limit current times whatever the Vmp is. Lower Vmp (<200 vdc) arrays will not max out the inverter's PV power generation capability.

You must design for Voc max at coldest temperature. Usually in the morning after a cold night. Without any load on panel, the panel will approach Voc when illumination level generates current that exceeds the inherent shunt leakage current of panel. This is common in morning sunlight levels...

If your boat runs on gasoline you have another consideration of wanting to avoid sparks setting off gasoline vapors trapped under floorboards.

In several months, yes. Not significant in a few weeks. LFP cells have between 0.2% total capacity/month to about 6%/mo. worse case for self leakage rate. Leakage is greater when ambient temperature is higher and when cells get older . All cells will unlikely have the same leakage rate. Over...