A colleague of mine says he read in bs7671 that equipment in lofts may need an Arc Fault Detection Device.
I can't find such a requirement, perhaps someone here has heard of it?
A colleague of mine says he read in bs7671 that equipment in lofts may need an Arc Fault Detection Device.
I can't find such a requirement, perhaps someone here has heard of it?
As close as practicable, to reduce round-trip losses through volt drop.
Indeed - and not just direct losses from voltage drop - when charging the charger uses voltage to determine battery charge state - too long/thin cables and charger/inverter will think the battery is full well before it is, and empty while there's still some charge in it. (There are methods to compensate for that, but they have limits - e,g. max 1V difference).
- Andy.
when charging the charger uses voltage to determine battery charge state - too long/thin cables and charger/inverter will think the battery is full well before it is, and empty while there's still some charge in it. (There are methods to compensate for that, but they have limits - e,g. max 1V difference).
This isn't always the case with modern battery management systems, which can measure voltage, temperature, etc, and regulate current, locally at the battery, and communicate local metrics to the EEMS at the inverter via EIA-485 (modbus/canbus or similar) - it really depends on the manufacturer's approach.
Indeed - that was one of the "methods" I obliquely referred to (others include separate voltage sensing cables from the charger/inverter to the battery) - but even if the charger/inverter knows better the state of change, it doesn't necessarily mean it can compensate for it entirely - a Victron system I'm looking at at the moment for instance is only capable of increasing the charge voltage by 1V (0.5V for each of the +ve and -ve cables?) and I suspect in discharge mode there will be similarly be limits to what the inverter will accept.
- Andy.
Indeed - that was one of the "methods" I obliquely referred to (others include separate voltage sensing cables from the charger/inverter to the battery) - but even if the charger/inverter knows better the state of change, it doesn't necessarily mean it can compensate for it entirely - a Victron system I'm looking at at the moment for instance is only capable of increasing the charge voltage by 1V (0.5V for each of the +ve and -ve cables?) and I suspect in discharge mode there will be similarly be limits to what the inverter will accept.
- Andy.
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